UCD180 questions

[DVBjunky]

Is there any problems to use a B1 Buffer to feed the Ucd180 modules? Even OEM versions? Any clues or hints for me?

cheers

Aykman

[rtd]

UCD input stage has a gain of 4.5.
Buffer works well (i tried some) but there's not enough gain.
It depends on your preamp and/or speaker efficiancy

[orelli]

Hi Bruno, I just assemblate my UCD180 HG with regulators, but I've a problem. The amp works only at very low volume. I set my potentiometer at -50dB and the amp works, but at -40dB the the blue led turn off , and the amp is mute. Whit low level music I can hear at higher potentiometer position , but when the music goes up, the protection works.
I set the amp in this way( one channel):
trafo 2x30V
Ixys diode bridge
22000uF per rail
power supply voltage ,+/-42V DC.
Can you help me?
thanks in advance.
Best.

[tfboy]

I'm having problems getting some UCD180HG modules powering up.
The HXR regulators light up red, but the main blue LED stays off.
Can people confirm I have the power connected the right way up? The datasheets are confusing and have incorrect J pinout numbering so I want to be sure I have them the right way round.

BTW, I've also connected the yellow wire from SMPS400 to amp enable pin (pin 4 of Molex) but no joy. I've confirmed the wire shorts to ground after SMPS powers up and I've tried manually grounding pin 4 of the molex, but still no blue LED.

I've emailed Hypex support and speaking with them, but wanted to check with the community too

Here's a photo of my connections. red is positive, blue is negative, black is ground.

[koldby]

Try to apply some signal or put a load on the speaker terminal. Sometimes the UCD modules does not start without.

[tfboy]

I just found out the problem: the molex KK connector was wired round the wrong way!

I don't know if there is a standard for which end of the connector is pin 1, but I had a "1" marking on my connector and used that. I've only just realised that the illustration in the UcD documentation has pin 1 at the other end!

All looking blue now. Just rewiring the connector and will test in a moment

[tfboy]

Hmm, amps now appear to be working but I have terrible ground loop buzz.
I want to have two inputs: one balanced XLR straight into UcD module, one unbalanced RCA going through a 50k pot to act as volume control.

I've attached a drawing of how it's wired up.

The buzz seems to come and go as I move wires around, or move my hand near the selector. It's really strange. I've double checked my wiring but cannot see anything obvious.

Any ideas?

[koldby]

As I see it :
In pos 2 the right channel red (now wired to 5) should go to 8 and 5 and 11 should be grounded.
If you use pos. 3 to mute the hole thing, 3, 6 ,9 and 12 should be grounded.

[tfboy]

Whoops, yes, you're right.

Updated drawing attached.

I've started rewiring it all, and it's better, but I still have a problem, although think it's related to the pot...

[koldby]

Did you ground the potmeter?
That is the metal part of potmeter?