What equipment have you built recently?

Warpspeed CE · « **Reply #140 on:** 21 Sep 2011, 03:25 am »

This unit is a keeper! It is still under evaluation/listening tests but very,
very promising indeed...

For passive bi-amping with separate high and mid/low level controls, and a master volume control. This takes advantage of the loudspeaker designer's optimized crossover/driver combination...a chance to appreciate his art.

poseidonsvoice · « **Reply #141 on:** 30 Jun 2012, 03:48 am »

In order to complement my rigged Mac Mini 2009 I built a custom linear power supply that puts out ~ 18V DC.

Ingredients are as follows:

Furutech FI-10 IEC
ACME fuse
Neutrik 4 pin NC4FD-L-1
Antek AS-2220 transformer w/magnetic shielding, electrostatic shielding and a CA-200 steel cover
Paul Hynes PR3iEHD-18v5 w/ additional off board Nichicon Gold Tune Super Through 4700 uf capacitors
Bybee 15A Music Rail w/20uf polyproplene in oil input capacitor
VT4C AL-299B chassis
DC connector cable made using matching 4 pin Neutrik male plug and connector assembly instructions
Schematic for DC connector cable assembly
Aluminum from Online Metals for heatsinking
Front Panel Express for engraving/drilling of all panels

A couple of points. For the DC connector cable, I designated Pin 4 as my Hot/+18V/Red wire; Pin 2 as my Sensor/Grey wire; and Pin 1 as my Ground/Black wire. In addition, you will see how I connected the 0.1uf/100V capacitor to the shield of the Neutrik jack and to Ground/Pin 1. This 4 pin Neutrik was used as a matter of convenience. There is more space when you have 4 pins around, even though one pin is left unused (Pin 3 in this case).

I tried this power supply with and without the Bybee MR installed. Using the Paul Hynes series regulator & supply it offers excellent performance as you would expect as an upgrade from the stock Apple switcher supply which wasn't designed for audio (compared to some other finely designed switchers in the audio industry - all of them at this point come from a small company in the Netherlands!). However, the Bybee MR to my ears, does improve the performance but slightly. You wouldn't miss it in most systems. Since I decided to use the Bybee MR, I had to account for the 2V DC voltage drop, and as such used a toroidal transformer with 20V secondaries instead of 18V secondaries. The Paul Hynes unit has an onboard potentiometer for fine tuning of the output voltage. The Nichicon Gold Tune Super Through capacitors were recommended to me by Peter Daniel who found it was a close second in sonics to Jensen's famed 4 pole electrolytics. I could not implement the 4 poles in this design as I would've had to hack into Paul Hynes' excellent board which I didn't want to do. Make sure you design for adequate heatsinking and heat sink compound. I used a 3/4 inch thick (20mm) piece of aluminum that was 6 inches by 5 inches (152 mm by 127 mm) in addition to the chassis itself. It runs warm but not uncomfortably warm.

The unit measures at 17.99V without a load and about 17.96V with the Mac Mini & 1 external firewired hard drive. With the load on, I measure absolutely no AC perturbations on the output. In addition, the unit is silent as a mouse, no buzz at all with my ear on the chassis.

Let me know if you have other questions.

Best of luck in your builds

,

Anand.

Special thanks to jtwrace, Wayne of Bolder Cables, and Paul Hynes.

planet10 · « **Reply #142 on:** 30 Jun 2012, 05:35 am »

Rhanx for bringing this thread back poseidon

µFonkenSET in solid Western Red Cedar (SET = special edition trapezoid), and these little puppies are certainly special.

dave

Paul Hynes · « **Reply #143 on:** 30 Jun 2012, 09:38 am »

Nice build as usual, Annan.

Interesting that you found a small improvement using the Bybee. The PR3 is pretty quiet but perhaps additional noise reduction is still worthwhile. Of course there may be other reasons that you heard an improvement but one can only speculate, as it is a sealed unit. A good result overall.

Regards
Paul

TomS · « **Reply #144 on:** 30 Jun 2012, 12:06 pm »

Lovely work Anand, with the usual meticulous attention to every detail

richidoo · « **Reply #145 on:** 30 Jun 2012, 01:10 pm »

Handsome power supply Anand!

Love the speakers Dave!! My wife says "they're beautiful..."

mjock3 · « **Reply #146 on:** 30 Jun 2012, 01:54 pm »

Very nice Anand!

Thanks for sharing the particulars of the piece also. Much appreciated.

Occam · « **Reply #147 on:** 30 Jun 2012, 04:16 pm »

Anand,

Very nice build!
Kudos on your choice of a toroidal transformer with with a shield between primary and secondary. It makes for an effective shunt to ground for line noise which without shield would capacitively couple from primary to secondary.

Regards,
Paul

poseidonsvoice · « **Reply #148 on:** 30 Jun 2012, 04:41 pm »

Quote from: Occam on 30 Jun 2012, 04:16 pm

Anand,

Very nice build!
Kudos on your choice of a toroidal transformer with with a shield between primary and secondary. It makes for an effective shunt to ground for line noise which without shield would capacitively couple from primary to secondary.

