Signal dropping out on Delta 1010 inputs?

[MikeC1980]

Hello my fellow Gearheads!

I wonder if anyone could offer some advice on a problem that has been affecting my M-Audio Delta 1010. This is the audio interface with a PCI card and a rack mounted breakout box with 8 balanced input TRS jacks and 8 balanced TRS outputs.

The problem I have is that the inputs pass signal unless the amplitude of the signal drops below a certain level for a while.

So a loud, fairly continuous signal like a Bass DI shows no problems. But with signals like tom mics or vocals that might have periods of quiet, the input signal drops out completely, and it takes a loud signal to 'break through' and start showing up on the DAW meters again. This is getting to be a problem as I have lost some good drum takes to this. It seems to affect all the inputs, though some more than others.

So does anybody know from experience what this could be?

I have tried using contact cleaner on the jack inputs, this doesn't seem to fix it. Another theory was perhaps the solder joints on the jack sockets are fractured, and need resoldering? The jack sockets are surface mount ones and are not attached directly to the rack case, all strain goes to the PCB.

Any advice would be greatly appreciated, thankyou in advance!

-Mike C

[acreil]

I think this usually indicates a bad connection. Loud signals tend to "break through" a surface oxide layer and establish a temporary connection. You're right to suspect the jacks. If the jacks contain switched contacts (which typically aren't "cleaned" by the action of inserting or removing a plug), that can also cause these problems... though I've really only seen that on insert jacks or other situations where the contacts are closed when no plug is inserted.

[crosscutred]

I understand the switches next to the sockets for +4/-10 can be problematic.

You could try cleaning them, or solder jumpers across them in the postion you use it.

If you have been plugging in and out alot maybe the sockets are becoming desoldered from the circuit board.

It's pretty easy to dismantle and easy to recap the power supply too, that is a common failing on these and worth doing tro eliminate future issues. (it's a bad day when it breaks down mid session, that prompted me to recap the other 2 before they failed)

[MikeC1980]

Hello, thankyou for the replies.

I did some mods to it a couple of years ago, I replaced all the PSU capacitors and then the signal path capacitors, with nice Panasonic FMs or FCs. I also removed one bunch of switches, I can't be certain if it was the output ones or the input ones, but I think it must have been the output ones. That would explain why the inputs are intermittent. Damn those cheap switches!

Cheers!

-Mike