Rat Clone volume loss?

[Holydirt]

So, I built a rat clone using the tonepad layout. It worked fine for a couple weeks and I love it. But recently, when I turn it on, the volume starts loud, but gets progressively quieter the longer it's on. If I bypass, then turn it back on, the volume is normal again, but it gets quieter like before. Any ideas as to why this is happening? Thanks.

[petemoore]

Any ideas as to why this is happening?
  Lots of them. try getting it opened up on the bench, having Rat Clone volume loss, then debug it.

[wui223]

I am working on a RAT clone as well. But my problem is the Filter pot not working. I change another new 100k Log pot but the problem persist. Any idea?

[Processaurus]

I am working on a RAT clone as well. But my problem is the Filter pot not working. I change another new 100k Log pot but the problem persist. Any idea?

The filter pot could be shorted out, the following cap to ground might not be connected at one or both ends, or that cap could be the wrong value (too small).  The combo of the pot and that cap act as a simple "RC filter", if you want to look it up and learn about how it works, basically the cap to ground acts as a resistance (reactance is the word used in this case though) that gets smaller to higher frequencies.  So the high frequencies see a smaller reactance to ground, and get attenuated, leaving the lower frequencies.  The pot is set up as a variable resistor, so that sets the corner frequency of the cutoff, the bigger the resistor, the lower the corner.  I believe muzique.com has more info on the rat tone control.

As for the volume loss, thats weird.  Are you using the rat/millenium bypass that uses a transistor to light up an LED?  Dying battery? 

[wui223]

The Filter work at first run. then i put a SPDT to select different diodes combination. thats where the problem arise.