[JoshK]

Well I have sat on my ass too long about this and decide to put something down even if it isn't totally edited and organized fully yet.  We have mac to thank for the following information as he is the one responsible for the info below.  This was a collection of a few PMs mac sent to me about the various parts needed to build amps out of the UcD modules.

I will try to edit this for clarity and continuity little by little and hopefully those of us who are building these amps (quite a number of us here on AC) can add comments and details as well as answer questions for builders.  

As you may know there are a number of threads over on DIYaudio.com that describe this but the point of this thread is to be more clear and organized for those of us who aren't rocket scientists and/or don't do this for a living.



The power supply is very straightforward to build. This is a good article and worth a read: http://www.tnt-audio.com/clinica/ssps1_e.html.

You need to decide if you want to use independent power supplies per module. Also, your choice of UcD180 vs UcD400 will dictate what voltages you'll require for secondaries on your transformers and filter caps. The VA rating of the transformer(s) will be driven by your decision of how many modules you're going to run off the transformer. My 3-channel amps use two 180 modules and one 400 module. I'm also running independent power supplies for each module.

This is Hypex' recommendation for trannie VA rating:

UcD180 - STEREO (2 modules) 160VA.
UcD400 - STEREO (2 modules) 500VA.

I can supply you with a complete set of DigiKey part numbers if you decide to build the amps, but for now these are the transformers and caps that I used:

UcD180:

31-0-31VAC 130VA transformer - "Type ZTR0016": http://www.geocities.com/dmfraser77/parts4sale.html

2x 63V 12,000uF Elna Cerafine caps from PartsConnexion.

UcD400:

40V-0-40VAC 310VA Avel transformer from Parts Express.

2x 80v 15,000uF Samhwa caps from Ebay.

The only other major parts are the bridge rectifiers, which I got from DigiKey. Some people like using the expensive fast-recovery type bridges but I decided to use standard bridges.

Hope this helps. Let me know if you want all the DigiKey part numbers.

http://cornucopia.sytes.net/~mike/class-d/P1010297.jpg
http://cornucopia.sytes.net/~mike/class-d/P1010294.jpg
http://cornucopia.sytes.net/~mike/class-d/P1010295.jpg

The amps sound incredible IMO.


You need 2 (or multiple of 2) caps per module. The 180's should use 63v caps and the 400 modules should use 80v caps (assuming you want the maximum power it's capable of).

Yes, the 63V 10,000 uF Elna Cerafine's.

Yes, it's a Series 20 case from ParMetals. The dimensions of the case are 16"W x 12"D x 3"H and it's one of their standard sizes. I used one of their optional 16" dividers to mount the caps on.

The case is just big enough to house the Avel transformers I mentioned. You can order it directly from Avel. Also, the filter caps I previously mentioned span the entire 16" distance across the divider.

Here is a parts list for all the parts I ordered from DigiKey:

6 - GBPC3510DI-ND RECT BRIDGE GPP 1000V 35A GBPC
100 - H703-ND SCREW MACHINE PHIL 4-40X1/4 SS
50 - 1892K-ND STANDOFF HEX 4-40THR .375"L ALUM
6 - WM2603-ND CONN HOUSING 4POS .100 HI PRESS
30 - WM2612-ND CONN TERM 22-30AWG HI PRESS TIN

I got these from Mouser:

8 - 539-VR8 CLAMP 2-2.06 Mallory Mounting Hardware
4 - 539-VR6 CLAMP 1.75-1.81 Mallory Mounting Hardware

In addition to those parts you'll need RCA and/or XLR chassis jacks, chassis mount binding posts, fuse holders & fuses, IEC power entry jack, power switch, some miscellaneous hardware to mount the rectifiers and caps, a spool of 16g wire and a couple feet of small gauge wire to connect the input jacks to the modules.


There are probably a couple other small things that I forgot to mention. The modules mount to the chassis with M3 machine screws. You'll need some 0.25" "automotive type" female quick-disconnect connectors...

