Turbo RAT issue...

[heb9_28]

Hey, just wondering if any of the "tech" guys around here could help me out.

I got a Turbo Rat on trade from a fellow TBer and there's a problem with it. I actually had wanted one specifically because I had heard there were some good settings for a bit of soft "always on" grit. Well, with my particular Rat, as soon as the distortion knob is engaged it is full on, heavy distortion. When I dial it all the way down, the pedal is silent. There is no varying of degrees, it seems the distortion is either "on" or "off". The volume knob works fine and I'm not positive about the filter knob because I would imagine that the fact that the distortion is blasting would make it a little less responsive. I can hear some responsiveness, but can't tell how much. When I contacted the person I got it from (who is an avid TBer and consistent trader on the effects board with lots of positive feedback), he just said that he was trading the pedal for a friend and hadn't even tested it out so he didn't know that there was a problem when he traded it. Either that's true and its kind of shady he traded a pedal without knowing if it even worked, or it isn't true and he knowingly traded me a bad pedal. Regardless, I'm really not the type to get all fired up so I really just kind of let it go with an "oh well".

But my question is: Is there some way for me to tell what the problem is? Could it just be a bad pot that needs replacing? A bad capacitor, a bad chip? A simple solder touch up? Or is the thing just bust and not worth trying? Is there a way that I can visually diagnose the problem? I'm not a huge electronics guy but I can solder.

I really appreciate any help from you guys! Thanks in advance!

[G0rilla]

Open it, and check out if any of resistors is cut or removed. Sounds like mod i done to mine. I removed one resistor, so it has more bass and becomes less in your face. Distortion knob, when turned all they way down, acts the same - mutes the pedal. If problem is not there, check out overall circuitry (by matching the gutshots) If something is wrong, try to replace it with part in working one. If everything is original, try to change pot.
Thats all i can help with.

[rratajski]

Sounds like a bad pot to me, but dude, it's in the user policy that we can't sell/trade pedals that aren't ours. That's a big no-no on his part...

You might not be able to visually see an issue. I would bring it to a skilled pedal dude in your area to trace the issue.

[UncleFluffy]

Could be a bunch of things, but the first thing I'd look for is a broken solder joint. Sounds like one end of something has gone open-circuit (or been removed completely as per G0rilla's post).

[heb9_28]

Yes.

Under more careful inspection (and wiggling of wires while in use) I did find a wire that had become loose that was causing the problem.

Completely random side note, while searching online for a Turbo Rat schematic, I stumbled across this mod which I did and made me about 50000000x more in love with this pedal than I thought I would ever be. Is that the same mod that you're talking about? Having done that mod, the Turbo Rat is probably the best bass overdrive that I've used (granted, I haven't tried a ton of ODs).

Anyways, I do appreciate the responses and I'm 100% stoked with my pedal now. Thanks all.

[G0rilla]

Yes, it is same mod
Well, i wont say the best, at least for my ear, because it still "eats" a lot of bottom end. But i use it blended with low and low mid boosted signal, and it just works perfect for that snarling, gritty, ear-biting overdrive. Also it becomes a great volume booster when drive is set 10.30-11.00, and volume adjusted to situation - great tool if you play with tapping and need to be heard through 2 loud guitars

[rratajski]

The double resistor replacement mod is betterrrrrrrrrrrrrrrr: http://beavisaudio.com/projects/FKR/...htierMouse.gif

[benmoore88]

i have a modded RAT and it KILLS!! i blend it but i've owned HEAPS of bass dirt units and this is the one i use.