AudioCircle

Audio/Video Gear and Systems => The Lab => Topic started by: JoshK on 9 Mar 2009, 07:20 pm

Title: What equipment are you currently working on?
Post by: JoshK on 9 Mar 2009, 07:20 pm
Based on discussion in the "What equipment have you built recently?" thread, this topic seems to warrant its own thread.  Its always fun to gab about stuff you are working on currently as one usually has a lot of excitement about their current project.  It also might inspire others.  That is after all one of the benefit of diy related forums.

This weekend I was finishing up my Aikido preamp.  Its been a really long time (>1 year) since I stuffed the boards, but putting it all together in a chassis with connectors, selection switches and volume control, building the chassis and the PSU all took considerbly more time than expected.  Worthwhile it was though.

I didn't fire it up yet as I re-modeled the PSU in PSUDII and decided to change some components in the power supply.  I am awaiting a cap to use as a quasi cap input supply (small C, in a cLCLC supply).  I added the other LC section, as my original PSU was just LC, and that dropped ripple to a predicted 3mV level and the small c is being added to bring voltage level back up to around 300V.  The result is a PSU that has low ripple, good transients and doesn't ring. 

Since the Aikido stage is nicely self adjusting, I will like fire up the preamp san small-c to see how it sounds and works.  It is easy to add the cap after the fact. 

Secondly, my speaker project is coming along. I machined the baffles to countersink the waveguides (PITA!).  Next, I need to glue the waveguides to the baffles and then bondo and sand the seams to be seamless.  Also, more fiberglass is going to be added to the back of the waveguides for added rigidity and dampening.  My local Pepboys had all the necessary supplies as well as various primers and sealers for prepping the baffles for painting. 

I've been reading up on TL theory from quarter-wave.com.  I got the hair-brain idea to build a closed TL cabinet for the mid.  The idea is to absorb the back wave as much as possible so it is not reflected back through the cone.  Since, I plan to high pass the MT at somewhere between 200-300hz, the TL is targeted for ~200hz and tapered. 

The downside to the TL enclosure is the added size due to all the braces that make the line (folded).  So this will add to size, I just need to see how big this will be.

There is a website, I saw recently, of a RAAL/PHL MTM  (http://jirihifi.com/jKN%2001.htm) that uses such a cabinet.  That was partially the inspiration, JohnJ of AES was the other.

P.S. contact me if you know how to design such a TL, I'd love some verification since this is new territory for me.

Title: Re: What equipment are you currently working on?
Post by: whubbard on 10 Mar 2009, 01:15 am
I've posted this elsewhere, but I'm doing a DIY turntable with a Mark Kelly controller.
(http://www.westsweb.com/Turn Table.jpg)

-West
Title: Re: What equipment are you currently working on?
Post by: JoshK on 10 Mar 2009, 01:19 am
Is your platter being made from OSB? 
Title: Re: What equipment are you currently working on?
Post by: whubbard on 10 Mar 2009, 02:47 am
Nope,
Lead filled Birds Eye Maple.

There is more about it in the first post here:
Turntable Build (http://www.audiocircle.com/index.php?topic=65753)

This rest of the thread is currently hijacked with a discussion I'm okay with, but that means only the first post is relevant to the TT.

-West
Title: Re: What equipment are you currently working on?
Post by: Wayne1 on 11 Mar 2009, 03:35 am
I'm doing very nasty things to an old pair of New Larger Advent speakers.

(http://www.audiocircle.com/image.php?id=18729)

I just cut out the baffle to install a JBL waveguide.

I have to refoam the woofers, next.

I will be using a Selenium D220Ti compression driver with the waveguides.

I love my VMPS, but you can never have enough speakers  :wink:
Title: Re: What equipment are you currently working on?
Post by: analognut on 11 Mar 2009, 03:57 am
Currently my Sota Star is at Sota having a new sapphire thrust plate installed.
Also upgrading to zirconium ball and Vinyl-Format mat. Which means I'll basically
have a Nova when they're done with it. I just got this outfit a few weeks back and
I wanna treat that SME V arm right!  8)
(http://www.audiocircle.com/image.php?id=18710)
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 16 Mar 2009, 12:16 pm
I currently have a few projects brewin

First and farthest along is a Pearl MM/xono MC phono stage
Next I got all the parts for a set of Nathan 10 speakers from Gedlee
Finally I have most of the parts for a Akidio linestage
Title: Re: What equipment are you currently working on?
Post by: JoshK on 16 Mar 2009, 02:17 pm
This weekend I worked on my shop.  I set up my lab table, which had been taken down for well over a year, maybe two.  No more soldering on the dining room table.  I pulled my O'scope out (Kikusui 5ch 100Mhz). 

Title: Re: What equipment are you currently working on?
Post by: BillB on 16 Mar 2009, 02:31 pm
Oh I envy you! I need to build myself a workbench in the back of my theater as I am a dining room table solderer too...makes it a real pain when the pesky family wants to eat dinner and stuff.  :lol:
Title: Re: What equipment are you currently working on?
Post by: jwb on 16 Mar 2009, 04:06 pm
First post here, just wanted to introduce myself.  This site looks great.  Can't believe I didn't find it before now.

I've been in the lab for a week working on a shunt regulator for my new solid-state pre.  The preamp uses a CS3318 attenuator and OPA1632 line drivers.  There are three balanced inputs and six single-ended inputs, DC, AC, or transformer coupled, controlled with relay logic.  The shunt provides ±9V power for the attenuator and line drivers. 

Now that I have the shunt figured out I can finish up my drawings and I expect to have this preamp built within the next few months, give or take.

My other project right now is to build an infrared remote control for my Akai GX636 reel-to-reel tape deck.  Haven't really got started on that one.  If anyone knows the pinout for that connector, please spill the beans.

(http://octothorpe.barelyconnected.net/~jwb/theremin.jpg)
Title: Re: What equipment are you currently working on?
Post by: JoshK on 18 Mar 2009, 03:07 pm
Welcome jwb.  Looks like a nice project. 
Title: Re: What equipment are you currently working on?
Post by: TomS on 18 Mar 2009, 03:36 pm
Welcome jwb.  Nothing like breadboard and clipleads in the morning  :thumb:  Tom
Title: Re: What equipment are you currently working on?
Post by: 56oval on 19 Mar 2009, 01:01 pm
Hi ,I think this is my first post .I've been collecting parts over couple of years for an active speaker project ,drivers are PHL's,Ravens and a 15" Tempest-X driver .The amps for the R1 & PHL's are 300B SET's ,I no nothing about electronics or speaker design but have a couple of mates to help me and I can follow a circuit diagram  :duh:.Here's a couple of sketch's of the amps and speakers.The amp circuits have been drawn up by a friend and he winds all his own Tx's.
(http://i55.photobucket.com/albums/g158/malcolm_05/Midrangecabbasscab.png)
(http://i55.photobucket.com/albums/g158/malcolm_05/midrangeamp.png)
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_3394.jpg)
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_1372.jpg)
This is a philips based TDA1541 dac I modifed on the right you can just see my 6H30pi pre .
(http://i55.photobucket.com/albums/g158/malcolm_05/diyfi001.jpg)

Cheers
Title: Re: What equipment are you currently working on?
Post by: Bill O'Connell on 19 Mar 2009, 01:14 pm
Just finished stripping down a pair of University Acoustic Baton cornerhorn speakers from the late 1950's.They are now residing in my computer room.May have to do some work on the N-3 crossovers though.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 19 Mar 2009, 01:21 pm
56oval, welcome!

Fantastic render and serious projects you have going there.  Who is your builder?  They look like a good mate to have!

What PHL drivers are you using for your TMW?  Looks like a cool project. 
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 19 Mar 2009, 01:21 pm
Quite the project you have going there 56oval, that is a LOT of iron.  :thumb: :thumb:

jwb, that sounds very cool. I thought "regulator" as soon as I saw the breadboard. Not sure why but that was my immediate thought.
Title: Re: What equipment are you currently working on?
Post by: 56oval on 19 Mar 2009, 01:33 pm
56oval, welcome!

Fantastic render and serious projects you have going there.  Who is your builder?  They look like a good mate to have!

What PHL drivers are you using for your TMW?  Looks like a cool project. 
Thanks Josh & Mike
My mates new website isn't up and running but here it is contact details are correct http://www.black-art.com.au/ ,he drew the circuit for me  and its up to me to put it together   :D.
The PHL's are 6.5"1120 & 10" 3020 ,I did have the PHL12" 4530 but swapped for the 10" the main reason I rather have SS running the 90hz down .

Cheers
Title: Re: What equipment are you currently working on?
Post by: JoshK on 19 Mar 2009, 01:38 pm
Would love to see the circuit if you have it in electronic form.
Title: Re: What equipment are you currently working on?
Post by: 56oval on 19 Mar 2009, 01:49 pm
Would love to see the circuit if you have it in electronic form.
Lucas ask me not to post the ciruit until the amps are up & running and to make sure everything is ok ,hes put alot of effect into the design .

Cheers

Title: Re: What equipment are you currently working on?
Post by: JoshK on 19 Mar 2009, 01:58 pm
That's fair and understandable.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 22 Mar 2009, 10:21 pm
I have a couple pics of the Abbey clone speaker baffles.

Here is a shot of what it took to machine my fiberglass version of the waveguides.

(http://www.audiocircle.com/image.php?id=18901)

(http://www.audiocircle.com/image.php?id=18903)

(http://www.audiocircle.com/image.php?id=18904)

Yesterday I put a 1.25" roundover on all corners.  Using that bit, even with a router table is a bit unnerving.  I did some mild sanding and the baffles look pretty much ready for finishing.  Will need to fill some cracks in with bondo and then start the tedious process of sanding, sealer, sanding, primer, sanding, primer sealer, sanding, painting, sanding, etc.

Guess I need to start making the rest of the box.  Also need to make bass bin boxes (Lambda TD15X in 5cuft with slot port tuned to 28hz). 
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 22 Mar 2009, 11:49 pm
After a meeting with a local electronics expert who shall not be named I have completely taken apart my Zv9 and will be laying it out differently to fix a small hum issue. 
Title: Re: What equipment are you currently working on?
Post by: SharkyRivethead on 23 Mar 2009, 04:02 am
 Hey folks, after having had some problems with the amp in a sub, and finding out that there was a major complaint about poor design work with this piece in particular. I'm now thinking about rebuilding a amp from scratch. I've already replaced a lot of caps and resistors on the boards. If it was a bad design, what's the point of wasting anymore time on it.

 Is there any good resources for this type of stuff that someone can recommend? 

  Also, I don't know where you guys buy your electronic parts from. My wife is in the electronic brokerage business. She turned me on to a company called Mouser Electronics. They sell to the public and have just about everything you can think of.
http://mouser.com/

Thought it might be helpful.
Title: Re: What equipment are you currently working on?
Post by: aerius on 25 Mar 2009, 11:31 pm
I'm in the planning stages for an all DHT headphone amp, I have the cases (large baking pans from the flea market) picked out & painted plus all the transformers, capacitors & chokes I'll ever need.  I just need to decide which tubes I want to use and see if I can pick up a stash of nice sleeper tubes for cheap.
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 26 Mar 2009, 01:28 am
I rebuilt the B+  power supply in my preamp last weekend with all polypropylene caps, no more electrolytic caps in there. I was using an Elna Cerafine dual section but another AC member offered up 4 22uF/600V Solen polypropylene for dirt cheap so I thought I'd give it a try. I took the opportunity to add a choke as well so it's now CLCRCRC as 5Y3GT -> 4uF -> 5H -> 44uF -> 1K -> 44uF -> 1K -> 22uF. Feeding the Mac 275 I used to have a little noise but the new choke seems to killed even that as I can't even tell the system is on with the 95dB Abbeys.

As for the sound, it seems very nice. A little less "tube like" but with more apparent clarity and improved bass. Certainly worth the minimal cost and a few hours worth of time.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 19 Apr 2009, 12:23 am
Spent all day outside today bondo'ing my speaker baffles, sanding, bondo, sanding, shellacing.  The shellac is to seal the mdf before primer. 

(http://www.audiocircle.com/image.php?id=19226)

These are moving along slowly but surely. 

Started the Gary Pimm phono preamp.  Basically I figured out the layout and started making the ground plane.

Need to find what I did with my bass bin (TD15X) dimension sketches.  :duh: 

BTW, this was my first time using bondo.  Very useful!  However, the stuff really stinks bad.  It also dries so damn fast.  I wish it would stay wetter longer so you don't have to keep mixing it up as you go. 

Title: Re: What equipment are you currently working on?
Post by: JoshK on 20 Apr 2009, 01:09 am
Got to do some priming today.  Weather stayed really nice.   8) 

Man does MDF ever drink up the primer, even with shellac covering.  I had to made a HD run as I dusted my two rattle cans.  I guess I didn't get enough shellac on (one rattle can for two baffles).

Title: Re: What equipment are you currently working on?
Post by: nullspace on 20 Apr 2009, 03:06 pm
Hi Josh,

The baffles are looking good. Are you building the Pimm phono 'stock' or are you making any changes to the circuit? I wonder just because Gary and Kurt Strain before him run those tubes at an awfully low current, sacrificing some of the benefits of high gm tubes. Of course, they know way better than me, but I was just wondering.

Regards,
John
Title: Re: What equipment are you currently working on?
Post by: JoshK on 20 Apr 2009, 03:25 pm
Re: Pimm's phono

I am planning to build it with little differences initially. The differences I will make are using the Pimm/Swenson regulator in lieu of the tube shunt reg and using the self-bias CCS instead of the battery bias CCS.  This I disgused with Gary and he thought it was a good idea.

As far as low/high current, I think this may not have to benefits you perceive as the CCS's mu output is where the output is being taken.   Therefore the CCS drives the EQ and the output, not the tube, so the higher current isn't needed to lower the Zout.   The tubes should last for ages at the lower point. 

I haven't (for obvious reasons) played with the op points, either on paper or in circuit, to determine the linearity, but I trust Gary.

Title: Re: What equipment are you currently working on?
Post by: nullspace on 20 Apr 2009, 03:38 pm
Hi Josh,

The benefit of high gm tubes I was referring to is low noise. When you run high gm tubes at low current, well, they become low gm tubes and are more prone to noise. I knew rp was a non-issue with the mu-follower output from the CCS.

Did you find a suitable output transformer?

Regards,
John
Title: Re: What equipment are you currently working on?
Post by: JoshK on 20 Apr 2009, 04:16 pm
For output tranny, I plan to use Magnequest B7's.  4:1 parafeed nickel. 

The noise is a good point, one I hadn't thought of. 
Title: Re: What equipment are you currently working on?
Post by: nullspace on 20 Apr 2009, 04:45 pm
Just to be clear, I wasn't attempting to point out a flaw -- just something to think about. IIRC Gary inherited the operating points from Kurt Strain, who has posted his reasons for choosing the low-current op over at AA somewhere. There's a project over at diyAudio using the 6GK5 at more textbook currents here (http://www.diyaudio.com/forums/showthread.php?s=&threadid=130983), which I suspect you've already seen.

If you talked the project over with Gary, I'm sure he mentioned this, but on the off-chance that he didn't, the MQ trannies would like to see a higher value parafeed cap than the one GP is using in his preamp, on account of the greater inductance. I think he has said that, in part, he used the UTC transformers so he can get away with a smaller cap.