I got the RCA jacks and binding posts directly from Kwok Chung Lee in HK. The part # is RCA-805FG and his website is: http://www.vt4c.com/

[mac]

I hope Occam doesn't rip me a new one over the content.  

[JoshK]

I noticed you (from the pictures) are using some Solen? caps to I am guessing bypass after the smoothing cap.  Care to share what values those were?

I asked Dejan if he could send us values for his schematics that were posted on tnt-audio (also on his website www.zerodistortion.com).

[angelo]

here are some nice chassis that can be used for this project



or



they're both from www.iagaudio.com and costs $140 and $105, custom drill cost $20 per chassis

angelo

[JoshK]

I just wanted to share a tiny piece of advice, if I may, being that I am a newbie to DIY myself.   Build on a project board (scrap plywood or similar) first, commit to a nice chassis second!  

I can speak from having learned the hard way, drilled out my chassis for a tube preamp, put all the pieces in the chassis, wire it up only to find out that my layout made it extremely difficult to get rid of hum.  It is much easier to test out layouts when you haven't committed to one with a nice expensive chassis.   (I noticed mac did this as well, so even experienced DIYers do this).  

I imagine it is also a lot easier to do parts swapping and evaluation when the amp is all on a board.

Second piece of advice, build with good but relatively inexpensive parts first, ones that will do the job sufficiently but aren't expensive boutique parts.   This is a common mistake we all make when starting on in DIY, to want to build the perfect component with all the highest priced parts.  It is very easy to screw up and ruin a very expensive part or realize it isn't the right part for the job.   I say get it working first and then try out parts swapping little by little and listen while you do it.

[mac]

I noticed you (from the pictures) are using some Solen? caps to I am guessing bypass after the smoothing cap.  Care to share what values those were?

The purpose is to lower the impedance of the power supply.  Large filter caps, even good ones like the Cerafines, have fairly high equivalent series resistance (ESR).  Placing good quality metallized polypropylene caps in parallel across the large filter caps will lower ESR and improve sound quality.  The value isn't too terribly important but the bigger the better (within reason).  Mine are 6.8uF Solen's.

Edit: Added the following gallery photo:

[Occam]

I hope Occam doesn't rip me a new one over the content.  

ME? For heaven's sake, why?  
 
I've been hoping you'd participate in a tangible project and share experiences from your impressive diy projects. I'll even provide Josh with some of the needed thingamabobs....

[Bingenito]

Time for a stupid question.

Can these be used for sub amps?

I have 2 pairs of Peerless XLS 12"s that I would like to drive in stereo with 1 or 2 amps. Min power 500 watts. I love the stainless chassis!

Is there anyway to get 500 or 600 watts @ 4ohms out of these modules (using more then 1?) If someone here were to build these for me what would the $damage be?

[mac]

Time for a stupid question.

Can these be used for sub amps?

I have 2 pairs of Peerless XLS 12"s that I would like to drive in stereo with 1 or 2 amps. Min power 500 watts. I love the stainless chassis!

Is there anyway to get 500 or 600 watts @ 4ohms out of these modules (using more then 1?) If someone here were to build these for me what would the $damage be?

Yes!  The UcD400 will deliver 400 watts into 4 ohms.  Your XLS drivers are closer to 3 ohms when connected in parallel.  That's no problem for this module as it's capable of driving less than 1 ohm loads.

I believe they can be bridged.  Check the diyaudio.com classd forum.

[Bingenito]

Any idea what the total parts cost is for 4- UCD 400's? I would like to bridge them and put them into 1 large (up to 7.5" high) or 2 small stainless chassis.

