No Sound from Hypex UcD180 / SMPS400

[r100]

Hi all,
I've put together a build with two UcD180HG amps and one SMPS400. I connected everything as in the diagrams found on this forum but I guess I have messed-up somewhere because there is hardly any sound from the amp. Turning the volume up on the pre-amp doesn't seem to make any difference. I have checked soldering, etc., re-checked the diagram but still no success.

The amps are wired with RCA plugs.

Diagrams used for wiring in post no. 6
http://www.diyaudio.com/forums/clas...-auto-amplifier-enable-amplifier-standby.html

Any help greatly appreciated
thank's

 

[r100]

Update: I've re-wired pin 4 (J4) to the GND. Sound is a little louder but still very muted.

HELP ;-)

thanks

 

[r100]

Cookie box amp

I have rechecked all connection. The amp is wired the same as the first picture. On the second you can see the actual amp. Sorry, it looks like a birds nest but the connections are good.

 

[Davey]

I'm unclear why you've wired UcD pin 4 to ground. Both of those should go to the yellow wire on your SMPS and nowhere else.

The blue lights on the modules are turning on? You've checked for +/- DC power from the PS module?

Since you're using unbalanced inputs you should be on Pins 1&2.....Pin 3 should be open.

Dave.

 

[r100]

Success, it finally is working !

I'm unclear why you've wired UcD pin 4 to ground. Both of those should go to the yellow wire on your SMPS and nowhere else.

The blue lights on the modules are turning on? You've checked for +/- DC power from the PS module?

Since you're using unbalanced inputs you should be on Pins 1&2.....Pin 3 should be open.

Dave.

Thank's for that. Pin 4 (UcD) is back on the yellow wire on the PS. That was the initial setup I had. Not sure what you mean by Pin 3 open ? I have the shielded cable from Hypex which has a shielding and two cables in the middle. One of them is on the + of the RCA and the other together with the shielding on the chassis. I think this is what Hypex recommends.

In the meantime ....

In a last resort attempt I took the whole box upstairs where my main stereo is and hooked it up.. guess what.. it works !

I still have to figure out what was causing the problem, but I suspect that it was either a faulty pair of (old) loudspeakers I was using for the test or the LS cables...

Best to all.
R

PS will post some pics of the build when I get the enclosure.