Regards,
John
Title: Re: What equipment are you currently working on?
Post by: JoshK on 20 Apr 2009, 09:54 pm
Good point also about the caps/inductance.  I hadn't done the calculation yet for the -3db point.  I, though, have lots of suitable caps of varying values.  I know it is not PC to use a large value cap in series with the signal but a poly cap bypassed by a smaller teflon or silver mica ought to do well.
Title: ...Winter Blues has moved to Summertime Blues....
Post by: jeenie67 on 21 Apr 2009, 02:28 pm
.....The Bloody Who!  Well being somewhat incapacitated for the next four or five months I thought I'd ship some pics of all my busy-work to keep me occupied other than the Boob-Tube.     My 1920's Victrola is my favorite. This will get a cherry wood cabinet and will be constructed as a floor stander.  The 16" Altecs out of a pair of "W" enclosures are due for a complete recone as they are hard pressed in their duties as studio monitors and sound reinforcement for my  band.  IC re-assembly and changeover to complete balanced lines for all my components fills in the time between re-capping my tube radio collection....I love tubes....maybe it's the soft glow they exhibit....like a campfire.   Then there's the vintage oak cabinet all the audio/theater components are housed in....that gets a complete new hairdo too!
(http://www.audiocircle.com/image.php?id=19257)
(http://www.audiocircle.com/image.php?id=19257)
Title: Re: What equipment are you currently working on?
Post by: dyohn on 21 Apr 2009, 03:52 pm
I'm building a Pass Labs First Watt B1 passive buffer feeding a diyparadise Charlize 2 t-amp as a little integrated amp for my office.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 22 Apr 2009, 02:59 am
everyone is probably sick of the innundation of pictures, but have been trying to keep pictures of steps along the way.

I think the point is to perfectly smooth out all the warts before adding primer, but I guess i was getting antsy.  I added a couple coats of primer to the baffles. I still need to do more bondo to fully hide the waveguide seams.  You can really see them with the primer added, which aids in seeing them to fix them.   :roll:

(http://www.audiocircle.com/image.php?id=19274)
Title: Re: What equipment are you currently working on?
Post by: lonewolfny42 on 22 Apr 2009, 08:34 am
Quote
..everyone is probably sick of the innundation of pictures..

On the contrary Josh...their coming along nicely !! 8)
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 22 Apr 2009, 11:08 am
Very nice Josh!  aa

Mariusz :thumb:
Title: Re: What equipment are you currently working on?
Post by: Levi on 22 Apr 2009, 01:42 pm
I am not really a tweaker. 

Here is my recent project.  Please don't ask me for details as this is a fairly simple tweak.

It started as a CablePro NoiseTrapper
(http://i149.photobucket.com/albums/s43/ofier/Stereophile/Main%20System/CablePro%20NoiseTrapper/IMG_2339.jpg)

Then I added snake oil  :lol:
(http://i149.photobucket.com/albums/s43/ofier/Stereophile/Main%20System/CablePro%20NoiseTrapper/IMG_2341.jpg)

So far so good.  No smoke or fires comes out when I plugged it in.  It is a much lower noise floor :thumb:
(http://i149.photobucket.com/albums/s43/ofier/Stereophile/Main%20System/CablePro%20NoiseTrapper/IMG_2344.jpg)


Cheers
--Levi
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 22 Apr 2009, 01:46 pm
I smell competition for well regarded Kaplan line of products. :lol: :lol:

Mariusz :thumb:
Title: Re: What equipment are you currently working on?
Post by: Levi on 22 Apr 2009, 01:48 pm
:lol:  :thumb:
Title: Re: What equipment are you currently working on?
Post by: Occam on 22 Apr 2009, 04:33 pm
I smell competition for well regarded Kaplan line of products. :lol: :lol:

Mariusz :thumb:

Absafriggn'lootly, I can't wait to see what Levi comes up with for powercords. 8)

Levi - Nice addition of the parallel capacitor filter :thumb: How does it compare in listening tests to your Blue Circle powerbar with its own built in parallel capacitor filter?
TIA -Paul
Title: Re: What equipment are you currently working on?
Post by: Levi on 22 Apr 2009, 04:45 pm
Thanks Paul.  I have not done any listening test. 

I am happy with the modified Hammond powerbar (Blue Circle).  I am planning on installing the CablePro in my son's room.

--Levi
Title: Re: What equipment are you currently working on?
Post by: satfrat on 22 Apr 2009, 05:04 pm
I am not really a tweaker. 

Here is my recent project.  Please don't ask me for details as this is a fairly simple tweak.

It started as a CablePro NoiseTrapper
(http://i149.photobucket.com/albums/s43/ofier/Stereophile/Main%20System/CablePro%20NoiseTrapper/IMG_2339.jpg)

Then I added snake oil  :lol:
(http://i149.photobucket.com/albums/s43/ofier/Stereophile/Main%20System/CablePro%20NoiseTrapper/IMG_2341.jpg)

So far so good.  No smoke or fires comes out when I plugged it in.  It is a much lower noise floor :thumb:
(http://i149.photobucket.com/albums/s43/ofier/Stereophile/Main%20System/CablePro%20NoiseTrapper/IMG_2344.jpg)


Cheers
--Levi


Sure looks like you're becoming a tweekfreak to me Levi. :dance: Hey, how about a couple large Bybee's (http://www.audiogon.com/cgi-bin/cls.pl?accstwek&1245210070&/Bybee-Large-Quantum) on the ends of the hot/neutral wires coming off the IEC Levi. Better yet, make it 3 large Bybee's (http://www.audiogon.com/cgi-bin/cls.pl?accstwek&1245210070&/Bybee-Large-Quantum) and include the ground also. Try it, you'll like it. I did. :thumb:

Cheers,
Robin
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 22 Apr 2009, 05:11 pm
Bybee on the Earth GND?  Now thats funny. 
Title: Re: What equipment are you currently working on?
Post by: satfrat on 22 Apr 2009, 05:28 pm
Bybee on the Earth GND?  Now thats funny. 

Talk to Wayne Waananen of Bolder Cable.  :o

Or just laugh. :lol:

Cheers,
Robin
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 22 Apr 2009, 06:43 pm
What does it do?  When does electricity flow through it?
Title: Re: What equipment are you currently working on?
Post by: JoshK on 22 Apr 2009, 07:09 pm
Guys, if you want to discuss the merits of bybees, please don't use this thread to do it, with all due respect.  Levi was right to share his project, but discussion on bybees belongs elsewhere (one can hope not the lab for my sake).  :icon_lol:
Title: Re: What equipment are you currently working on?
Post by: BillB on 22 Apr 2009, 07:45 pm
Currently in the design phase:

EL84 SE amp using 6j6 as driver tube.

Title: Re: What equipment are you currently working on?
Post by: satfrat on 22 Apr 2009, 07:56 pm
Guys, if you want to discuss the merits of bybees, please don't use this thread to do it, with all due respect.  Levi was right to share his project, but discussion on bybees belongs elsewhere (one can hope not the lab for my sake).  :icon_lol:

Sorry Josh, my posts saw a simple off the cuff suggestion for Levi only and wasn't meant to be a topic of discussion. That's why I referred sts9fan's comments to (a much more informed than I) Wayne Waananen for more info. Evidently that suggestion wasn't adequate enough, I had no intention of taking it any further than that myself. :D

Cheers,
Robin
Title: Re: What equipment are you currently working on?
Post by: cryoparts on 22 Apr 2009, 09:42 pm
I'm in the planning stages for an all DHT headphone amp, I have the cases (large baking pans from the flea market) picked out & painted plus all the transformers, capacitors & chokes I'll ever need.  I just need to decide which tubes I want to use and see if I can pick up a stash of nice sleeper tubes for cheap.

Cool!

Lee
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 23 Apr 2009, 12:50 am
Finished. But will try few more tweaks and recommendations from fellow members in the future.
I am not sure if this project qualifies to be in this thread  :dunno:- if not, sorry. Some of the build progress can be viewed in my gallery.

Cheers
Mariusz :thumb:

(http://www.audiocircle.com/image.php?id=19280)

Title: Re: What equipment are you currently working on?
Post by: BobM on 23 Apr 2009, 12:34 pm
I'm planning on building a headphone amp soon. Thinking of the Millet Mini-Max with some boutique upgrades (of course). Beezar.com is pulling together a kit to make it easy and source all parts and plans from just one vendor.

Unless of course someone has another suggestion that they feel may be better than the Mini-Max?

Bob
Title: Re: What equipment are you currently working on?
Post by: jrebman on 23 Apr 2009, 08:33 pm
Two projects now well under construction:

First is a Millet Minimax headamp.  With a little help from my dad over the past few days I was able to get the entire board stuffed and soldered, except for the 1n4148 diode, which Mouser sent me an SMT version of.  Once that's in, then it's time to wire it all up and mount it in the custom Lansing enclosure.  Tweaks are Black Gate NX s for output and cathode bypass caps, with no film bypasses, 15 ohm Audio Note tantalums for the output resistors, Vampire RCA jacks and OCC litz braided wiring to board, Herbie's baby booties for feet, and a Maple thingamabob for the volume knob.  No LEDs.

Second is the Bottlehead s.e.x. amp -- finishing mechanical construction of top plate, gluing up temporary base, and just received 2 .1 uF Ampohm tin foil PIOs for coupling caps, and two Ampohm 2.2 uF metal polys for parafeed caps.

Nickel pinstrip MQ iron is on order, and CCS boards are next.

I'm building this bone stock to start, then slowly upgrading and tweaking as I go along.  This will eventually be the headphone amp for the bedroom, and will also drive the zigmahornets that will live there too.

Wish I could take some pics because the minimax board is quite dense and I'm kind of proud how it turned out so far.

-- Jim
Title: Re: What equipment are you currently working on?
Post by: BillB on 30 Apr 2009, 02:50 pm
Newest project:

Peter Millet's Low-Mu preamp.

http://www.pmillett.com/lowmu_preamp.htm

Mine is going to be a single in/dual out (I only use 2 sources and really want to put some nice RCAs and really would rather not have a switch...)

I have ordered as top notch as I can afford for parts, still need to get the power transformer, choke, chassis, and RCAs.

Tubes will be EH 6CA7H for CCS, Svetlana Winged =C= 6as7, and EH 5U4GB got rectifier.

I am really looking forward to hearing this thing.
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 30 Apr 2009, 09:36 pm
Neighbor....

I'm up in south Forsyth county, near 141 and McGuiness Ferry, just over the Fulton county border. Coincedence.... I'm currently putting together an interperetation of Pete's Low-Mu preamp myself. I have the chassis and top plate done and am currently wiring it all together. I've taken some liberties with the power supply.

If you ever want to toch base and compare notes drop me a line


I'm also putting together bits for a DAC (AD1865 non oversamplung) and my new phono section (2 6C45p/ LCR/ E188CC) is about at
about 80% done.

Last but not least, I'm just starting to eyeball and researching doing up a Schroeder clone tonearm for a 401 I've just acquired.

Jeff Davison



Newest project:

Peter Millet's Low-Mu preamp.

http://www.pmillett.com/lowmu_preamp.htm

Mine is going to be a single in/dual out (I only use 2 sources and really want to put some nice RCAs and really would rather not have a switch...)

I have ordered as top notch as I can afford for parts, still need to get the power transformer, choke, chassis, and RCAs.

Tubes will be EH 6CA7H for CCS, Svetlana Winged =C= 6as7, and EH 5U4GB got rectifier.

I am really looking forward to hearing this thing.
Title: Re: What equipment are you currently working on?
Post by: BillB on 1 May 2009, 12:51 am
Oh wow!

I have a Buffalo DAC that I still need to put together.  :icon_lol:

Here are some parts: (for the preamp)

(http://img16.imageshack.us/img16/8789/dsc09429.jpg)

(http://img527.imageshack.us/img527/557/dsc09431.jpg)
Title: Re: What equipment are you currently working on?
Post by: bluesky on 2 May 2009, 10:42 am
I have a project that I never seem to get around to finishing but hopefully completion won't be too far off now  Some time ago I bought two 15 watt Class A amp kits which were on special from one of the local Australian electronics suppliers.  The reason for this particular amp being chosen was a) it was cheap, and b) it has the remarkable THD specs of just 0.00006%! 

I then bulit up one of these amps using the standard industrial grade components.  The second amp has been built using premium "boutique" parts which I sourced mainly over internet from people's leftover parts which were surplus to their requirements.  These parts include Caddock 132's and Vishay RN60 resistors and the caps are mainly Elna Cerafines plus a couple of Black Gates for the amp boards.

The power uses high speed soft recovery diodes, RN60's and Nichicon Muse power supply caps whilst the other uses standard "no name" generic caps and resistors.

The PCB's are now complete and I now need to build some chassis to house these amps.  I intend on using identical chassis and then conduct some listening tests to see what effect the premium parts have on the sonics.  My reasoning is that with such low distortion specs any parts differences should be readily apparent.  Having two identical chassis should make it a more conclusive test as this should enable me to audition the two amps without knowing which amp is which and so provide an objective listening test.

I will post the results once everything has been finished and the listening tests done.

Cheers

Bluesky
Title: Re: What equipment are you currently working on?
Post by: bluesky on 3 May 2009, 05:09 am
I have just realised that this proposed project of mine is illegal on this circle and therefore I retract my previous post.  I really should have thought it more before writing up such a post, my apologies for this inadvertant error.

Bluesky
Title: Re: What equipment are you currently working on?
Post by: JoshK on 3 May 2009, 05:17 am
Why would it be illegal?  Enlighten us.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 4 May 2009, 01:23 am
Bass bins for my speaker project have been designed.  Modeled and drawn.   I am sitting here trying to figure out what is the best way to build it.

I decided on JohnJ's suggestion for a TD15X in a 5cu.ft. enclosure with a 3" x 16" slot port 26" long (wrapped up the back).  Except, I decided on a twist.   Instead of a standard slot port, I am going to do 4 1.5" x 4" slots on each side of the cabinet, Onken style.  The outer dimensions come to 23" x 22.5" x 31".  Not too bad.  I can stuff the ports if I decide I don't like the ported tuning, which would create an aperiodic tuning that would be pretty close to ideal, I think. 

This gives a 28hz tuning and from memory the -3db point is upper 30's and -10db in mid 20's.  95db/w for most of the passband. 

I am thinking of using the MT baffles (shown previously) in semi-open baffles above this.  I am considering toying with the muffler idea that MBK was demonstrating in diyaudio's cardiode thread.

#2 I was painting my TT plinth.  Its starting to look semi-decent in a gloss black finish.  It needs some more layers and lots of sanding.

#3 tweaked the Aikido PSU and fired up the Aikido preamp for the first time.  Unfortunately, B+ came in way above predicted at 400V (was suppose to be 300V).  I must have plugged the wrong DCR for my chokes into PSUDII.  Don't know how it would be that off.  Tranformer was actually measured and measured values plugged in.   :scratch:

Title: Re: What equipment are you currently working on?
Post by: GBB on 4 May 2009, 01:27 am
Josh,
Regarding the Aikido PS - is it possible that the tubes aren't drawing as much current as you're expecting?  That's the only thing that I could think of that would cause you to be that much higher than expected.  Unless you've wired things up really wrong.
What type of PS are your using?  Choke input or capacitor input?

---Gary
Title: Re: What equipment are you currently working on?
Post by: JoshK on 4 May 2009, 01:33 am
cLCLC.  Yeah, I really need to measure more but I started on something else. 
Title: Re: What equipment are you currently working on?
Post by: GBB on 4 May 2009, 01:51 am
cLCLC. 

