What equipment are you currently working on?

Berndt · « **Reply #160 on:** 5 Jan 2010, 02:49 am »

looks regaish

jeffdavison · « **Reply #161 on:** 5 Jan 2010, 04:52 am »

available as a spare from any Rega dealer. around $60 in the US

JD

sts9fan · « **Reply #162 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.

sts9fan · « **Reply #163 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.

Wardsweb · « **Reply #164 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.

Scott F. · « **Reply #165 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.

....I know, I know...without pictures, it really didn't happen. I forgot to take any....but it really did happen! Honest!

jeffdavison · « **Reply #166 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.

JD

JoshK · « **Reply #167 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.

poseidonsvoice · « **Reply #168 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!

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 ->

Anand.

jeffdavison · « **Reply #169 on:** 5 Feb 2010, 04:10 am »

took me a few years to get to this point

Change output to parafeed..

mgalusha · « **Reply #170 on:** 5 Feb 2010, 08:44 pm »

Very very cool. Love to hear that one.

jeffdavison · « **Reply #171 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..

jtwrace · « **Reply #172 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.

mgalusha · « **Reply #173 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.

jrebman · « **Reply #174 on:** 21 Mar 2010, 03:14 pm »

Mike,

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

-- Jim

JoshK · « **Reply #175 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.

AUDFILE74 · « **Reply #176 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.

James Romeyn · « **Reply #177 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.

jkeny · « **Reply #178 on:** 18 Apr 2010, 01:27 am »

Quote from: 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.

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

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

56oval · « **Reply #179 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 .

Painted and ready to clamp

Cheers