UCD Setup


2003-07-17 3:29 am
I have a pair of the UCD 400 modules on their way to me, now I need to know about power supplies etc..

1. Is a 500va 40volt toroid per channel OK? From what I can gather of the spec sheet it says up to 42Volts.

2. Can I go to a smaller VA rating, eg 300va per channel, or will this limit my output?

3. What is the minmum capacitance allowable for eack side? 20 000 enough?

4. Is a 10 amp Bridge rectifier per channel sufficient?

5. Finally, do the modules come with a basic diagram showing how to wire the transformer/rectifier/caps? If not can anyone direct me to one.

Thanks for any advice, Beau.


2003-02-03 8:39 am
1/2. The transformers that hypex sells for the UcD400 are 500va with 42V secondaries. Hypex says that these transformers are capable of powering multiple UcD400 modules...so, I would reckon you could use something around 300va per channel and be fine, or use one 500VA transformer to power a pair. More information from hypex, including a basic psu schematic, here:


The lower voltage secondaries (40V) on the transformer you mention will give you a little less output from your modules.

3. Seems to be some debate (big surprise) about how much capacitance is needed/ best, but judging from psu schematics at both lcaudio and hypex, it looks like 10000 to 20000 should be fine. More on psu stuff below...

5. If you hunt around in the drop down menus on the hypex.nl website, you will find a basic implementation diagram, including a basic psu outline. The one I found was here:


There is a more complex/ upscale? model that someone has created, which may be found here:


That last supply has received some attention on this forum recently, but you will have to hunt around for it. Also, try digging around in the "hotrodding the UcD" thread for other ideas.