I assume that the small "c" means that you are tuning the power supply voltage with this "c" and that the target voltage is in between what one expects for an inductor input filer and a capacitor input filter.  I've never had good luck predicting the exact value needed for this type of filter - you just need to experiment until it hits your target.

---Gary
Title: Re: What equipment are you currently working on?
Post by: JoshK on 4 May 2009, 03:20 am
That's it.  I was just surprised at how far off it was.  I know the Hammonds run high because of the 115V primary, that adds some.   Still, that is 33% high. 

The good thing was that ripple was immeasurable on the 600V range of the DMM, which it should be.
Title: Re: What equipment are you currently working on?
Post by: tdangelo on 4 May 2009, 03:43 am
I recently swapped out my Usher BE-20 stock crossover with some made by Danny Richie.  Nice guy to work work.  The new networks use very high quality part and build quality is very good.  Although the 20's sounded fantastic with the stock xovers they've gone up a level or 2 in refinment an smoothness.  No more phase issues that really bugged me - bass is pefectly balanced and refined - before bass was just to strong and not as well defined.  The platinum bypass caps will take many more hours of burnin but even at 15hrs they sound very nice.  I'm happy so far.  The job took about 5-6 hrs - it wasn't to difficult but just tedious.  At this point I think it was worth it ;) The lower tweet xover make the tweeter a little more alive but not to hot or shrill - the midrange now produces more vocals since it also plays lower - it sounds much better with less voice out of the woofers. IN all it was a good worthwhile upgrade.
 
Tony
Title: Re: What equipment are you currently working on?
Post by: SET Man on 4 May 2009, 04:23 am
I am not really a tweaker. 

Here is my recent project.  ...

Cheers
--Levi


Hey!

   Whoa! When dose Levi turn in to a soldering iron swinging DIYer?  :o

   I thought he only buy factory made brand name audio components and open only just to take picture of the inside. :jester:

   Anyway, nice works there and have fun :D

Take care,
Buddy :thumb:
Title: Re: What equipment are you currently working on?
Post by: jules on 5 May 2009, 06:49 am
Currently working on:

(http://www.audiocircle.com/gallery/albums/userpics/13273/ST-1_boards%2C_all_6_of_them.jpg)

These boards are part of, what will eventually be a 45W X 2, pure Class A SS amp and pre-amp. It's a DIY from audio-gd and a big project. I might post the build story here as a topic in its own right.

Bluesky: nice project and great dedication to a well designed piece of research. I am guessing that you are holding back on the grounds that you'd be doing A-B testing [banned here on the grounds of generally becoming tedious] but I hope you'll give us your results as your approach is anything but superficial.

Jules
Title: Re: What equipment are you currently working on?
Post by: bluesky on 5 May 2009, 08:45 am
Hi Jules

Much appreciated comments.  I think it would make for a very interesting project but realised that the blind testing was contrary to existing rules.  It is very much a matter of seeing if the premium parts that I am sure we all buy as audiophiles, really do make much of a difference.

I am guilty of buying the occasional expensive cap or resistor and I "think" they make a difference.  However by the time I get to listen to any changes the time delay makes it difficult to work out just how much difference such parts made.  Hopefully I could provide an overview of the results without causing too much distress to anyone.

Bluesky
Title: Pics of my interpretation of Pete Millet's Low Mu preamp
Post by: jeffdavison on 7 May 2009, 12:03 am
Almost done, just have to do the input wiring from the RCA's to the selector switch.

Here's some teaser shots, later I'll post some "up-skirt" shots when done.

My variations are dual rectifed cLCLCRC power supplies ( two p.s.'s but one trans),  and some NOS tubes I had laying around... GZ34's, KT77's and a 421a.

I built the cahssis to match the DC S.E.T.'s I built earlier this year.

JD

(http://www.audiocircle.com/image.php?id=19546)
(http://www.audiocircle.com/image.php?id=19545)
(http://www.audiocircle.com/image.php?id=19544)
Title: Re: What equipment are you currently working on?
Post by: BillB on 7 May 2009, 01:29 am
 :drool: :drool: :drool:

And a WE 421a ta boot.

My pre is jealous and it is still just parts.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 24 May 2009, 02:48 am
Bill,

the pre is up and running. Sounds very nice... still burning in. Dissapates ALOT of heat! more than my SET's.

Since your inthe Atlanta area... I surmise this as the link from you signiture says your based here (home of the $200 etc..) I'll extend an open invitation if you'd like to drop by and audition it.


Jeff


:drool: :drool: :drool:

And a WE 421a ta boot.

My pre is jealous and it is still just parts.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: BillB on 27 May 2009, 10:49 pm
I would love to!
Title: Re: What equipment are you currently working on?
Post by: JoshK on 16 Jun 2009, 12:20 am
Had a couple days off around the weekend.  Mostly worked on the new bathroom and study, the garden, a new kitchen faucet, but today I decided to play with a tube project.  I had received a Tubelab SE board two weeks ago and got most of the parts in last week, so I stuffed the board today.

The Tubelab SE, in case you aren't familiar, is the DHT SE amp with the powerdrive circuit, its not the same as the SimpleSE which uses a more traditional driver and audio pentodes.  I wanted to build another SE amp for comparison and was always intrigued by George's powerdrive circuit. 

I plugged in my JJ 300Bs to see how they fit.  Boy are they a tight fit!  I have about 1/4", if that, between the glass of the two triodes. 

I have a pair of Transcendar 3K 10W OPTs, a James 5H/200mA choke, a couple different power transformers to choose from, and a 85uf motor run cap for the B+ filter.  That about rounds up the choices.  Nude russian teflons for coupling caps.
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 16 Jun 2009, 12:38 am
Hi Josh

Will we see (hear) these eye candy at your place at upcoming "Mini-Rave" ???
If so, what speakers are (will you be) you using with those babies ?

Mariusz :thumb:

Title: Re: What equipment are you currently working on?
Post by: mgalusha on 16 Jun 2009, 12:41 am
I rebuilt my preamp last week. Put in a Swenson regulator and a CCS on each half of the 6SN7 gain tube. Also installed a LDR attenuator, essentially the Lightspeed attenuator but built into the chassis. Supposedly the PS for the LDR attenuator is somewhat critical so I used ultrafast recovery diodes followed by a small 'lytic then a common mode choke, a big cap and feed that into one of the little miniVreg's from AW DIY left over from when I was hacking the DCX's. It has another LC filter and uses a Linear LT1763 reg chip. Works out to a nice quiet supply for the LDR's. Also some lovely polypropylene film bypasses some small panasonic FM caps on the input and ouput of the reg.

The regulator and CCS mods were a big step up and adding the LDR attenuator was also very nice and totally worth the time and expense, which is actually pretty low for the results. This replaced an ALPS pot. Big thanks to Josh K for hooking me up with the Swenson/Pimm regulator boards.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: JoshK on 16 Jun 2009, 03:21 pm
Hi Josh

Will we see (hear) these eye candy at your place at upcoming "Mini-Rave" ???
If so, what speakers are (will you be) you using with those babies ?

Mariusz :thumb:

I was hoping maybe you could bring your Omegas, or do you still have a pair of Omegas?  Otherwise we are stuck with my 89-90db 4ohm MTMs. 

I am not sure if the TubeLabSE will be up and running by the mini-rave as I wanted to get started on my woofer bins.  If it will be running it will be on a bread board, but that might be doable since I don't need to do much apart from clip lead some wires to my transformers and a couple connectors.

Title: Re: What equipment are you currently working on?
Post by: Mariusz on 16 Jun 2009, 07:19 pm
Hi Josh

Will we see (hear) these eye candy at your place at upcoming "Mini-Rave" ???
If so, what speakers are (will you be) you using with those babies ?

Mariusz :thumb:

I was hoping maybe you could bring your Omegas, or do you still have a pair of Omegas?  Otherwise we are stuck with my 89-90db 4ohm MTMs. 

I am not sure if the TubeLabSE will be up and running by the mini-rave as I wanted to get started on my woofer bins.  If it will be running it will be on a bread board, but that might be doable since I don't need to do much apart from clip lead some wires to my transformers and a couple connectors.

Do not go bananas over the Rave. Do what you need to do first. If you need anything specific just let me know.
As to speakers - do not worry Josh, we will think of something that will work with whatever.
Omegas are still in my possession and are not likely to go anywhere soon.
We can have those or I can bring over some "prototype" bipolar speakers which I am still working on. They still need some tuning but I am very happy with the results so far. They are small floor-standers with quite amazing clarity and soundstage. The lower bass is not the last word in seismic stimulations but tuneful enough for average music-lover.

I know that you have a lot on your plate and time is limited, so just let me know when you'll be ready and what can I do to help.

Mariusz :thumb:
Title: Re: What equipment are you currently working on?
Post by: rajacat on 16 Jun 2009, 08:44 pm
Hi Mariusz,

I've been raving about my Omega Hemp Bipoles for a long time so I'm especially interested in your bipole prototypes. It almost seems counter intuitive as to how they can image so well with their opposing drivers whereas the deep sound stage is to be expected. Most of my friends that have heard my speakers are amazed that the little 4-1/2" drivers can project such a large sound stage and pull a disappearing act. Bass is fairly good too however I do run a sub. I imagine that a pair of the Rhymik OB subs would really create a magic synergy. aa

-Roy 
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 17 Jun 2009, 12:12 am
Hi Mariusz,

I've been raving about my Omega Hemp Bipoles for a long time so I'm especially interested in your bipole prototypes. It almost seems counter intuitive as to how they can image so well with their opposing drivers whereas the deep sound stage is to be expected. Most of my friends that have heard my speakers are amazed that the little 4-1/2" drivers can project such a large sound stage and pull a disappearing act. Bass is fairly good too however I do run a sub. I imagine that a pair of the Rhymik OB subs would really create a magic synergy. aa

-Roy

Hi Roy

Absolutely agree with you about the disappearing act of well design bipolar speakers.
In fact my original testing was done in mono (only one speaker) and it almost fouled me into believing that it was stereo reproduction.  :lol:
I had a chance to compare them to few speakers which are collecting dust and some which are my faves in my home. Those includes(ed) - AAD 2001 monitors (sold), Omega Super 8s monitors, my own double mouth horns and Martin Logans Aerius i. 
Without any exaggeration, they were on pare with some and better then most.

Their size (31.5"x10.25"x9.25") has some limitations ofcause and integrating two drivers as well as controlling the back wave is nothing to sneeze at but it can be done with fascinating results.
Just so you know, voicing my speakers is done by ear and frequency response is of absolute no interest to me. When it just sounds right that's when you need to leave your tweaker's ego behind either tho the little devil on your shoulder tells you otherwise.

The biggest challenge and effort was put in controlling the back-wave, cabinet (still working with different materials) and bass response. For cabinet of this size the bass is quite OK and pretty tight. (during the bass test some of my wall metal studs start rattling ......  :wink:)
In general, three characteristics in speaker design annoys me - boomy/unnatural bass, cabinet resonation due to poor construction and forward/HiFi-ish highs.  :(

If you aren't to far and would like to hear these we can  arrange it in a week or two when I will have them finished. Still waiting for my Bamboo veneer and then I am taking them on a short demo trip.

If they ever become available, I'll have them in two different driver choice. Both 8" full range drivers tho. Keeping them affordable will be my priority without sacrificing its performance (if ever).

Cheers
Mariusz :thumb:

P.S

Almost forgot........
speaking of subs - if you like fast, tuneful bass, check  these subwoofers (http://www.musicalsubwoofers.com/dsp_products_subwmagvisu.asp) out. They have few at special pricing as well.



Title: Re: What equipment are you currently working on?
Post by: rajacat on 17 Jun 2009, 07:04 pm
Mariesz,

Thanks for the invitation to hear your prototype bipoles but I'm on the other side of the country (Washington State) :icon_frown:.

My speakers use some sort of multicolored foam to control the backwave. It looks similar to carpet padding but much thicker.

AudioKinesis has an interesting bipole design, The Dream Weavers, that vertically offset the rear drivers from the front drivers. Hmmm... I wonder if tilting the box slightly backwards would perform the same function? I do that with my bipoles.

 Well... maybe a thread could be devoted to bipole design. :idea:

Good luck with your prototype.

-Roy

Title: Re: What equipment are you currently working on?
Post by: Mariusz on 18 Jun 2009, 02:56 am
Mariesz,

Thanks for the invitation to hear your prototype bipoles but I'm on the other side of the country (Washington State) :icon_frown:.

My speakers use some sort of multicolored foam to control the backwave. It looks similar to carpet padding but much thicker.

AudioKinesis has an interesting bipole design, The Dream Weavers, that vertically offset the rear drivers from the front drivers. Hmmm... I wonder if tilting the box slightly backwards would perform the same function? I do that with my bipoles.

 Well... maybe a thread could be devoted to bipole design. :idea:

Good luck with your prototype.

-Roy


Sorry for late reply ( been a bit busy )

So you're in Washington State...  But hey, if you ever plan the trip to New York City my door is always open.

* the foam Louis uses is standard on all model (as far as I know) and its use might be related to ease of use as well as desire effect  (signature sound of Omega) it provides.
+ I use Acousta-Stuf Polyfill in my (lightly)

* AudioKinesis has reputation and well regarded designs under its belt, however my experience with his products is nonexistent. But I would like to hear them one day in the right system.

** vertically offset might be one way to go but it seems like farther modifications to my  design aren't necessary. Tilting the speakers helps a bit and should be done to suit individual taste and listening environment/listening position.
+ I found that slight tilt back works for me in my own setup.

Today I've spend the whole evening modifying new cabinet made out of Baltic Birch and thin layer of MDF.  Incorporating heavier base helped stabilizing the speaker and provide extra hight without extra long spikes. Some improvement were noticeable with new cabinet, especially the lower bass reproduction and dynamics.

(listening them sing right now)


Best
Mariusz



Title: Re: What equipment are you currently working on?
Post by: Scott F. on 20 Jun 2009, 08:36 pm
Chris (MerRev) and I have spent the last few weekends building him a pair of Lowther Open Baffles (similar to mine).

This morning I got up to the wood shop before it got too hot and made some more progress on them.

The first of the two bases nearly finished
(http://www.audiocircle.com/image.php?id=19773)

Not too bad of a corner
(http://www.audiocircle.com/image.php?id=19774)

The second base cut, fitted and ready for assembly
(http://www.audiocircle.com/image.php?id=19772)

All clamped up and nowhere to go
(http://www.audiocircle.com/image.php?id=19775)

The stanchions waiting to be assembled
(http://www.audiocircle.com/image.php?id=19776)

Fitted and ready for gluing
(http://www.audiocircle.com/image.php?id=19777)

...and this is what they will look like when they are completed (these are mine)
(http://www.audiocircle.com/image.php?id=19782)

A quick pic of my wood shop
(http://www.audiocircle.com/image.php?id=19778)

.....and of course, every shop needs tunes
(http://www.audiocircle.com/image.php?id=19780)
(http://www.audiocircle.com/image.php?id=19781)
...thats a Rotel RC 970BX pre, Rotel RB 981 amp, a SB2 driving the MHDT Constantine DAC and finally a pair of JBL 4410 Studio Monitors   :thumb:


With some luck we should have these finished off in a couple of weeks.
Title: Re: What equipment are you currently working on?
Post by: Kevin Haskins on 20 Jun 2009, 10:10 pm
Learning the art of machining the hard way.