Balanced inputs and maybe Speakon ouputs

[JoshK]

So far I've calculated that I've spent $1100 on two UcD 400 modules and two UcD 180 modules each with their own toroid and PSU.  This is all the parts needed minus the case and the jacks which I have on hand.  However, I spent a pretty penny for those Elna Cerafine caps $34/ea (need 4 for stereo amps).  If you are building for bass amps then Sprague or Samwha caps should be fine and can be had much cheaper.  

I think you really don't need to bridge two amps Benny.  I, in my own novice estimation, think you'd be better off maximizing the stiffness and capacitance of the PSU.

[mac]

I think you really don't need to bridge two amps Benny.

I agree.  I'm running both of my SCC300's in parallel off of one UcD400.  My dipole woofers see about 12db of bass boost at 20Hz and I have yet hear the amps strain, even at insane volume levels.

[Davey]

Boy, I would hope they wouldn't be straining.  A UcD40 (if they made one) would have enough power for your woofer setup.  

Davey.

I think you really don't need to bridge two amps Benny.

I agree.  I'm running both of my SCC300's in parallel off of one UcD400.  My dipole woofers see about 12db of bass boost at 20Hz and I have yet hear the amps strain, even at insane volume levels.

[mac]

Boy, I would hope they wouldn't be straining.  A UcD40 (if they made one) would have enough power for your woofer setup.  

Davey.

Hey Davey, do you think 180 watts for the tweeter amp is adequate?  

[ss397]

this is a great thread, one of the best i've seen here. i wan't to thank you all for sharing. i intend to make a ucd amp of some type my next audio project as soon as i complete my current projects( subs, cables under constuction). i think the value with this technology is outstanding.

[angelo]

you can basically build this project for ~$550 (UcD400) or ~$450 (UcD150)

transformer = ~$60
rectifiers = ~$16
caps = ~$40 (ebay)
chassis, all connectors, wiring, fuse = ~$100

2 x UcD400 = $300
      or
2 x UcD150 = $200
---------------------------------

you can add ~$100 for each project for better PS caps and some extra filtering

-------------------------------------------------------------------------------------
this 100nF x2 rated capacitor can be used for additional filtering for each diode of the bridge rectifier:

Newark InOne Part No.: 96B2318

Manufacturer: BC COMPONENTS VISHAY

Manufacturer Part No.: 2222 338 24104

Description: Capacitors;Capacitance:100.0nF; Capacitance Tolerance:+/- 20 %; Voltage Rating:275 Vac; Dielectric Characteristic:Polypropylene; Lead Pitch:10
-----------------------------------------------------------------------------

angelo

[mac]

you can basically build this project for ~$550 (UcD400) or ~$450 (UcD150)

transformer = ~$60
rectifiers = ~$16
caps = ~$40 (ebay)
chassis, all connectors, wiring, fuse = ~$100

2 x UcD400 = $300
      or
2 x UcD150 = $200
---------------------------------

you can add ~100 for each project for better caps and some extra filtering

angelo

That's absolutely true.  A big savings can come from using a single power supply (one transformer and two caps) for multiple modules.

[amandarae]

Hey Mac,

I am thinking of building a UcD base 400 amp in stereo mode.  So far I have the following parts.

The transformer has the following specs.

http:// http://www.hometheaterhifi.com/volume_10_3/images/plitron-isolation-transformer.gif

The parts I have are:












I am sacrificing one of my Threshold amp to do a prototype since everything is basically there (input jacks, binding post, power switch, case, etc.).



So for the hypex UcD's rails (+- 63 volts rating), should this transformer be adequate?

What other tips or parts I need to get?  Thanks

[angelo]

the output of that transx is preety high... i'm not sure if it's ok to series some resistors to have some voltage drop and lower the DC output going to the amp modules

that's some serious transx you have there... does it require a dedicated 20A circuit per amp to run those 2 amps?

i'm sure some expert here can answer that,

angelo

[goskers]

That trannie after rectification will be too high for the UCD400 modules.

If I can get out of work at all these next coming days my 6 channel ucd amp should be complete.  I will post pics when all is said and done.