The Watering Hole

Hi all!

I've a true bypass overdrive pedal that is producing something like a countinous sine wave noise when turned on.
No matter which one of the three knobs I turn up (drive, volume, tone), the "beast" starts to squeal when the knob position is more than zero!

When the pedal is turned ON with all controls set to zero, the noise starts if I turn down the volume on the guitar... (WTF ??????)

What I've tried..
- Changed the cables, no differences..
- Using only amp, pedal and cables (no guitar) the noise is still present.
- Changed power supply, no differences
- Placed a non true bypass pedal before the screaming OD...BINGO!! The OD is perfectly quiet and it works as expected!

I purchased new this pedal a long time ago and I've never noticed this issue also using only this pedal between guitar and amp....

Any idea???

Ciao
Marco

Sometimes older pedals will do that.  If you mix them with certain pedals they won't because of something in the other pedal.  Sometimes even true bypass pedals will not play nicely with other pedals.  

Quit buying Behriner pedals! HAHAHAHAHAHAHA

A) What is the overdrive?
B) when you say "non-true-bypass" pedal in front of it, what you mean is "buffered" pedal, I assume, like an 808, or a boss pedal? The obvious fix, besides replacing anything broken in the pedal, is to add a buffer to it...

If I know what kind of pedal it is I can probably give a little more info.

Fenderbender you're not too far from the truth! :)

Charger, the OD is just one of the thousands TS808 clones (JOYO vintage overdrive).
The pedal I placed before the OD is a buffered TS9 (turned off)....I don't understand why it's working only in this way...

Cheers

Joyo Vintage overdrive is a TS-808... minus the buffer. Putting the buffer in is not simple because the jacks are board-mounted, which means you have to cut the wires from the switch to the board and get the buffer in the right spot.  Alternately, you can buy a buffered 808.  I can't tell you why it started squealing or which parts to replace, for that you'd have to trace the circuit with an audio probe... you're talking about a cheap pedal that probably isn't worth putting that much work in to unless you absolutely love it. I'd guess a transistor, but there are no transistors, because it's unbuffered. So then I start looking at cold solder joints, a bad cap, or a short.  

My Delaveaga Drive has true bypass but is buffered when on... All the standard TS808 sounds as well as some killer switchable mods...

Thank you Charger!
It's a cheap pedal so I don't care too much about it...

Ciao
Marco

Yep, at $32 I'd just replace it and not worry about it. If you need a sine wave generator, you've got one now.