(http://www.exodusaudio.com/images/tormach2.jpg)

(http://www.exodusaudio.com/images/tormach1.jpg).jpg"
Title: Re: What equipment are you currently working on?
Post by: Scott F. on 20 Jun 2009, 10:37 pm
(http://www.exodusaudio.com/images/tormach1.jpg)

....oooops  :duh:   :lol:
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 21 Jun 2009, 12:10 am
(http://www.audiocircle.com/image.php?id=19788)
(http://www.audiocircle.com/image.php?id=19787) (http://www.audiocircle.com/image.php?id=19786) (http://www.audiocircle.com/image.php?id=19785)

Wires
Bipolar prototypes driven with 2.5 watt amp
Title: Re: What equipment are you currently working on?
Post by: JoshK on 21 Jun 2009, 12:28 am
Excellent!  I love seeing work in progress.   Nice shop Scott, I'm jealous of the space you have.  In my shop all the machines are on wheels and you have to wheel them one at a time into the work area.

Mariusz, I've been wanting to learn wood burner.  I have a project that needs some decaling.  Looks great.
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 21 Jun 2009, 12:36 am
Excellent!  I love seeing work in progress.   Nice shop Scott, I'm jealous of the space you have.  In my shop all the machines are on wheels and you have to wheel them one at a time into the work area.

Mariusz, I've been wanting to learn wood burner.  I have a project that needs some decaling.  Looks great.

I can loan you my to practice!

Mariusz :thumb:
Title: Re: What equipment are you currently working on?
Post by: Scott F. on 21 Jun 2009, 04:22 am
Nice shop Scott, I'm jealous of the space you have.  In my shop all the machines are on wheels and you have to wheel them one at a time into the work area.

Thanks Josh. I know exactly how you feel. My old shop was the same way yours is now. A couple of years ago I decided to convert my barn (25x35) into a wood shop. Later this summer I'll get the Heat and AC installed. Then I'll get my air compressor moved up there and pipe both floors. I plan on using the hayloft as a spray booth. Since I'll be spraying finishes, I need some temperature and humidity control.

I'm trying to get Chris' speakers done fairly quick because we're planning on a pretty fair sized addition to our house later this year. Part of it is going to be a new kitchen. In turn I'm/we're going to build the kitchen and bathroom cabinets up there. That should save us at least 20-30k alone not to mention doing a fair amount of our own mill work.

It will be a fair amount of work but it should be fun.
Title: Re: What equipment are you currently working on?
Post by: MerRev on 21 Jun 2009, 04:13 pm
I'll be the lucky recipient to all the pics Scott posted above and I have to say a huge public thank you to Scott Faller for all of his help on this time consuming project.  :thumb: His converted barn now serves as a workshop and his investment in quality tools and equipment really made this build considerably easier.  Also, having tunes that could blast over a router or running saw kept our spirits up. :drums: 
We're in the home stretch here and I think I owe it to Scott to really finish them with a nice stain.  Scott's meticulous attention to detail and patience throughout the build surprised me a bit but I'm so much happier we put in the time and effort and am really proud of the almost completed open baffle Lowther project.  I'm also glad Scott took a few pics to document the journey. 8)

The version we are working on will use the Alnico based Lowther PM6A which I know Scott likes as well and both Jon Ver Halen and Nelson Pass have really good things to say about it too.  The plan thus far includes driving them with a 2A3 amp and crossing them over to a pair of Altec Valencia's minus the horn loaded tweeter. 

                                          -Chris
Title: Re: What equipment are you currently working on?
Post by: lonewolfny42 on 24 Jun 2009, 05:34 am
I'll be the lucky recipient to all the pics Scott posted above and I have to say a huge public thank you to Scott Faller for all of his help on this time consuming project.  :thumb: His converted barn now serves as a workshop and his investment in quality tools and equipment really made this build considerably easier.  Also, having tunes that could blast over a router or running saw kept our spirits up. :drums: 
We're in the home stretch here and I think I owe it to Scott to really finish them with a nice stain.  Scott's meticulous attention to detail and patience throughout the build surprised me a bit but I'm so much happier we put in the time and effort and am really proud of the almost completed open baffle Lowther project.  I'm also glad Scott took a few pics to document the journey. 8)

The version we are working on will use the Alnico based Lowther PM6A which I know Scott likes as well and both Jon Ver Halen and Nelson Pass have really good things to say about it too.  The plan thus far includes driving them with a 2A3 amp and crossing them over to a pair of Altec Valencia's minus the horn loaded tweeter. 

                                          -Chris
Question....How thick is that Plexi-Glass ? Thanks.... :thumb:
Title: Re: What equipment are you currently working on?
Post by: MerRev on 24 Jun 2009, 01:38 pm
Hi Chris!   

The panels are 3/4" plexi but seem to weigh a ton.  I'm guessing in the neighborhood of 20-25lbs per panel.  Here's a earlier post with the adhesive backing on them and cutout without drivers which helps a bit.
 http://www.audiocircle.com/index.php?topic=62786.msg567623#msg567623 (http://www.audiocircle.com/index.php?topic=62786.msg567623#msg567623)

Also, I've been meaning to share this with you for a while.
Kathleen Edwards song "The Lone Wolf":

He was the lone wolf you could see it in his eyes
The way he held his heart the way he held his lies
Sometimes he's just show up outside on the porch
And hour at a time like a lonely whore

She was a scarecrow the way she always looked around
For something she once had and never could be found
Time was on her side but she never kept track
All the hunters came and took her memories back

Once they met inside a dirty curtained room
And the rain fell down hard that day onto the tin roof
She said "I've seen you before, I've been looking for you
Better keep your heart close hunters are coming for you"
He said "I've seen them before and I always get away
Cuz you will never stop looking and I will never stay"

The lone wolf kissed her mouth like so many before
Scarecrow closed her eyes and then she closed the door
And the rain fell down on the tin roof when the hunters came that night
Stole all of her memories killed the wolf and all his lies.


                                  -Chris
Title: Re: What equipment are you currently working on?
Post by: lonewolfny42 on 25 Jun 2009, 03:00 am
Thanks for the info Chris....good luck with the speakers...I'll watch for your listening comments. :thumb:

And....thanks for the tune.... :beer:

                 Chris
Title: Re: What equipment are you currently working on?
Post by: JoshK on 12 Jul 2009, 01:05 am
Making the baffles for my bass bins.  Whow buddy, they are big.  :o   Somehow 30" x 20" x 22" doesn't sound that big. 

Now I am thinking of flipping them so that they are 20" tall and 30" wide.  20" tall is much better for setting the abbey clone speakers on.  Otherwise the CD will be well above the listener's head.

Title: Re: What equipment are you currently working on?
Post by: Scott F. on 12 Jul 2009, 03:43 am
Well, today Chris (MerRev) finally finished up his Lowther PM6A open baffles. Chris took them back to his place to stain and do the final assembly. Here is a pic of the baffles completed. The acrylic panel still has the protective paper covering on it.

(http://www.audiocircle.com/image.php?id=20334)

They turned out pretty good. After seeing how well the bases turned out, I wish I had done mine out of oak.
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 31 Jul 2009, 02:03 am
Trying to build some full range (or almost) speakers for my listening room.
Upper limitation of these 15" drivers is about 15K. Not that everyone can hear beyond that point but just because I can, super-tweeter will be implemented and crossed/cut at 7-8K (8-33K)for extra air and resolution.(attenuator at the back of the ST housing).(30Hz-33KHz)
Drivers are quite nice and presentation is definitely different then most 8" drivers I've used.
Hard to go back to smaller drivers if I must be honest. 
Using this driver in OB was fun and it might be the solution for those on the budget, however. If you care about those information below 70Hz or despite using a sub in your system, OB might not float your boat. What you get tho is lock of box coloration and purity of the driver itself. I would imagine these 15 inchers in OB with quality OB subs for amazing bang for the buck system.
If not, ......... box is your only choice to get some earth shaking bass out of them.
There is some controversy about the proper box for these drivers so I decided to build what I feel is right for my taste and my ROOM.
Here is the scoop:
(http://www.audiocircle.com/image.php?id=20781)

Cheers
Mariusz :thumb:
Title: Re: What equipment are you currently working on?
Post by: Mariusz on 2 Aug 2009, 12:44 am
I'll upload "work in progress" pictures of this design and more in depth information and thoughts.

(http://www.audiocircle.com/image.php?id=20828)

It should match my DIY Red Devil turntable.
(http://www.audiocircle.com/image.php?id=19280)


Mariusz :thumb:
Title: Re: What equipment are you currently working on?
Post by: Berndt on 2 Aug 2009, 05:42 am
Learning the art of machining the hard way.



(http://www.exodusaudio.com/images/tormach1.jpg).jpg"

It is a drag when you just busted your last 250$ dataflute endmill and have to slow everything down to make a brand x cutter work.
Good luck Kevin, maybe we could consider a machining circle?
Title: Re: What equipment are you currently working on?
Post by: JoshK on 26 Aug 2009, 01:49 am
Started gluing up my bins today.  One is all clamped up.  Biscuit jointers rock!  It was SO much easier to put a big box together while keeping everything mutual orthogonal with the biscuit joints.  Not to mention they make the joints stronger.

The baffle hasn't been glued on, that will be after the driver hole is machined and the oak cross braces have been added.  Babies are going to be HEAVY!  Glad I used 1.5" baltic birch on all sides but the baffle (2.25" BB/MDF sandwich) as the BB is lighter, although still heavy.

Wife commented that she saw my boxes and they are huge.   :icon_lol:  Her reaction was better than I thought it would be.  It wasn't a "no well in hell." 

Title: Re: What equipment are you currently working on?
Post by: JoshK on 27 Aug 2009, 01:42 am
Not very exciting, but work in progress...

(http://www.audiocircle.com/image.php?id=21464)
Title: Re: What equipment are you currently working on?
Post by: JoshK on 30 Aug 2009, 11:15 pm
Dry fitting the baffle, threw in a woofer to see how it is gonna look.

(http://www.audiocircle.com/image.php?id=21594)

(http://www.audiocircle.com/image.php?id=21595)
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 31 Aug 2009, 02:23 am
Very nice Josh, those are gonna move some air for sure.
Title: Re: What equipment are you currently working on?
Post by: 56oval on 31 Aug 2009, 04:00 am
Hi Josh
Looking good is this the 15"AE .

Cheers
Title: Re: What equipment are you currently working on?
Post by: JoshK on 31 Aug 2009, 01:16 pm
Yeah it is a AE (Lambda) TD15X.  I have passive radiators ordered but still haven't heard word that they are shipping.  I'll probably try the boxes sealed and then with PRs. 

They should move some air alright.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 10 Sep 2009, 01:36 am
I nick-named the above bass bins, Donner (http://en.wikipedia.org/wiki/Donner).  Thor has been done before.   I received the PRs and cut the holes today.  I bought the 2" OC 703 to line the cabinets with.  Inching closer, little by little.
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 10 Sep 2009, 11:14 am
I am finally doing something about the bare MDF on my Abbeys. Nothing fancy as I am not a particularly good wood worker. I'm going to wrap them in glorious vinyl that looks sort of like oak and paint the front panel and compound corners with black satin. I have filled and sanded the holes and they seem pretty smooth. I've put a couple of coats of primer on the front and when sanded to 400 grit they feel smooth, I think one more coat and sanding and I'll try and hit them with some paint. They likely won't win any awards but they should look a lot better than they have for the last 8 months.

I'm trying to get this done before winter and since I spent most of the summer unable to walk from foot surgery I'm trying to cram some projects in the next few weeks, at least anything that requires warmth and fresh air.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 11 Sep 2009, 02:48 am
I am finally doing something about the bare MDF on my Abbeys. Nothing fancy as I am not a particularly good wood worker. I'm going to wrap them in glorious vinyl that looks sort of like oak and paint the front panel and compound corners with black satin. I have filled and sanded the holes and they seem pretty smooth. I've put a couple of coats of primer on the front and when sanded to 400 grit they feel smooth, I think one more coat and sanding and I'll try and hit them with some paint. They likely won't win any awards but they should look a lot better than they have for the last 8 months.

I'm trying to get this done before winter and since I spent most of the summer unable to walk from foot surgery I'm trying to cram some projects in the next few weeks, at least anything that requires warmth and fresh air.

To date, finishing is my least favorite part of DIY.  Its probably cause I am not yet good at it and therefore it doesn't go smoothly.  I am taking my dear sweet time with my MT portion, learning as I go.  I picked up some single tube glazing putty yesterday, thanks to Dr. Geddes's thread.

I put in braces and lined the bass bins with the 703 and made up internal wiring harnesses today.  All this takes much more time than it looks.  Of course, I fiddle about.   Oh yeah, and I drilled holes for all the speakers to mount.  I countersunk the hurricane nuts and chamfered the back.  Drill presses are nice for adding these nice touches.  I also countersunk the speakon connector.  I am going to sink hurricane nuts for the feet, so that they can be removed/replaced. 

I went a little nutty professor with my bracing.  Its all done in golden ratio bi-sections.  I braced all three axes and all three are mutally golden ratio bisectors of the panels in both dimensions.  Basically, you draw a diagonal on the wall you join to.  Measure this diagonal, call it D, divide by 2.618 (1+phi).  Measure and mark this distance on the diagonal.  This point bisects both sides of the panel at golden ratios. 

Title: Re: What equipment are you currently working on?
Post by: 56oval on 11 Sep 2009, 03:19 am
Well the cabinets are finally getting CNC'ed it wasn't worth me buying any wood working tool's .
Andrew who is CNCing the cab's for me , own's his own speaker building company http://www.aslanacoustics.com.au/   and bought himself a cnc router .I asked him if he would be interested in one off projects and he said send me a drawing ,so here is the job.
This is a google render I done
(http://www.audiocircle.com/image.php?id=21936)
(http://www.audiocircle.com/image.php?id=21935)

The front baffle will be done in 20mm thick 5086 alloy with the ply having a inner & out alloy skin skin,the dowels are 10mm alloy rod spaced 50mm apart .

Cheers

Mal
Title: DIY Pass Labs Aleph J and Aleph J-X clones
Post by: TomS on 11 Sep 2009, 07:21 pm
Just started another Pass DIY project and have been accumulating parts.  This is based on a new PCB Peter Daniel just did which allows either an Aleph J as stereo (4 MOSFETS per ch) or pairing up 2 boards with a single daughter board for an Aleph J-X monoblock version (8 MOSFETS per monoblock).  I am building up the J first, then perhaps try the X version since I liked Zybar's AJ-X a lot on my CS2 compression drivers (now gone).  While I'm told the DIY AJ-X isn't quite up to the sweet Pass XA30.5 sonically, it should be a fun effort using bare hands and modest cash.  Still a lot of heavy metal in this one though.  Power supply PCB's are CViller's CRC with Panasonic TSHA 22k uf x 8 each,  Mills resistors, IXYS VBE 55-06NO7 FRED bridges.  They also have the option to go offboard CLC if you so desire and have the iron and space.  Transformers are still TBD as I didn't really want to tear my F4's or F5 apart just yet to scavenge those.  Using Peter's F4, F5, and AJ boards' hole spacing, these sinks and PS will be modular such that it is a very simple swap of the signal boards with just a few screws on the MOSFETs, 2 signal/3 power/2 output wires, and quick re-bias.  Fortunately, the power supplies are common to all of the FirstWatt designs.  And yes, those 7-legged critters are real live 2SJ109's  :green:

Thank you again to NP for sharing this design with the solder slingers (for personal use only!).

