On 13 February 2008 at 12:45, Joe Hartley <jh@xxxxxxxxxxxx> 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 _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
