[LAU] Multiple M-Audio Delta 1010s

[Kevin Cosgrove]

On 13 February 2008 at 12:45, Joe Hartley <jh at brainiac.com> wrote:

kc> Could you share with us the symptom and specifics of the solution 
kc> involving replacing a cap?  I'm wondering if the noisy channels 
kc> problem mentioned here a couple of times is related somehow.
> 
> Heh - I just Googled to see if I could find a good link to describe
> the process and the first link I come up with is a post of mine to the
> Planet CCRMA list about the problem!
> 
> My symptom was a horrendous buzz on all 8 output channels. 

One unit I had started having troubles with buzz on the output 
channels a few months after I bought it.  At first power cycling the 
unit would get it to behave, and at first it was only a few channels.
Eventually it was all channels, and I couldn't get it to behave.
I returned the unit under warranty and got a replacement.

> When I took
> apart the breakout box, I saw a quadrupling circuit on the left hand side
> of the bottom board (toward the front of the case, underneath the small
> board that's on top) that had a couple of oozing caps.

That happens more often in electronic equipment than the public generally knows.
Remember the laptop battery recall from months ago?  I've seen quite 
a few recalls for capacitor problems over the last 3 decades of 
working in the electronics industry, first as a part-time soldering 
and assembly person, and now as an analog IC designer.

> I replaced them with 2200uF 35v caps from DigiKey:
> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=493-1879-ND
> 
> If you've ever done electronic soldering before, it's a trivial procedure:
> remove the 2 small 2200uF 25v caps and squeeze the larger caps in there.

Doesn't sound too bad.

> The 35v caps are recommended, it was the underspec'ing of the caps that was
> causing the problems in the first place.

Did you measure the voltage somehow, or did you get documentation 
from M-Audio somehow to figure out the new recommended voltage rating?

Excellent write-up.  Thanks a bunch!

--
Kevin