Tom

(http://www.audiocircle.com/image.php?id=21949)
(http://www.audiocircle.com/image.php?id=21950)
(http://www.audiocircle.com/image.php?id=21951)
Title: Re: What equipment are you currently working on?
Post by: JoshK on 11 Sep 2009, 07:45 pm
Looks cool Tom.

Title: Re: What equipment are you currently working on?
Post by: JoshK on 11 Sep 2009, 07:57 pm
Some progress pictures...

(http://www.audiocircle.com/image.php?id=21952)
(http://www.audiocircle.com/image.php?id=21953)
(http://www.audiocircle.com/image.php?id=21955)
Title: Re: What equipment are you currently working on?
Post by: 56oval on 12 Sep 2009, 01:28 am
Hi Josh
Which cabinets are these for and what drivers .

Cheers
Title: Re: What equipment are you currently working on?
Post by: JoshK on 12 Sep 2009, 02:06 am
Yeah it is a AE (Lambda) TD15X.  I have passive radiators ordered but still haven't heard word that they are shipping.  I'll probably try the boxes sealed and then with PRs. 

They should move some air alright.

These ones.  AE TD15Xs with two PR15-1400gs each.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 12 Sep 2009, 03:58 pm
In case scale isn't obvious, those are 12" x 12" tiles.
Title: Re: What equipment are you currently working on?
Post by: 56oval on 25 Sep 2009, 05:58 pm
Here's a couple pic's of the alloy front baffle's .

(http://www.audiocircle.com/image.php?id=22270)
(http://www.audiocircle.com/image.php?id=22269)

Cheers
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 27 Sep 2009, 02:42 am
Those baffles are very cool. Should make for a nice dead structure.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 27 Sep 2009, 02:48 am
Finally put a finish on my Abbeys, not going to win any awards but it's much better than raw MDF. I painted the front satin black and clear coated that. The rest of the cabinet is wrapped in state of the art vinyl from Parts Express.  :roll: They look better than I expected and pretty good when the lights are off. ;)

While I had them apart I lined the inside of the cabinet with No-Rez from GR Research and also changed out one crosssover cap as Earl had revised the crossover slightly from when I first built them. I have to say the results are more than I expected. The addition of the No-Rez seems to have freed the music from the speakers a bit, likely the cabinets are quieter.

I'll try and snap a photo or two tomorrow, too tired tonight to do anything but listen to music and check out AC.

mike
Title: Re: What equipment are you currently working on?
Post by: 56oval on 27 Sep 2009, 03:32 am
Finally put a finish on my Abbeys, not going to win any awards but it's much better than raw MDF. I painted the front satin black and clear coated that. The rest of the cabinet is wrapped in state of the art vinyl from Parts Express.  :roll: They look better than I expected and pretty good when the lights are off. ;)

While I had them apart I lined the inside of the cabinet with No-Rez from GR Research and also changed out one crosssover cap as Earl had revised the crossover slightly from when I first built them. I have to say the results are more than I expected. The addition of the No-Rez seems to have freed the music from the speakers a bit, likely the cabinets are quieter.

I'll try and snap a photo or two tomorrow, too tired tonight to do anything but listen to music and check out AC.

mike
Hi Mike
I was looking at getting Dr Earl's speaker kit ,but the Oz dollars went south really quick and put a stop to it ,maybe next year a Summa kit would be cool .

He's a pick of the striplam's stack with the baffle
(http://www.audiocircle.com/image.php?id=22288)


Cheers
Mal
Title: Re: What equipment are you currently working on?
Post by: JoshK on 27 Sep 2009, 06:56 pm
Those are cool baffles!

Yesterday I did some spot glazing and primer coats on my MT baffles.  One baffle is done to the point of ready for sanding and painting, the other is close. 

I need to get some wood filler for the bins.  I also don't have quite enough veneer to cover them.  I need to order some more.

Title: Re: What equipment are you currently working on?
Post by: poseidonsvoice on 1 Oct 2009, 10:32 pm

Quote
Hi Mike
I was looking at getting Dr Earl's speaker kit ,but the Oz dollars went south really quick and put a stop to it ,maybe next year a Summa kit would be cool .

He's a pick of the striplam's stack with the baffle
(http://www.audiocircle.com/image.php?id=22288)
Cheers
Mal


Looks like you are going for that 'Magico' look. Very cool.

Anand.
Title: Re: What equipment are you currently working on?
Post by: 56oval on 3 Oct 2009, 02:45 am

Quote
Hi Mike
I was looking at getting Dr Earl's speaker kit ,but the Oz dollars went south really quick and put a stop to it ,maybe next year a Summa kit would be cool .

He's a pick of the striplam's stack with the baffle
(http://www.audiocircle.com/image.php?id=22288)
Cheers
Mal


Looks like you are going for that 'Magico' look. Very cool.


Anand.

Hi Anand

Cheers mate.

When the cab's are finished you won't end up seeing the ply . The striplam construction ended up being easier to make the cabinet's in the shape I wanted than using  high quality bendy ply that could be bent in a small radius .

Cheers

Title: Re: What equipment are you currently working on?
Post by: nullspace on 8 Oct 2009, 09:18 pm
(http://www.audiocircle.com/image.php?id=22584)
(http://www.audiocircle.com/image.php?id=22585)

I've been working on a 6EW7->2A3 pushpull amp for a while, so here's an update.

The first jpg is the signal portion for one channel and the other jpg is the power supply for one channel. Here (http://nullspace.us/2a3pp/6EW7_2A3.gif) is a schematic if you're interested.

It's pretty straightforward: input transformer-buffered volume control (Penny&Giles RF11 in this instance), 6EW7 twin triode doing both input and driver duty with the little triode DC-coupled to the big triode, MQ autoformer as phase splitter, and 2A3 parafeed PP finals, with cathode biasing all around. The DC side of things is full-wave rectification with 6CJ3 TV damper diodes into a choke-input filter.

Results are preliminary, but suffice to say it's a much different amplifier than the 27 preamp/ 56->45 SE amp combination I've been living with for the last year or so. Very cliche, but with the PP amp I'm hearing all kinds of details/ articulation that were lost in the previous setup. But at the same time, I spend a whole lot less time singing along (which may be a good thing) as there seems to be less emotional content. If I could just get the transparancy of the PP amp along with the emotional connectedness of the SE amp I'd be all set...

Parafeed for SE amps is pretty well documented, but less so for PP amps; I've only seen a couple of amps that use it, none commercially. Here (http://www.audioasylum.com/forums/magnequest/messages/1466.html) is a note from Mike @ Magnequest on why parafeed might be beneficial for PP amps. I have every intention of trying both series and parallel-feed, and attempted to wire things such that it wouldn't be too onerous to try.

Regards,
John
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 8 Oct 2009, 09:40 pm
Doing up a DIY Schroeder tonearm... more cost effective to build 3... piece price of the parts vs. setup and tooling make the first one pricey, but the 2nd and 3rd a helluva lot less ex$pensive
Some of the parts are still 30 days out.....lead times don't ya know  :cry:

(http://www.audiocircle.com/image.php?id=22586)(http://www.audiocircle.com/image.php?id=22587)
Title: Re: What equipment are you currently working on?
Post by: nullspace on 8 Oct 2009, 09:48 pm
Wow, that's very nice, Jeff.

You've been participating in the DIY Schroeder thread at diyAudio, right (it's been a while since I checked it out)? That thread is a classic example of how unbelievably awesome some manufacturers are in supporting the DIY community, IMO.

Regards,
John
Title: Re: What equipment are you currently working on?
Post by: JoshK on 26 Oct 2009, 01:36 pm
That DIY schroeder arm is inspiring.  Where do you get the machining done?

I've been veneering my bins.  Its very slow going, as I usually do one side at a time, which is usually one side every other day.  I have one 2/3 done and the other 1/3 done. 

On another note, I started constructing my First Watt clone chassiss.  I've had some Conrad heatsinks for a while now, and I ordered some aluminum to make them into chassis.  Gordy had given me a tap and die set some time ago so I am going to try to tap the heatsinks and mount the aluminum plates directly. 

The faceplate is 1/2" thick aluminum.  I was a little concerned that it would be hard to cut as I didn't order it precut.  However, I bought a non-ferrous metal blade for my miter saw and as long as you went slow it cuts like butter.  It didn't even make a lot of noise like I expected.

When I get it all tapped and cut, I am going to look up a powder coating/anodizer to finish them.  Anyone know of a good resource, preferrably local to the NNJ/NY area?



Title: Re: What equipment are you currently working on?
Post by: BobM on 26 Oct 2009, 02:09 pm
Just finished building a Peter Millet "Mini-Max" headphone amplifier to use with my HD-600's. A nice, compact and inexpensive tube-hybrid design. It's got 25 hours on it so far and has started to open up nicely. No trace of grain or distortions with good air and deep punchy bass.

I needed to build something after my Sony DVD player crapped out and I bought a new Ayre CX7e CD player (no more headphone jack). This solution now lets me also listen to records on the headphones too!

http://www.diyforums.org/MiniMAX/MiniMAXoverview.php (http://www.diyforums.org/MiniMAX/MiniMAXoverview.php)
Title: Re: What equipment are you currently working on?
Post by: jrebman on 26 Oct 2009, 03:27 pm
Hi Bob,

I'm 99% done with mine too.  Can I contact you offline as I'm blind and my only question left is where to solder the connections on the board to the tube bias test points.

-- Jim
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 26 Oct 2009, 10:52 pm
The flat pattern pieces are being sourced from Front Panel Express, they work with 6mm, 8mm and 10mm thick aluminum, My pieces are 8mm thick.

THe other machined parts are being mad by eMachineshop.com. THey have a 30 working day leed time :(

JD



That DIY schroeder arm is inspiring.  Where do you get the machining done?

I've been veneering my bins.  Its very slow going, as I usually do one side at a time, which is usually one side every other day.  I have one 2/3 done and the other 1/3 done. 

On another note, I started constructing my First Watt clone chassiss.  I've had some Conrad heatsinks for a while now, and I ordered some aluminum to make them into chassis.  Gordy had given me a tap and die set some time ago so I am going to try to tap the heatsinks and mount the aluminum plates directly. 

The faceplate is 1/2" thick aluminum.  I was a little concerned that it would be hard to cut as I didn't order it precut.  However, I bought a non-ferrous metal blade for my miter saw and as long as you went slow it cuts like butter.  It didn't even make a lot of noise like I expected.

When I get it all tapped and cut, I am going to look up a powder coating/anodizer to finish them.  Anyone know of a good resource, preferrably local to the NNJ/NY area?
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 1 Nov 2009, 10:21 pm
More parts coming in... partial assemblies built up, still waiting for more parts. Also a pic of the turnatable one of the arms will be mounted on.

Jeff(http://www.audiocircle.com/image.php?id=23363)(http://www.audiocircle.com/image.php?id=23364)(http://www.audiocircle.com/image.php?id=23365)(http://www.audiocircle.com/image.php?id=23366)(http://www.audiocircle.com/image.php?id=23367)(http://www.audiocircle.com/image.php?id=23368)(http://www.audiocircle.com/image.php?id=23369)(http://www.audiocircle.com/image.php?id=23370)(http://www.audiocircle.com/image.php?id=23371)
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 2 Nov 2009, 02:05 am
That is going to be one sweet setup. Are the copper colored pieces solid copper or just plated?
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 2 Nov 2009, 02:14 am
I have been slowly, ever so slowly, working on a Buffalo DAC for a good friend of mine. We picked up a couple of the first run of Buffalo boards with the 9008 chip, prior to ESS releasing the Sabre 9018 chip. We were able to score a couple of the 9018 chips, which I will be transplanting to the original boards soon.

He wanted a tube output stage and I went through several iterations before I had something that seemed like it would work well. I ended up using a 12B4 with a Pimm CCS and taking the output from the mu follower connection. Power supply for the tube section is a Tubecad dual supply configured for 12.3V and 300V for the B+.

I finally had some time today and drilled a lot of holes to mount everything to the chassis. Still waiting for the transformer for the tube section but everything else is more or less ready to wire up. Still have to drill the front and back panels but that will go quickly.

Couple of pics.

(http://www.audiocircle.com/image.php?id=23381)

(http://www.audiocircle.com/image.php?id=23382)
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 2 Nov 2009, 03:33 am
Solid.  Copper 101 alloy.

JD

That is going to be one sweet setup. Are the copper colored pieces solid copper or just plated?
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 2 Nov 2009, 03:31 pm
Very cool. I love the color and of course a bit more mass than brass.  :thumb:

Solid.  Copper 101 alloy.
Title: Re: What equipment are you currently working on?
Post by: JoshK on 2 Nov 2009, 03:48 pm
Truly drool worthy, Jeff.   :drool:

Like the copper on silver too.

Nice project Mike!  Keep us up to date.

Over the weekend, I did some more work on veneering and trimming.  I had some house stuff to do so I didn't finish.

However, I started the audio cabinet project.  I gutted the dresser and ordered the 80/20 parts.  Its going to be interesting if it works out nice.  Hopefully it will give some folks ideas on other ways to make a LR system WAF friendly. 

I cut all the drawer faces off.  They will be mounted on a plywood backer that will act as doors to the cabinet.  The sides and top are left in tact and the back thin plywood was removed to gain access to the back. 

The dresser was pretty scratched up so it will get painted black with the detail done in silver by my wife.

Title: Re: What equipment are you currently working on?
Post by: mackortoyota on 20 Nov 2009, 11:58 pm
I rebuilt a 1970's multimeter. New power supply (one of the previous owners pulled it out for some reason), cleaned the switch contacts, calibrated it, and oiled the gearbox (it has an ignition coil tester, but uses a mechanical inverter). One of the rotary switches I had to completely strip down, and the spark cap for the coil tester needed cleaned and adjusted. Stevens ST-70. 5" gauge, lots of rotary switches, and a 5w ohmite wire-wound pot, all for 20 bucks.
Title: Re: What equipment are you currently working on?
Post by: nullspace on 11 Dec 2009, 05:25 pm
I built a prototype to see if I could pull together a fullrange open baffle speaker. It's a 2.5way -- mids and treble are as before, Beyma CP380M + AH!1000 conical horn and ToneTubby 12" AlNiCo. The .5 is now a 4x Eminence Kappa-12A. Initial listening impressions are generally positive, and I'll be pulling out the measurement gear later today. I'm hoping for an f3 of around 40hz; we'll see...

Regards,
John

(http://www.audiocircle.com/image.php?id=24448)
Title: Re: What equipment are you currently working on?
Post by: nullspace on 11 Dec 2009, 09:57 pm
Ran the freq. measurements. Strong down to 50hz, then rolls off very quickly thereafter. A little shy of expectations, but hopefully after the Eminence drivers break in a bit the suspensions will loosen up and Fs will drop closer to the book value of 45hz.

With such a larger baffle than I had previously been using, the ToneTubby now reaches <200hz. Consequently, I'm crossing over the .5 much lower, more than an octave lower. This is as I had planned, but I had not expected that with just one TT now covering 200-400hz, the mids are quite a bit more clear. A nice bonus.
Title: Re: What equipment are you currently working on?
Post by: nullspace on 12 Dec 2009, 12:12 am
Despite the loss of low-end extension, one reason for trying out fullrange speakers, rather than sticking with my previous arrangement of main baffles plus SS-driven helper (sub)woofer baffles, is that I like to build to amplifiers and the previous setup, to me, wasn't particularly well-suited to that endeavor for a couple of reasons.

