How to: Build your own Hypex UcD amps

CIAudio · « **Reply #40 on:** 3 Apr 2005, 10:15 pm »

Quote

This is Hypex' recommendation for trannie VA rating:

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

Keep in mind that these recommendations won't get you rated power. For example, we use a 300VA transformer to power a single UcD180 and get 175w at 4 ohms/.5% THD. Powering 2 UCD modules with a single 160VA would be significantly less.

angelo · « **Reply #41 on:** 23 Apr 2005, 04:44 am »

just an update on my project...

i tried to make it work tonight without the chassis!

i had some trouble making it turn ON... I didn't know that I have to ground the "/ON (internal pull-up)

it's been playing now for 30min (only 1 channel)

angelo

JoshK · « **Reply #42 on:** 23 Apr 2005, 05:17 pm »

Like the PSU board, did you design it yourself? What type of caps did you use?

angelo · « **Reply #43 on:** 23 Apr 2005, 06:57 pm »

josh,

the caps that i used are Nippon Chemi Con SMH Series 6800uF 80V, they cost around $7 each at newarkone.

i still have to add the filtering caps for the rectifiers. the powersupply design is basically from different PS guides that i read, TNT, ESP and from diyaudio members

the hard part was setting up the connection at the bottom of the PS board, i can't find a copper plate so i bought a copper tubing and flatten the surface, cut them and drill holes... it's a lot of work, if i have to do it again i'll buy a board pre-coated with copper and manually etch the unnecessary copper. A bleeder resistor is a MUST for both + and - rail especially when testing, you don't want to make connections when the caps are charged... even though the switch is OFF... or else

angelo

Gordy · « **Reply #44 on:** 23 Apr 2005, 07:00 pm »

Excellent Angelo,

How soon until you've both channels up and running? What are you using for input jacks/wiring? Could you point me to a source? My local computor repair shop gave me two sound card jacks that I'm using for now, but the captive wiring appears to be steel...

Thanks,
Gordy

angelo · « **Reply #45 on:** 23 Apr 2005, 07:17 pm »

i bough the input RCA connectors from partsexpress, i think they were $6/pair

for the input wiring I made them using "Belden-M 8771 CM 3C22 shielded (UL) E108998", that's what written on the cable. this is the perfect wire for the UCD, it has 4 conductors for +,-,GND,ON

i'm using direct connection to the speakers so I'm not using any binding post

i finished the second channel today so everything is playing. I just tried to see if everything is working and if my setup will work, i'll try to finish the complete amp (w/ chassis and all connectors) prolly by summer, too much work in school right now.

angelo

JoshK · « **Reply #46 on:** 23 Apr 2005, 07:26 pm »

excellent work. If I'd known you needed copper plating I would have given you some as I have quite a bit. Alternatively you can buy some Romex/g 12-2/g (NM-B) and cut it open and take the ground wire out and use some of it. it is solid 12awg copper which should work too.

Um, quick question. For all of us here, how did you wire the On/Off and the ground /On switching? There seems to be a lot of different ways of doing it, I haven't gotten that far myself so I haven't decided how I want to do it.

I just need to wire up my UcD 400s as I have pretty much done everything else. I just have umpteen million projects going in tandem it seems, but this is next up.

Gordy · « **Reply #47 on:** 24 Apr 2005, 05:56 am »

Once again I didn't ask the proper question, what I meant to ask about is the 4 pin female input jack on the module itself... can anyone point me to a source for new ones? It's the same jack as used on sound cards apparently...

I'll try posting pics of my preliminary, but running, layout tomorrow. It includes a 2 pole toggle mounted using extremely ugly scrap alum. bits for the signal ground on/standby switch...

Thanks

Gordy

JoshK · « **Reply #48 on:** 24 Apr 2005, 03:39 pm »

Gordy,

Its a molex connector and I think I have a bunch extra, I'll send you some if you need.

Gordy · « **Reply #49 on:** 24 Apr 2005, 07:32 pm »

Hi Josh,

If I paid attention half as much as I jabber I'd have seen your part # on the first page... Angelo pm'd me and I've them on the way!!! Thank you very much for your kind offer!

JM · « **Reply #50 on:** 1 May 2005, 05:18 pm »

After spending my whole Saturday filling up the chassis, my dual mono UcD400 amp is finished.
So far it is still break-in, but the initial impression is very favorable. IMO, much better then my fully moded Carver Pro ZR1000.
This amp is absolutely quiet, no hiss or hum, or any noise of any kind from the speakers. The Avel transformers are very quiet as well.
I'm just a little concerned about the temperature of the chassis plate where the modules are attached. I wonder if I should beef up cooling of the modules. The rest of the amp is very cool and the vast chassis provides good passive ventilation through the top and side holes.
Here are some pics (there are more in my gallery):

ken_diyzone.net · « **Reply #51 on:** 2 May 2005, 02:30 am »

Hi Julien.

What a good-looking amp! Can't wait to hear it, must bring to the next RAVE. Should have drilled two holes on the front plate for two LEDs.

I can see putting two 2x3 (or something that size) heat sink on the out side of the chassis for some more heat dispersion.

Regards,
Ken

JoshK · « **Reply #52 on:** 2 May 2005, 02:41 am »

Very nice work Julien! You have a cap across the AC inputs of your bridge rectifiers as well as around the bridge. Did you experiment and find that helpful or did you read it somewhere? Just curious. I read that that works but wonder if you have empirically confirmed that or not.

Very nice layout! If you find the temperature of your UcD modules is too high, PM me and I will point you to the source of some nice small heatsinks that may help.

