Forum vibe fv-5 rev2 (need help to find bug)

[Frenchy]

Hi guys,

I'm french so excuse my future language mistake !!!

I come here to request your help cause i have built a univibe pedal : forum vibe type fv-5 rev 2.
I find a lot informations for fv-5 rev 1a but not for rev 2.
So i wiring it as a rev 1a with cancel/bulb off, lfo led, etc.

My true bypass is ok.
my lfo led is ok and it change it speed light when i turn the speed bottom.
my volume bottom is ok.
i see a différence between chorus and vibrato.

BUT

The first problem : my bulb don't works... (and when i touch two legs of q14 the bulb stay really flashy, it's maybe a clue !!!)
The second problem : there is a lot of noise in my ampli when the pedal is on  (it change of noise with chorus or vibrato)
The last problem : when i bypass the pedal i hear the sound of my guitar as normal but the lfo led continu to flash and oscilate.

Wooa a lot of problem i can't solve alone, if you could help me it will be fantastic !

Ask me for more informations, and have a nice day 

Eddy the frenchy

[Kevin Mitchell]

I'd guess there's a wiring issue or a solder cross if you're getting bad noise in the signal. But that also could have to do with the power supply you are using (bad filtering). I could be wrong though I've never worked on a forum vibe.

The LED is still on when bypassed likely because the pedal is still getting power. This is normal with effects. You can rig the cancel function or part of the LED to turn off when bypassed.

I suggest you dig up sufficient information about the effect and how to debug circuits. Throw together an audio probe, grab a multimeter and explore the hell out of the circuit. Follow the signal with an audio probe using the schematic and wrap your head around the fundamentals of how a guitar effect works. Start at the clean input, follow the signal till it gets nasty. Whatever part/area you stop at is suspect to issues and should be observed further.

[Frenchy]

i think so for a bad wiring, i verifie all the solder and they looks ok.
the power supply is a 18V i have buy with the kit.
It give 17.8V with a multimeter.

Ok for the led, i understand 

And for your suggestion i look at all composent and i don't find any problem with the multimeter...
But i don't try with a audioprobe, i will make it.

Thank you kevin