For this go-around, I ws looking for something that was more-or-less fullrange and would be amenable to being driven by the type of amps I like to build -- low-powered, no feedback/ low-dampening DHT amps. So, here's what we get: a high-sensitivity, I'm guessing 97-98dB since that's about what the ToneTubby T/S #'s say it is and there isn't much to drag it down, and a benign load. I think the impedence generally looks pretty good, and should be a good match. It sounds that way so far, anyways...

Regards,
John

(http://www.audiocircle.com/image.php?id=24461)
Title: Re: What equipment are you currently working on?
Post by: nullspace on 12 Dec 2009, 12:37 am
In case anyone would like to see the crossover. Really, it's not as bad as it looks...

(http://www.audiocircle.com/image.php?id=24463)
Title: Re: What equipment are you currently working on?
Post by: JoshK on 12 Dec 2009, 12:59 am
Very cool.  I understand the desire to want to run full range one amp for amp comparison.  Looks quite good. 

Do you find the bass keeps up with the highs in terms of perceived speed, attack and dynamics?
Title: Re: What equipment are you currently working on?
Post by: nullspace on 12 Dec 2009, 01:34 am
The bass certainly keeps up. Part of the reason for choosing the Kappa-12A is that they have no need for dampening from the amp -- the book value for qts is .27. Then, I can use the series attenuation needed without worrying about loose, flabby bass. Nothing new here, obviously, just vamping off the Nelson Pass whitepaper on transconductance amps w/ low-Q drivers.

I would've liked to use 15" drivers, but I couldn't fit four of them on a baffle and keep the mid- and treble- at a reasonable height. 

John
Title: Re: What equipment are you currently working on?
Post by: JoshK on 12 Dec 2009, 01:47 am
So far, to date, I've heard two open baffle + hi eff implementations and they were both so-so.  It very well could have had to do with the implementation, but they were a little slow sounding in the bass and like they were being held back; clean though and not boxy.  The first was high Qts bass drivers, the second, I don't know.    That is why I asked.

Title: Re: What equipment are you currently working on?
Post by: nullspace on 12 Dec 2009, 02:39 am
Sure. They do integrate quite well with the mids, and they are definitely more taut than the OB15 I have. But, that could also be because that the Eminence are a bit more rolled-off than the AE drivers, lending to the sense of lean-ness in the bass.
Title: Re: What equipment are you currently working on?
Post by: nullspace on 12 Dec 2009, 07:46 pm
Hey Josh,

I had another listen today, with the intent of fleshing out what you were talking about. I EQ'd up the low end via Foobar so that the freq. response would be a bit bass-heavy, then listened to some Beck ('Guero' and 'Sea Change'). Certainly the bass overwhelmed the small room I sit in, but it was still very tight and transitioned nicely to the mids. I don't want to say 'seamlessly' because that word gets thrown around too easily, but the integration is definitely one of the high points. Without the EQ, the bass was really excellent, if a bit light.

Now if only the response didn't drop-off a cliff under 45hz or so. I'm a little suprised by how much I miss that last octave, especially considering that the OB15 only covered down to 30hz. I could get one of those GR-Research servo subs, but with two huge (they're 36"Wx39"H btw) panels should I really have to? A task for another day.

Regards,
John
Title: Re: What equipment are you currently working on?
Post by: JoshK on 12 Dec 2009, 07:59 pm
Thanks John.  I like to say I try to keep an open mind. 

A couple years ago, I was sure this was the direction I wanted to go (OB + HE) but I changed my mind due to concerns that it wouldn't work well in my room, where the best listening setup is on the long wall and sitting only 9-10 ft back.  I think there wouldn't be enough distance from the back wall in this position.  If I did it the other way, it would likely work ideal but that is an awkward living room setup and I have to compromise with the lady.

So I change my direction some.  In this time, I did get to hear two such setups and wasn't really overwhelmed as much as I thought I would be, so I was trying to see if it was those setups or the format.  I am not trying to change your opinion at all.

Its unforunate just how long the wave lengths get at LF.  It really makes for huge OBs or big HE bass boxes.  No way to cheat the physics.
Title: Re: What equipment are you currently working on?
Post by: nullspace on 12 Dec 2009, 08:17 pm
I am not trying to change your opinion at all.

I didn't think that you were; I'm hoping just to be able to throw out another data point.

At times, I find myself thinking some of the same things, as much as I like open baffles and find aspects of them wonderful, there are some quite substantial tradeoffs. I spent the time I was walking the dog this afternoon wondering about Gary Pimm-style cardiod speakers...

By the way, how are your amps breaking in?

John
Title: Re: What equipment are you currently working on?
Post by: BobM on 13 Dec 2009, 03:24 pm
Currently burning in a pair of Russian .1uF Teflon caps (those big suka's) to use in my soon to be built Hagerman Piccolo step-up head amp. Parts are on the way from Mouser and Digikey. The only upgrades I'm making to it are using Vishay resistors, these teflon caps, and adding some extra capacitance to the battery power supply section (which usually helps to increase dynamics in my experience).
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 13 Dec 2009, 05:58 pm
Working on hacking the I2S signal out of a m2tech hiFace to feed my 1st gen buffalo dac but with the 32bit ESS9018 chip. The bits are mostly done, still have to assemble and test it all and hope it works.  :dance:
Title: Re: What equipment are you currently working on?
Post by: JoshK on 15 Dec 2009, 02:44 pm
Besides finishing up (pun) my bass bins, I have been working on a pair of amp chassis for Pass/First Watt clones.  I bought a quad of Conrad heatsinks way back when in a diyA group buy.  I have been collecting Peter Daniel boards (same size from board to board = reuseable setup). 

I intend to build the power supply and probably an Aleph J clone first.  Then I can experiment with the others pretty easily by swapping the boards (hopefully). 

I got a chance to practice tapping last night.  So far so good.  I used the 1/2" thick faceplate's holes as a template to ensure my taps were perpendicular. 

Tips I learned regarding tapping:
#1) use lubricant. It makes it a lot easier and helps you ensure you are staying aligned, as you can just feel it much better. (I bought aluminum lubricant, but I'm told alcohol works just as well).
#2)  in blind holes use a bottoming type tap.  Standard taps don't get the threads deep enough.
#3)  some sort of guide template helps you stay straight.
#4)  the spiral fluted taps are really slick (I bought mine on enco.com).  They push the chards up and out as you tap. 
Title: Re: What equipment are you currently working on?
Post by: jules on 2 Jan 2010, 11:51 pm
A useful trick I've discovered for using taps:

If you've got a drill press, insert the tap in the drill chuck, use the press to apply light pressure and manually wind the tap in to the point where resistance suggests you need to stop [err yes, a presumption here  :)]. After that, release the tap from the chuck while holding the press down. At this point the tap is far enough in to establish that it will stay perpendicular and in addition, the "press" start eliminates the uncertain feel you normally get. I've just done 30 or 40 taps into aluminium this way and it's much easier.

I used kerosene as a lubricant. It's ok and wouldn't evaporate quite as readily as alcohol.

Jules
Title: Re: What equipment are you currently working on?
Post by: Berndt on 3 Jan 2010, 03:26 am
As a machinist I would like to suggest wd40 for an aluminum taping fluid. Available and fairly harmless.
I would also suggest utilizing form taps which do not cut a chip, rather they form the material into it's thread shape.
You can make taping jigs out of a pc of 2x4 or plexy, just drill a clearance hole.
I use a cordless drill on slow to power tap, but would suggest this only on sizes over 1/4".
I can see that I would be more careful if an edm tap burner wasn't sitting at work.
If anyone is DIY'ing in the bay area and needs machinist help drop me a pm.
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 3 Jan 2010, 04:55 am
I had a hell of a time with my first go at tapping.  I do tend to go too fast with everything so I did snap a few taps.  My Zv9 does have a broken tap in it.  I used wd40 as a lube.  The guide idea is a great one.
Title: Re: What equipment are you currently working on?
Post by: nullspace on 3 Jan 2010, 05:04 pm
As a machinist...
If anyone is DIY'ing in the bay area and needs machinist help drop me a pm.

A machinist, you say? I'm in need of some Eimac HR1 grid/anode connectors, and they are unobtanium on the open market -- over the past three or four years I've gathered precisely two. So, I'm starting to look at getting them made. The jpg below is of the HR2, which is physically very similar. The HR1 is 11/16" long,  1/2" diameter, with a .052" diameter hole running the length. Would these be doable? Any idea what material would be best? Copper is appealing, but I suppose it would need to be plated and I don't have any idea how difficult that would be.

Regards,
John
(http://www.surplussales.com/Images/TubeSockets-Accessories/ChimneyPlateCaps/TK45.jpg)
Title: Re: What equipment are you currently working on?
Post by: ebag4 on 3 Jan 2010, 06:03 pm
I had forgotten about this circle or I would have posted here earlier.  I recently finished a pair of GR Research N3s for my sister, this is what I posted in the GR circle:

"I bought the N3 kit fom Danny shortly after they became available.  I worked on them throughout the year off and on, recently when I finally had a decent block of time I worked to finish them.  These are for my sister to replace her worn out B**e 301s.  I haven't had much time to listen but what I have heard so far is very good, although it is evident some break-in is required (they have only been playing for a couple of hours).  Playing some AC DC at decent volumes has already started to improve the bass response.  There are more similarities than differences to the sound of my OBs built with the MTM section of Danny's OB5.  Anyway, without further adieu, here they are!  BTW, Any attempted similarities to the asthetic of Jim Salk's Song Towers is purely intentional!  Sorry Jim, please remember that imitation is the sincerest form of flattery.

(http://www.audiocircle.com/image.php?id=24820)
(http://www.audiocircle.com/image.php?id=24818)
(http://www.audiocircle.com/image.php?id=24821)
(http://www.audiocircle.com/image.php?id=24819)"

Sorry guys, I didn't take any pics during the build, there was nothing really unique, different or significant to document.  I am pretty happy with the way they turned out, my sister is very happy with them.

Best,
Ed


 
Title: Re: What equipment are you currently working on?
Post by: JoshK on 3 Jan 2010, 11:37 pm
A machinist, you say? I'm in need of some Eimac HR1 grid/anode connectors, and they are unobtanium on the open market -- over the past three or four years I've gathered precisely two. So, I'm starting to look at getting them made.

Another option is http://www.emachineshop.com/
Title: Re: What equipment are you currently working on?
Post by: nullspace on 4 Jan 2010, 12:46 am
Thanks for that Josh. Have you ever used them?

John
Title: Re: What equipment are you currently working on?
Post by: JoshK on 4 Jan 2010, 02:38 am
No, I just saw that suggestion on a diy forum recently.  Can't remember where. 

Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 4 Jan 2010, 09:40 pm
Emachineshop.com
They supply the software and you do the drawings and submit them online. You get to choose the materials and the software gives you quotes before you commit. The are not inexpensive for one or two of a part as most of the costs involve setup. But when you get over 5 pieces, the cost per part becomes reasonable.

I've used them to make some parts for my Schroeder clone tonearm.
here's some links to my gallery where I have some pics:

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=2506
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=2296

JD


Title: Re: What equipment are you currently working on?
Post by: nullspace on 4 Jan 2010, 10:33 pm
Thanks for the feedback Jeff. It goes without saying your tonearm is a ringing endorsement...

John
Title: Re: What equipment are you currently working on?
Post by: Scott F. on 5 Jan 2010, 02:39 am
Hey Jeff,

Nice job on the arm. Question, where did you get the arm lift? Is it a current manufacture or did you harvest it from a donor table?
Title: Re: What equipment are you currently working on?
Post by: Berndt on 5 Jan 2010, 02:49 am
looks regaish
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 5 Jan 2010, 04:52 am
available as a spare from any Rega dealer. around $60 in the US



JD


Title: Re: What equipment are you currently working on?
Post by: sts9fan on 12 Jan 2010, 09:19 pm
I am putting the finishing touches on my Pearl/xono phono stage.  I will post some pictures in a bit.  I am looking forward to finishing it.
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 20 Jan 2010, 01:53 pm
Did some wiring last night.  Was not really feelin it so did not get too far.  Here is a pic of the signal cables attached to the back plate and one of the Pearl and xono boards.  I am using Dayton Low Noise Mic Cable for the signal cables with the sheild attached at both ends.

(http://www.audiocircle.com/image.php?id=25625)

(http://www.audiocircle.com/image.php?id=25626)
Title: Re: What equipment are you currently working on?
Post by: Wardsweb on 22 Jan 2010, 05:12 am
I'm in the middle of a custom EL34 amp based on a Dynaco ST-70. More or less a modern upgraded version.


(http://wardsweb.org/audio/ST70/build/st70_13.jpg)
Title: Re: What equipment are you currently working on?
Post by: Scott F. on 1 Feb 2010, 12:05 am
I picked up a dead HH Scott 299C from Thunderbrick a couple of weeks ago. I finally got around to trouble shooting it.

Come to find out the rectifier tube shot craps and took out the first dropping resistor. While I was in there, I replaced the B+ resistors on the phase splitters. They were really crispy and physically falling apart. I swapped them out with some 2 watt carbon films so I didn't change the sound of the unit (I couldn't find any NOS Allen Bradleys or Ohmites in that value).

After replacing the resistors, I brought her up on the variac really slow to reform all the caps. I replaced all the glassFETs with new ElectroHarmonix, set the DC balance and did a little bit of cleaning to the chassis along with adding a set of feet to the chassis.

Right now she's driving my Vandersteen 2Ce's in the exercise room pretty darned well. No issues at all with only 36wpc on those low(ish) efficiency speakers. Bass is decent and the tone is top notch.

The old Scott 299C is going to be a welcome addition to the other vintage gear that gets used almost daily around here.  :thumb:


....I know, I know...without pictures, it really didn't happen. I forgot to take any....but it really did happen! Honest!  :D
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 1 Feb 2010, 07:27 am
I've started to acquire parts for a new amplifier build. It will be a direct coupled EML 20B driver and an Eimac 304TL output tube. It will be using stacked power supplies.

(http://www.audiocircle.com/image.php?id=26184)

JD
Title: Re: What equipment are you currently working on?
Post by: JoshK on 1 Feb 2010, 03:38 pm
I've been reading your posts elsewhere, Jeff, very ambitious project.  I look forwards to seeing how it comes together.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: poseidonsvoice on 5 Feb 2010, 01:52 am
Ambitious is an understatement. Look at that schematic. Full wave bridge Graetz hybrid power supplies, multiple chokes, very fancy driver tube (and $$$), grid chokes, current regulated filament supplies, oil caps everywhere....whoah!

It makes my head spin! :notworthy:

As far as I'm concerned it'll take me a few years more to muster that level of courage and for now I am firmly -> :stupid:

Anand.
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 5 Feb 2010, 04:10 am
took me a few years to get to this point :)

Change output to parafeed..

(http://www.audiocircle.com/image.php?id=26341)
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 5 Feb 2010, 08:44 pm
Very very cool. Love to hear that one.  :drool:
Title: Re: What equipment are you currently working on?
Post by: jeffdavison on 7 Mar 2010, 03:09 am
Final tweak....(also started a thread on this).
Got all the parts and now time to put it together..