What PSU caps did you use? I am always curious. Besides the initial ones that I ordered in teh initial post I also have ordered a slew of Nichicon KG Golds and other caps to experiment with. I always wonder what others have found good.

I like the nice DIYZone.net chassis!

JM · « **Reply #53 on:** 2 May 2005, 08:43 pm »

Hey guys.

Thanks for the nice comments.
The heat could be worse, but I feel that a heat sink would help. Right now, I don't want to leave the modules ON all the time... I was thinking about adding a thick (5mm or so) aluminum plate for each module to the back of the amp.
The main PS caps are Panasonic TS-UP 6800uF/100V. The PS differs a bit from my original design in the sense that the main caps are larger, and I added a snubber circuit after the main caps. I used a 1 ohm Mill 12W resistor and a 0.27uF film cap. I still have to play with different cap values...
I have 0.1uF film caps across the transformer secondaries to add a bit more AC filtering. It was suggested in Dejan's PS article. I tried that first in my CD-PRO2 with very good results. The sound was much better focused. I also tried that on my Carver, but I used a bigger cap, 0.47uF was what I had. That had a similar effect, but I feel 0,1uF is a better value for this application...
The chassis is great. Everything fits in and it has very nice connectors. The speaker biding post are really massive... I just have to silk screen something like "Class-D stereo audio amplifier". LED's on the front plate would have been nice too, but I was too focused on the inside layout.
We have to get together and listen to this baby and compare with other amps.
I'd be curious to see how it fairs against other tube, SS, and class-D amps...
It sound really powerful...
Josh, I'm PMing you for the source of the heatsinks.

Gordy · « **Reply #54 on:** 3 May 2005, 03:47 am »

Here's my slightly different take on a UcD amp! I'm using the battery power supplies Occam pointed out to us some time back, but re-wired for +/-48v. Unfortunatly these are no longer available as somebody bought the remaining 80 supplies!!! Because I'm using the power supply chassis's, I'm pretty much limited to this temporary set up until I've made my wooden wraps/covers to add some more height and allow better placement of the modules and more permanent wiring... The rest of the amp and charging system can be found in my gallery on page 24.

Occam · « **Reply #55 on:** 3 May 2005, 04:25 am »

Beautifully done Gordy!!!!
and a great way to save bucks on transformers, caps, chassis, AND get better sound to boot.

and to all those folks who dicked around thinking about buying those battery packs for $25 each, until it was too late and they were all gone -
YOU ARE ALL A BUNCHA DUMBASSES!!!!:o

Now Gordy, don't be modest; tell the folks how incredibly good it sounds,

Well done dude......

EDIT - Included within that characterization as DUMBASSES, I'll have to include myself

. I initially bought 2 of the battery packs, and when I ultimately went back to buy 6 more, I found they were gone.....so that the shouting is really aimed at myself.

Gordy · « **Reply #56 on:** 3 May 2005, 05:12 am »

Thank you Occam! Still a work in progress, but getting there. Actually the battery units were a whoppin' $61.00 each after shipping...

Being highly biased, I think they sound wonderful, even at 50 hrs. (about 10 or 12 in this configuration), a tad hard at higher db's with one cd we (Nature Boy and I) listened to of hard hitting jazz piano! I did get burned by buying the modules from the NA distributor instead of from Hypex, as I didn't get the 8420(?) buffer chip

I haven't tried adding any caps or snubbing as yet.

I'm getting 150w at a full 54v charge and after a 12+ hr. run I'm still at 49-50v / 130w... Not too shabby, I don't think! Re-charging takes less than 15 mins. Going strictly by what I found playing with chip amps, there is no down side to the batteries, just a eerily quiet amp! I found them to be quiter/more finely detailed than my mono blocked Avel, Fairchild and Nichicon Gold KG capped supplies being fed by a 2.0+ BPT. Pretty cool.

Occam · « **Reply #57 on:** 3 May 2005, 11:47 am »

Gordy,

Indeed, the cost of shipping added substantially to that nominal $25 price. But where else are you gonna get 4 Panasonic 12v 7.2ah SLA batteries, a charger and a chassis for anywhere near that price?

You are entirely too modest and honest. That 150watt/channel is into 8ohms, and the 'standard' of quoting into 4ohms, gives a solid 300wpc.

As you seem unwilling, perhaps Nature Boy will chime in with his comments on your amp vs. the latest amp du jour to which you guys compared. (damping factor of 4000 my arse! Perhaps into a resistor. A pissant powersupply is still a pissant powersupply, no matter what disengenuous marketspeak is used. An effort to publically polish a turd.....)

JM · « **Reply #58 on:** 3 May 2005, 03:37 pm »

Gordy.

Very nice amp.
It would be interesting to compare our amps and test how much of a role the power supply plays on the sound of these class-D modules.
My amp still needs a lot of break in time...

speedcenter · « **Reply #59 on:** 3 May 2005, 05:16 pm »

Quote from: angelo

Quote from: speedcenter

Neutrik Powercon - absolutely the best for safe high voltage connections. These aren't cheap, though - male and female combined for a single +/- link will be about $1.

I used them in the past for my DAC to connect to external battery and am currently building a preamp with remote Power supply where I'll be using them again. They lock securly in place so there's no risk that the wire will get pulled out by accident while the music is playing

Peter

where can i get ...

sorry typo or something puked in the forum here ('cause I didn't post twice...).

$10 for male plus female is about what you have to budget for one connection. I just got 4 of these sets for a tube preamp with external power supply from mouser.com

Peter