thor build very noisy... possible solutions?

[beatnik]

I've built this awesome pedal (thanks ROG) but it still need some debugging.

In fact there is a loud noise, wich becomes louder when i don't touch any string.

I thinked it could be my cheap power supply, but also use it with a dr.boogey (wich is a similar circuit and very noisy too...) with zero hiss or hum.
Resistor are carbon film type, maybe metal film 1% would reduce noise?

I use shielded wire for the gain pot and for the wiring going from pcb to 3pdt and from 3pdt to in/out jacks (as i did on my dr.boogey)
and biased Q1 and Q2 as indicated in the original schem.

Have you had the same problem and fixed it? any suggestion please?


Giacomo

[bkanber]

In general, noise problems are usually:

1) Something not grounded.
2) A short or solder bridge.
3) Sometimes, a broken trace.

All that really can be said is to double and triple check everything.

Good luck!

[plankspank]

In fact there is a loud noise, wich becomes louder when i don't touch any string.

Definitely sounds like a ground problem. Make sure the in/ out jack grounds are grounded to the PCB board ground; and these all should be tied to the enclosure ground also (along with the pot housings). Do you have this in an enclosure yet? Try it also powered by a 9V battery....

[raulgrell]

It does in fact sound like a ground problem. Make sure everything is well soldered, that your caps are good and your FETs are biased properly.

I wouldn't rule out the problem being in your guitar. Have you ever had your guitar wiring checked/pots replaced? If the guitar is old, the electronics start to go a bit off inside the guitar. How loud is it when you are touching the strings?

It might also be in your pickups - are they shielded?

[beatnik]

i checked all the wiring and finally i'm sure it's ok

i tried to power it by a 9v battery and no more noise!

so i think i have to buy a decent power supply.

thanks everybody for the help

[MadMac]

Hey beatnik

Does your thor oscillate when playing individual notes i.e. sound as though the distortion is a little like a vibrato sound happening as well?   Mine seems to do this and I haven't worked out why as yet.

[frankclarke]

Could be an unshielded guitar.

[beatnik]

mad mac i don't have

the only other "strange" thing of my thor is that the bright switch doesn't have much effect with high gain settings.

but that's not a problem because the highs are enough for me.

I am thinking to box it with a dr.boogey with a common versatile eq (maybe tonemender from rog)