(http://www.diyaudio.com/forums/attachments/tubes-valves/161344d1267898079-304tl-based-class-eimac.jpg)
Title: Re: What equipment are you currently working on?
Post by: jtwrace on 7 Mar 2010, 05:19 am
I finished designing an all aluminum amp chassis that will be used for the Class D Audio amps. 

The really cool thing is that they can be used for anything that will fit into them.  I'll post some pics when I have the proto done.
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 21 Mar 2010, 12:48 pm
I spent the last couple of evenings tweaking the power supplies in my DAC. The DAC is one of the 1st gen Twisted Pear Buffalo board but I swapped out the ES9008 for the ES9018 chip. I'm using transformers for the output and feeding it via IS2 via a disassembled hiFace USB interface mounted right next to the DAC board.

Previously I was feeding the Buffalo board via a couple of LT1085 based regulators. The hiFace module had a fairly elaborate 5V supply I built that incorporated some of John Broskie's ideas on a feed-forward regulator. The overall result was quite good but I knew there was considerable room for improvement. In December I picked up some of Paul Hynes shunt regulators and they have been sitting until I finally had some time to tinker with it.

The end result is I added 6 new regulators to the DAC; a 3.3V for the clock, a 1.2v for the core voltage, 2 x 3.3v for the analog voltages, a 5V in front of the two digital regs and finally a 3.3v for the clocks in the hiFace in place of the DC-DC converter as suggested by John Keny though not a LiPo battery like he is using. The 3.3v for the hiFace is being fed by the feed-forward supply and the 2 x 3.3's for the AVCC are being fed from one of the 1085 based regs. The 5v shunt that feeds the digital is being fed by the raw 9V supply.

I have to say that so far the result are well worth the effort and expense. I spent a while listening last night and I kept wondering where the sock that was over my speakers went. I was hearing low level details in a very familiar recording that I have not heard before. The system seems faster and has better timing. I could not stop my feet from bouncing. Given that everything is brand new and none of the electrolytic caps have had a chance to form, it will be interesting to see if things change any.

Some may ask, why no photo. It's ugly, just really ugly. At least on the inside. I built it into a old Musical Fidelity A324 DAC chassis, so it looks pretty good on the outisde, but it's very busy on the inside, a result of build, change, change, change and change... so things are not as clean as if I'd started from scratch. :)

Title: Re: What equipment are you currently working on?
Post by: jrebman on 21 Mar 2010, 03:14 pm
Mike,

Sounds really nice.  Hope to hear it one of these days!

-- Jim
Title: Re: What equipment are you currently working on?
Post by: JoshK on 23 Mar 2010, 01:58 am
Right now, I am working on my room.  I need to figure out the long term placement of how I want it all to arrange.  Once I figure that out, i will set up my speakers and then try to work out acoustics.   Amps will take preference from there, and then the rest.   I have a rough idea in my head, but haven't put it together.

BTW, this is my 10,000th post...fitting it is in the lab.
Title: Re: What equipment are you currently working on?
Post by: AUDFILE74 on 23 Mar 2010, 02:23 am
I am presently getting the boards together for my integrated amp project. Input selection  and volume control will be Bent audio input selector and prm-solo kits. preamp section will be dual Pass B-1 units. amp section will be Panson audio compact series. once i get all the board together, then i have to pick caps and resistor. then i have to order trafos. goal is to have boards build by the time i can get  the trafos. want it done by october. tomorrow i order the B-1 boards. already have amp boards.
Title: Re: What equipment are you currently working on?
Post by: James Romeyn on 23 Mar 2010, 05:00 am
My pure analog Trinaural processor has 3.1 XLR and SE outputs.  The receiver employed has only SE inputs (never seen a receiver with XLR inputs).  This system (and my ears) are super sensitive to absolute phase. 

Plan is to hard wire a switchbox with four XLR plugs, a 4PDT gold contact switch, and four SE RCA outputs.  The switch will allow phase selection for all four channels (3.1).  Problem is I love Stan Warren's recipe interconnects, which are AWG12, about as flexible as suspension bridge cable.  Plan to anchor a strip of wood to the box, hot melt the AWG12 down to the lower piece of wood then sandwich the cable between an upper piece of wood screwed to the lower piece.  Only one or two strands of the AWG12 will run a few inches from the anchor to be soldered to the switch.

Another problem is the receiver employed has a sum total one pure analog input (labeled "DVD 7.1") and there are two analog sources, CDP and Strain Gauge phono.  So will put another switch in the above box, DPDT gold contact, with two hard wired stereo inputs and one stereo output to the Trinaural processor input (same AWG12 to be anchored as described). 

From the rear this box will be an ugly sight.

Then remove the hard wired AC cable from my backup receiver, cut the frame to accept an IEC socket with a Dremel (must physically isolate the space), attach the socket and the wires.  Seemed to be an audible upgrade on the first receiver.         
Title: Re: What equipment are you currently working on?
Post by: jkeny on 18 Apr 2010, 01:27 am
I spent the last couple of evenings tweaking the power supplies in my DAC. The DAC is one of the 1st gen Twisted Pear Buffalo board but I swapped out the ES9008 for the ES9018 chip. I'm using transformers for the output and feeding it via IS2 via a disassembled hiFace USB interface mounted right next to the DAC board.

Previously I was feeding the Buffalo board via a couple of LT1085 based regulators. The hiFace module had a fairly elaborate 5V supply I built that incorporated some of John Broskie's ideas on a feed-forward regulator. The overall result was quite good but I knew there was considerable room for improvement. In December I picked up some of Paul Hynes shunt regulators and they have been sitting until I finally had some time to tinker with it.

The end result is I added 6 new regulators to the DAC; a 3.3V for the clock, a 1.2v for the core voltage, 2 x 3.3v for the analog voltages, a 5V in front of the two digital regs and finally a 3.3v for the clocks in the hiFace in place of the DC-DC converter as suggested by John Keny though not a LiPo battery like he is using. The 3.3v for the hiFace is being fed by the feed-forward supply and the 2 x 3.3's for the AVCC are being fed from one of the 1085 based regs. The 5v shunt that feeds the digital is being fed by the raw 9V supply.

I have to say that so far the result are well worth the effort and expense. I spent a while listening last night and I kept wondering where the sock that was over my speakers went. I was hearing low level details in a very familiar recording that I have not heard before. The system seems faster and has better timing. I could not stop my feet from bouncing. Given that everything is brand new and none of the electrolytic caps have had a chance to form, it will be interesting to see if things change any.

Some may ask, why no photo. It's ugly, just really ugly. At least on the inside. I built it into a old Musical Fidelity A324 DAC chassis, so it looks pretty good on the outisde, but it's very busy on the inside, a result of build, change, change, change and change... so things are not as clean as if I'd started from scratch. :)

Well done Mike, you took the plunge - well worth it  :eyebrows:

The improvement in PS to the Buffalo will have made a substantial change in the sound.
The PS improvements in the hiFace will greatly improve the sound - try to get as clean a PS as possible for the clock to further improve the sound.

Mine has since been improved by boxing it all up together with batteries, on/off switch, led & charger socket. See here: http://sites.google.com/site/hifacemods/

Another user has a preliminary report on the sound here:
http://www.head-fi.org/forums/6557756-post1185.html
Quote
Abstract:
I was totally floored by what I heard. The improvement was real and big compared to the other converters. What impressed more about the modded hiface vs. the other converters is that the modded hiface made everything sound real while the others struggled at various degrees to portray a poor copy of the real thing.
I just didn't have the strength/will yesterday night to switch to another dac to confirm my findings. I was able to just sit back and listen to the music without analyzing it ... which is a rare thing for me

(http://6437896050168339513-a-1802744773732722657-s-sites.googlegroups.com/site/hifacemods/home/boxed%20back%202.JPG?attachauth=ANoY7cp2EPLj3QUYhCKlNwH33CTjMGpsAN_0XSC4mEx2zKdrfHLNm-SM9B1DsevWjqzO4rAjnwDedQoLYUp0Z7dqW2-41l6_Q2OszOxxaXHh3yHxEeF_igsqyYeHb5Q8vkaOSLP9JsuB8zwpBw3z_kABiU55iCJh3YHQCm6_3p8xUGuku1jXCM6R9wNnyO9UcGyPFXOc-FRaaktWlsbIoSTrLNFWYAcdzQ%3D%3D&attredirects=0)

Title: Re: What equipment are you currently working on?
Post by: 56oval on 18 Apr 2010, 11:00 am
Hi
 Its been awhile so heres an update .I just finished making a jig to clamp and glue my speaker cabs .
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_4979.jpg)
Painted and ready to clamp
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5000.jpg)

Cheers
Title: Re: What equipment are you currently working on?
Post by: jkeny on 18 Apr 2010, 02:09 pm
A full review of the modified hiface just published: http://www.head-fi.org/forums/f7/review-jkeny-s-modified-hiface-483900/
Quote
Preliminary conclusion:

Contrary to what I am used to, I have made very few musical examples simply because it is very dependent on the associated DAC.
The modified Hiface is a very transparent device. It doesn’t have a sonic signature of its own. As far as I could tell, the overall sonic signature will depend more on the associated equipment and the recording itself than on the modified Hiface itself.
For more details about musical examples, I invite you to read my review of the DAC19DSP for which I used the modified Hiface as a transport. (See here: http://www.head-fi.org/forums/f7/review-audio-gd-dac19dsp-c2-amp-acss-connection-483899/).

While the modified version that jkeny sent me is still a prototype, I can say that it by far the best converter I have listened to in my system. I was expecting a small improvement (since I considered the stock one being excellent) but I was totally surprised by the level of performance of the modified Hiface. Its effect on the sound was not subtle at all.

jkeny described the sound of the modified Hiface as similar to that of expensive analog and I couldn’t agree more: his modified Hiface make the other converters sound broken.

Personally, I have already asked jkeny if I could send him my stock Hiface to have a similar mod done to it.
Title: Re: What equipment are you currently working on?
Post by: James Romeyn on 18 Apr 2010, 08:37 pm
Nope,
...Lead filled Birds Eye Maple...
-West

WHOA!  I'd love to see/hear/taste/smell/touch that!  Well, maybe not taste... 
Title: Re: What equipment are you currently working on?
Post by: face on 3 May 2010, 08:15 pm
Just upgraded from Auricaps to Sonic Cap Platinums in my Mapletree Line 2A.  I maybe have 20 hours on them and so far I'm very pleased with what I hear.  Next up are Vampire copper RCA jacks. 
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 15 Jun 2010, 02:49 am
Assembling a Transcendent Sound (http://www.transcendentsound.com/tube_analyzer.htm) tube analyzer. It takes considerable time to assemble this, lots of point to point wiring but I'm getting close. I decided to paint it red, the chassis was bare aluminum and was just butt ugly IMO. Not that my paint job is all that good but it's worlds better than bare metal. ;)


(http://www.audiocircle.com/image.php?id=31581)


Title: Re: What equipment are you currently working on?
Post by: mgalusha on 19 Jun 2010, 03:22 am
Finished the tube analyzer last night, worked first try, which is always nice after a lot of work.

So far I can say this is a very cool piece, at least if you're interested in knowing what your tubes are really doing and wish to design/modify around them.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: jrebman on 19 Jun 2010, 04:53 pm
Mike,

Nice piece of gear!

I'm currently working on 4 projects, but mostly in the wood/metal working stage:

A bottlehead Crack headamp, a new base and some small modifications to my BH s.e.x. amp, finally getting around to finishing my zigmahornets, and building a dual linear regulated PSU to power my music streaming computer (either the Asus EEE box or the Alix board) and one for the LDR attenuator.  That will eliminate the last two switchers from the system and save one AC outlet as well.  Plan to have internal felix board or boards, split-bobbin trannies, etc.

Pictures whe there's something interesting to post -- right now everything is separate little assemblies that have or have not been painted and finished.

-- Jim
Title: Re: What equipment are you currently working on?
Post by: 56oval on 21 Jan 2011, 03:38 am
Hi
I was going to highly polish the copper top plate of my amp but I decided to go with a engined turned/jewelled look .Its given the copper a holygraphic look and the bonus the wife really likes the look of it .
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5658.jpg)
I finished it off with 3 coats of Incralac sprayed on with a 1.7mm nozzle,which is a clear vanish for copper & copper alloy's .

Cheers

Mal
Title: Re: What equipment are you currently working on?
Post by: sl_1800 on 21 Jan 2011, 02:04 pm
56oval that is sweet.  :)
Title: Re: What equipment are you currently working on?
Post by: JoshK on 21 Jan 2011, 02:14 pm
Wow, that looks sweet!  How much did that copper stock cost? Is it an alloy?  Also, where did you have it machined to look like that?  Was it expensive?
Title: Re: What equipment are you currently working on?
Post by: 56oval on 21 Jan 2011, 11:32 pm
56oval that is sweet.  :)
Thanks sl_1800 ,it looks a bit more interesting than just plain polished copper .

Wow, that looks sweet!  How much did that copper stock cost? Is it an alloy?  Also, where did you have it machined to look like that?  Was it expensive?
Hi Josh

The 5mm copper plate wasn't cheap ,I think it was around $400.00 for a sheet @ 900mm x 800mm the grade of the copper is C11000 temper=1/2 hard , bought enough to do 4 amps .

I done all the machining myself at home using a drill press ,grinder and a sander .To get the round swirls I used Cratex rubberized abrasive stick's in coarse grade and a grid pattern .Then sprayed it with Incralac to protect the coper finish.
Heres a shot after I sprayed the top plate and rectifier plates for each amp .
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5656.jpg)
The plates to mount the chokes and power transformers and the brass stand off's I'm making .
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5675.jpg)
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5672.jpg)


This is the midrange amp ,I'm building a smaller version for the Raven R1 tweeter .

Cheers
Title: Ampslab LM60 amp and Pass B1.
Post by: nodiak on 21 Feb 2011, 01:40 am
Been very curious about the LM60 as it uses Hitachi Lateral Mosfets, claimed to have some nice tone and harmonic richness. Putting it in a Hafler 220 chassis. Resistors and caps soldered in, transistors to go. 300va, 30-0-30v transformer. Rated at 60 watts/8 ohm, 80/4 ohm. Current speakers are 90db/4 ohm. Working to finish it this week. Pic of fitting parts into chassis.
Finished the B1 to a working state, chassis needs faceplate and damping. Sounds good so far - open, big soundstage, deep bass. Currently using Classdaudio cda254.

(http://www.audiocircle.com/image.php?id=43089)
Title: Re: What equipment are you currently working on?
Post by: 56oval on 21 Feb 2011, 01:05 pm
Almost done just need to get 2 chokes gapped once there in position
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5985.jpg)
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5981.jpg)
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5986.jpg)
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5988.jpg)
(http://i55.photobucket.com/albums/g158/malcolm_05/IMG_5762.jpg)

Cheers
Title: Re: What equipment are you currently working on?
Post by: poseidonsvoice on 21 Feb 2011, 02:11 pm
No need to go to a show. The 2C22 is a great tube. A predecessor to the 6SN7, essentially 1/2 of it.

Stupendous parts quality!

The state of the art is right here.

:notworthy:

Anand.

P.S. Care to share the schematic?
Title: Re: What equipment are you currently working on?
Post by: 56oval on 24 Feb 2011, 02:59 am
No need to go to a show. The 2C22 is a great tube. A predecessor to the 6SN7, essentially 1/2 of it.

