Turbo Rat self oscillation.

[Bipolar Joe]

I've had one of these for a while, and it's really buggy. First off, is it supposed to self oscillate like crazy? The pitch changes with the distortion knob.

Here's a small clip of the problems. Warning, it gets loud.

At the beginning, the pedal is on, everything is up all the way, but it sounds like this.

At 12 seconds, I turn down the distortion, turn it back up, and at 19 seconds, turn down the volume, and back up.

At 26 seconds, I squeeze the board length ways (Broken trace or dodgy solder?).

31 seconds, the self oscillation, 39, turn the distortion knob, which changes the pitch.

50 seonds, turn down the distortion while the guitar is playing, it acts like a volume knob.

Any help would be really appreciated. Thanks, guys!

[GGBB]

Not sure what kind of an answer you are looking for, but I can tell you there is something wrong with your RAT. Bad solder, cracked board, dodgy pots, loose wires, shorts, ?, ... something seriously bad - it shouldn't do those things.

I have a Turbo RAT but can't say I've ever turned everything all the way up, so whether it should self-oscillate under those conditions I don't know. 

[GibsonGM]

Hi Bipolar....you need to do some debugging.  I believe something is loose...bad solder joint or a broken wire, etc. Even one bad joint can do all that, and more.

When this happens, we have to look at EVERYTHING, even to the level of using a magnifying glass.   The sound, when it works, sounds ok...the oscillation can be caused by a number of things.

Provided it's assembled right, you'll get oscillation due to unshielded input wires, wires passing over each other too closely and not at right angles...and often, a high gain distortion simply WILL oscillate if you have it maxxed and are not playing.    They tend to be unstable.

Let's find the wiring/solder problem first!  Go back thru the schematic vs. what you have on the board, be sure everything is soldered up nicely (sometimes, powering up and wiggling wires with a pencil etc. can point to a loose wire).     

- Is this all set up with jacks and switches yet?  I test mine before wiring up the offboard stuff to be sure it's ok first.
- What are you powering it with? (battery or wall wart....battery is good for testing)