Regards,
Paul

I really wanted to do EI core, but at these sizes (200+ VA), they hum and buzz. So the next best choice was a toroid with electrostatic shielding, magnetic shielding and a steel cover. Well worth the money.

Anand.

planet10 · « **Reply #149 on:** 30 Jun 2012, 08:54 pm »

Quote from: richidoo on 30 Jun 2012, 01:10 pm

Love the speakers Dave!! My wife says "they're beautiful..."

And the picture doesn't really give much idea of the size (that is a 3" driver)

dave

jtwrace · « **Reply #150 on:** 30 Jun 2012, 09:08 pm »

Quote from: poseidonsvoice on 30 Jun 2012, 04:41 pm

I really wanted to do EI core, but at these sizes (200+ VA), they hum and buzz.
Anand.

Like mine.

sts9fan · « **Reply #151 on:** 1 Jul 2012, 12:30 am »

Here is my halfassed F5. The thing is Silent!

GBB · « **Reply #152 on:** 2 Jul 2012, 01:41 am »

I just finished building a DAC based on the Twisted Pear Audio Buffalo III kit. It has the Buffalo III DAC board with the latest Trident regulators from TP Audio. I use a single SPDIF input module. Outputs are transformer coupled using Sowter 1:18.7 transformers. The output of the Buffalo DAC is loaded with 25ohm resistors. That combined with the step up of the Sowters gives a "normal" level for the DAC. I buffer the transformers with a discrete FET buffer so that there is sufficient drive. I've found that transformer output alone can sound a bit light weight.
The whole thing is powered by an R-core transformer I got off of ebay - 120v/240v primary with dual 9v and 15v secondaries. The 9v secondaries are paralleled to drive the digital section and the 15v primaries are rectified and regulated to give +-15v for the FET buffer. The digital section is regulated using a Placid HD shunt regulator from TP audio while the buffer uses LT1086 adjustable regulators. I've only had it working for an hour or so but it sounds pretty good so far. Definitely worth the effort.
I built the DAC in a wooden box. The bottom is 1/2" baltic birch plywood, while the sides and top are solid oak. Below are a few pictures of the finished DAC.
---Gary

mgalusha · « **Reply #153 on:** 2 Jul 2012, 01:47 am »

Very nice Gary, I built a Buffalo II based DAC in a similar fashion but used Lundahl's on the outputs and it sounds quite nice. I ended up with only a 1V output to keep the Zout down and as you mention, to keep it from sounding a bit thin. I had plenty of gain in my preamp, so this was an acceptable trade in my situation but I like the FET output buffer, lots of drive there.

mike

poseidonsvoice · « **Reply #154 on:** 2 Jul 2012, 01:49 am »

Nice work Gary! I am just waiting for TP to make their 24bit/192khz compatible USB board and not have to resort to the exaDevices unit.

Best,

Anand.

Bob in St. Louis · « **Reply #155 on:** 8 Jul 2012, 09:44 pm »

I guess you could call this "equipment"...... It helps me listen to music, so I suppose so.

When I sit at my computer desk I like to listen to music. The tunes are on a server located in the rack with the rest of my equipment, but I control the tunes remotely via a Samsung Galaxy 10.1 that sits on the desk next to me. I've got a leather case that holds the tablet vertical but the problem with that, is when it's sitting vertical, the charge cord can't plug in because in Samsung's wisdom, they put the charging jack on the bottom. So I can either keep it plugged in and lay it flat, or stand it up and not charge it. Laying flat is hard to read and since it may be on all day, not charging it isn't an option.

I've looked for "off the shelf" solutions and can't find one, so I made one.
I built a stand that holds it up high enough that the cord can still be plugged in.

Oh happy day.

Some day I may put some kind of finish on it. For now, it's just fine.

mgalusha · « **Reply #156 on:** 8 Jul 2012, 09:48 pm »

I like the stand Bob, very nice. I'll bet you had some spare baltic birch left over from one of your many speaker projects.

Bob in St. Louis · « **Reply #157 on:** 8 Jul 2012, 09:51 pm »

Quote from: mgalusha on 8 Jul 2012, 09:48 pm

I like the stand Bob, very nice. I'll bet you had some spare baltic birch left over from one of your many speaker projects.

Yessir, I do. Thank you for the complement Mike.

mgalusha · « **Reply #158 on:** 8 Jul 2012, 09:54 pm »

They say imitation is the sincerest form of flattery. Well I have an Acer A500 tablet and I may well copy your slick little stand. Now there's a compliment.

Bob in St. Louis · « **Reply #159 on:** 8 Jul 2012, 10:05 pm »

Quote from: mgalusha on 8 Jul 2012, 09:54 pm

They say imitation is the sincerest form of flattery. Well I have an Acer A500 tablet and I may well copy your slick little stand. Now there's a compliment.

I never thought I'd see the day when you would copy me Mike.

If I had one thing to change, it would be the depth of the back. It's tilted back about 12 degrees and the base doesn't extend far enough rearwards. I was trying to avoid having a huge plywood "structure" sitting on the desk, and wanted to make it slim looking. So if I touch the top of the screen too hard, it's a bit tippy.
Although I think a couple rubber feet in the back would fix that.

Bob