Stupendous parts quality!

The state of the art is right here.

:notworthy:

Anand.

P.S. Care to share the schematic?
Thankyou for the kind words mate  :D. My mate who drew the schematic up and made all the iron doesn't want me to put the circuit upfor public view until the amps are up and running and fully tested to make sure it works and is safe .The other issue is a number of the chokes are wound with custom values so you would need to get him to make them plus its his day job .

Cheers
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 24 Feb 2011, 03:38 am
Amazing looking, just beautiful.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: JoshK on 24 Feb 2011, 02:53 pm
Obviously a labor of love!  Looks awesome!
Title: Lightspeed / Warpspeed attenuator
Post by: GBB on 6 Mar 2011, 10:09 pm
Since I always have more plans than time, I decided to do something quick and dirty.  I've been reading about the Lightspeed attenuator and its many variations over at diyaudio.  This is a passive preamp using optocouplers as variable resistors.  The benefit claimed from these is that it gets rid of the contact in standard potentiometers, leading to much greater transparency than any other volume control.  I bought a quad of matched optocouplers and a small VCCS module (voltage controlled current source) from a gentleman by the name of "Blues" over on diyaudio.  I put it in a small plastic box that I bought at Fry's and I'm running it off of a pair of 9v batteries.  It's configured as 2 inputs (toggle switchable) and 1 output.  I've also run it off of a small HP lab supply with equivalent results.
The sound is really good.  As promised, it's got great transparency and shows lots of detail even at very low volumes.  I think it might be missing just a bit of drive compared to a really good active preamp but that transparency is really something.

Here are a few pictures of the preamp.
---Gary

(http://www.audiocircle.com/image.php?id=43759)

(http://www.audiocircle.com/image.php?id=43760)

(http://www.audiocircle.com/image.php?id=43761)
Title: Re: What equipment are you currently working on?
Post by: 56oval on 5 Oct 2011, 12:35 pm
Still plugging away ,but getting closer
(http://i55.photobucket.com/albums/g158/malcolm_05/Raven%20R1%20amp/IMG_6391.jpg)
(http://i55.photobucket.com/albums/g158/malcolm_05/Raven%20R1%20amp/IMG_6369.jpg)

CHeers
Title: Re: What equipment are you currently working on?
Post by: poseidonsvoice on 5 Oct 2011, 12:41 pm
Still plugging away ,but getting closer
...
CHeers

I think I just fell off my chair. Kudos  :thumb:

Anand.
Title: Re: What equipment are you currently working on?
Post by: jtwrace on 5 Oct 2011, 12:46 pm
I think I just fell off my chair.
Anand.

You know what I want to do....the CNC is ready if / when you are.   :green:
Title: Re: What equipment are you currently working on?
Post by: 56oval on 5 Oct 2011, 12:55 pm
I think I just fell off my chair. Kudos  :thumb:

Anand.
You know what I want to do....the CNC is ready if / when you are.   :green:

CHeers guys .

No CNCing all cut & drilled by hand ,even the engine tuning  :) .

Cheers

Mal
Title: Re: What equipment are you currently working on?
Post by: mgalusha on 5 Oct 2011, 06:27 pm
Still plugging away ,but getting closer
(http://i55.photobucket.com/albums/g158/malcolm_05/Raven%20R1%20amp/IMG_6391.jpg)

Lovely, absolutely lovely. I've been thinking about a 2 deck amp but there is a near zero chance it would turn out like these.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: 56oval on 24 Nov 2011, 05:02 am
Thanks mg

Slowly getting closer with the speaker build .
(http://i55.photobucket.com/albums/g158/malcolm_05/4%20way%20speaker/IMG_6427.jpg)

Once these are done then 15" bass cab's need to be built .

CHeers
Title: Re: What equipment are you currently working on?
Post by: Haoleb on 17 Dec 2011, 03:40 pm
This is my latest creation... I call it my Tube lAMP.

Havent been able to DIY much in the last year and a half since I moved and no longer had access to some of my tools and living in a small apartment with no area to work on things or keep stuff like saws if I bought them. But I got restless and a while back saw these cool light bulbs designed to be like the old style filament bulbs that arent very bright and remind me alot of tubes. Finally last weekend I decided to undertake a project!!!

This is what I ended up with. What does it do? Nothing really.. But it looks freakin cool. Pictures dont really do it justice, especially the bulbs which are very neat. Not super bright so you can stare right at them and a warm orange glow almost like staring into flame. All the bulbs are 30watt. The voltmeter is an NOS simpson I got off ebay. Really nice meter too, All metal construction, glass face. Too bad they dont make em as good anymore.

The case is solid maple, I added in a peice on the front to build up the profile so I could fit the meter in there. And cut the sides so the top and bottom would fit flush into the box so you dont see any end grain except the top triangle peice. I also added in some brass pins to the top to look like fasteners although everything but the bottom peice is all glued together. The bottom screws in with some stainless 1/4-20 allen head bolts I tapped the wood to thread them right in, which is working very well the wood is hard enough to take threads quite easily.

The wiring inside looks like hell but my choice to use some 14awg 1000v 105c mtw wire was a bit overkill and trying to get it all to look good in such a small space didnt pan out so well... Anyway, Onto the Pics!


(http://haoleb.com/audio/lamp3.jpg)

(http://haoleb.com/audio/lamp4.jpg)

(http://haoleb.com/audio/lamp2.jpg)

(http://haoleb.com/audio/lamp5.jpg)

(http://haoleb.com/audio/lamp1.jpg)

(http://haoleb.com/audio/lamp6.jpg)

(http://haoleb.com/audio/lamp7.jpg)
Title: Re: What equipment are you currently working on?
Post by: jeffreybehr on 17 Dec 2011, 05:25 pm
I'm continuing to improve passive parts in my quad of Marantz MA-24s.  I biamp Vandersteen 5As with them, so 2 are dedicated to lo frequencies (and receive fewer new parts) and 2 are hi-trequency amps and get more parts.  I'm close to finishing.   :)  Here's an early shot with the predecessor smaller/larger MA-22s just out and still loose.
(http://i89.photobucket.com/albums/k220/jeffreybehr/Marantz%20MA-24/11Oct2011_24sfirsthereinplace_1280w.jpg)

HF on the left; LF on the right.  Notice the SoniCap Platinum Teflon-alloy-film output-stage-bypass caps, 1.47uF per pole.  One of the 3 small 'lytic caps on the board has been replaced here.
(http://i89.photobucket.com/albums/k220/jeffreybehr/Marantz%20MA-24/07Nov2011_Ampstopless_1280w.jpg)

An early shot of a LF amp.
(http://i89.photobucket.com/albums/k220/jeffreybehr/Marantz%20MA-24/12Oct2011_bottom_2ndbypass_1280w.jpg)

An early HF-amp output-stage-PS bypass.  Rail is 31VDC; caps are the now-rare Black Gate-VK 2200/35s.  I now use 2 on each pole.  Have done more since including replacing most PS and neutral wiring with Neotec 14g. UPOCC-stranded-copper wiring and Audioquest silver-over-OFC-copper spades.
(http://i89.photobucket.com/albums/k220/jeffreybehr/Marantz%20MA-24/12Oct2011_OSbypasscaps_1280w.jpg)

This stuff is great fun and serves the public further in keeping me off the streets and out of the bars, as they say.  :roll:

More info here.  http://jeffreybehr.myblogsite.com/
Title: Re: What equipment are you currently working on?
Post by: Speedskater on 17 Dec 2011, 10:21 pm
Jeffrey, what are the copper wire things on the amps covers on the carpet?
Title: Re: What equipment are you currently working on?
Post by: jtwrace on 17 Dec 2011, 10:39 pm
Jeffrey, what are the copper wire things on the amps covers on the carpet?
I'd say vibration control.
Title: Re: What equipment are you currently working on?
Post by: ammisco11 on 22 Apr 2012, 08:06 pm
Currently I'm working on new cabinets for my Ellis 1801.b and Denis Murphy designed Hiquphon OW2, Seas Excell, Peerless10" 3 way.  My stone fabricator just bought a $250,000 granite CNC and we decided to try it out making granite baffles for MDF veneered cabinets.  The results on the test pair were to say the least... encouraging  :drool:.  We are also making a sub from a hollowed out solid block of granite.

Solid Granite MTM speaker cabs.
(http://www.audiocircle.com/image.php?id=61592)

Hollowed block of solid granite down firing 8" sub
(http://www.audiocircle.com/image.php?id=61590)

CNC cutout for plate amp.
(http://www.audiocircle.com/image.php?id=61591)
Title: Re: What equipment are you currently working on?
Post by: pjchappy on 22 Apr 2012, 08:52 pm
Still plugging away ,but getting closer
(http://i55.photobucket.com/albums/g158/malcolm_05/Raven%20R1%20amp/IMG_6391.jpg)

 :o  Wow!  Very, very nice! :thumb:


Paul
Title: Re: What equipment are you currently working on?
Post by: Freo-1 on 22 Apr 2012, 09:49 pm
Just starting on a pair of monoblocks.  Will be ordering transformers in the next week or so.

Will go with a a pair 12SN7 input tubes, and a pair of 1625 output tubes.

Expect to get roughly 40 to 50 watts from each monoblock. 
Title: Re: What equipment are you currently working on?
Post by: Scott F. on 29 Apr 2012, 06:02 pm
Earlier this week I went to visit Deadfish (Bill) who was parting with a fair amount of his gear that has been building up over all these years.

I picked up an old Fisher Futura II from 1962. As I mentioned to Bill, I really only wanted it because of the nine Fisher/Telefunken 12ax7 tubes. I told him that was going to pull the amp but all I would do was harvest the iron then trash the chassis. The amp is a 7591 based PP. It's a typical ultra-linear with NFB and selenium rectifiers.

As I got the amp back home I decided to look at the schematic. I've gutted a number of the older consoles over the years an many times the wiring pigtails between the separate chassis are loaded with switching, small signal wires, B+, filament power and grounding which makes it a PITA to create a stand alone amp. I normally just harvest select parts and iron and call it a day.

This one I got lucky. I only had to reroute a minor amount of B+ plus some grounding in order to get her to fire up. As I tested it on the bench, it sounded pretty darned OK on my little test speaker so I decided to make a little wood cheeked case for it. Nothing too elaborate, just something to dress it up a bit.

Here's a pick of the finished case. All I did was take a bit of old oak handrail that I had leftover, sawed it in half and then mitered the corners. I used a red based stain then shot it with about 8-10 coats of semi-gloss urethane. If you look close you'll see I was able to work in the Fisher Anniversary Series badge as a the name plate.

(http://www.audiocircle.com/image.php?id=62004)


On the back side I installed an IEC plug


(http://www.audiocircle.com/image.php?id=62006)


I left her completely unrestored. I didn't change any caps (I brought her up really slow on the variac to reform all the caps). I left the old rectifiers and resistors in place. That may (will) become an issue at some point but, I'll deal with it when they fail. Oh, obviously I had to install a power switch. I popped out one of the two power outlets and stuck a cheapie snap switch in its place. Also, I decided to pull the wiring out for the auxillary speaker terminals. I also replaced the speaker lead wires from the transformer to the terminal strip.


(http://www.audiocircle.com/image.php?id=62003)

(http://www.audiocircle.com/image.php?id=62005)


It's kinda cool if I don't say so myself :green: I'll end up using this in my shop in the basement to feed a pair of Infinity Qe's. For the time being, I'm going to leave her untouched, rust, oxidation and all. If she turns out to be really reliable, I may pull her apart and give her a good polishing and some fresh paint on the transformers.  :thumb:
Title: Re: What equipment are you currently working on?
Post by: JoshK on 29 Apr 2012, 07:01 pm
Nice score and nice job with the quick restore.  A lot to be said about getting her up and running versus forever a project.

I am finishing up a quad of Anarchy tapped horns and working to finish my Geddes Abbeys.
Title: Re: What equipment are you currently working on?
Post by: Scott F. on 29 Apr 2012, 10:55 pm
Thanks Josh.

Yep, I've got tons of those 'wunna these days' projects  :duh: It's been so long since I've done anything audio related (as far as building) that I said screw it, I'm building something (sort of) that I can finish in a weekend. This just happened to be it.

It's surprisingly decent. I've got it in service right now on the shelf above my head in the shop. I'm feeding it directly from the sound card in desktop built before the turn of the century. There was an impedance mis-match causing noise and other nasties so installed an old Creek OBH-10 passive pre. Worked just fine to kill the noise and most of the nasties. Lost some transparency but that's just fine. One thing, this old Fisher delivers bass by the truckload  :thumb: I've got Victor Wooten pounding the crap out of the shop right now. Kinda fun!

Those Anarchy's look like a pretty cool project. Be sure to post your impressions of the bass quality after you finish them :thumb:
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 29 Apr 2012, 11:11 pm
Josh, I  am also interested in your opinion on the Anarchy tapped horns. I only built two but the output was just way too low. I would say the bass quality was good but they where also push too hard too easily. I could not fit four but that could make a big difference.
Title: Re: What equipment are you currently working on?
Post by: WireNut on 6 Sep 2012, 11:01 pm
One of two push-pull subs I'm working on.
(http://www.audiocircle.com/image.php?id=67358)

(http://www.audiocircle.com/image.php?id=67359)
Title: Re: What equipment are you currently working on?
Post by: SET Man on 6 Sep 2012, 11:20 pm
Hey!

    Just saw this, Scott F nice job with the amp. The wood frame make it looks much better and the Fisher badge is a nice touch.  :D

Take care,
Buddy  :thumb:
Title: Re: What equipment are you currently working on?
Post by: Folsom on 15 Dec 2012, 03:42 am
I just cut off all the plastic on the electrolytics in my preamp (high end bugle and PS) and my amplifier (a fancy GC 3875).

Maybe some day I'll consider the wood upgrade but to be honest... this was more than worth the few minutes with a pocket knife. If your system is lower powered... Do yourself a favor, it only takes a few minutes. It wasn't a minor upgrade in sound; piano is very 3D and rings. Why does it work so well? Shit if I know... they are all in the power sections anyways? Nevermind, how about the words holy shit! I had done it before any never noticed much, but only on a few. Do your whole system and be ready for holy shit...

I have considered the idea of dampening them with wood, instead of replacing the metal. (what a pain, most circuits don't have room).
Title: Re: What equipment are you currently working on?
Post by: Frihed91 on 27 Jun 2013, 07:09 am
56oval that is sweet.  :)

Earlier I saw you had a bunch of double C core OPTs.  Now I see them (or some more) again.  They look like Audio Note, but you mentioned earlier that they were hand wound by someone else.

Is that person in the business of selling custom OPTs and Interstage transformers?

So many small mfrs of really good Txs seem to be operating under my radar.
Title: Re: What equipment are you currently working on?
Post by: sts9fan on 10 Mar 2014, 03:03 pm
Finally started work on my F5 Turbo V2.
Here is the start of the PS.
(http://i.imgur.com/OTqPWwC.jpg)
Title: Re: What equipment are you currently working on?
Post by: wakibaki on 28 Apr 2014, 05:02 pm
(http://wakibaki.com/images/electrostatic_II.jpg)

My electrostatic phones. A work in progress.

w
Title: Re: What equipment are you currently working on?
Post by: ACHiPo on 13 May 2016, 09:54 pm
It may be premature, but I just pulled the trigger on a donor Lenco L75 that will be transformed into (hopefully) an amazing second turntable.