2 Pedal Builds and same Issue

[yalesmith]

I  have a tube screamer clone and a guvnur clone from GGG and they have the same issue which is a loss of volume when engaged.  The volume dips approximately a third, all the voltages are correct so i am baffled.  The only commonality is i am using solid core wire and the same switching diodes.  Any theories or help will be appreciated.

Thanks

[MikeH]

1)  Have you tried going through the circuit(s) with an audio probe? 
2)  What kind of diodes are you using?  It's possible they are clipping too much, and that's why you are losing signal; I know the Guvnor is meant to use LEDs, which clip a lot less than say, germanuim diodes.  Germanium diodes will not work in a TS without some added gain make up.  If your using different diodes than the schematic calls for, I'd try the correct ones first.

I'd post the "Debugging" list here too.

[Hides-His-Eyes]

1)  Have you tried going through the circuit(s) with an audio probe? 
2)  What kind of diodes are you using?  It's possible they are clipping too much, and that's why you are losing signal; I know the Guvnor is meant to use LEDs, which clip a lot less than say, germanuim diodes.  Germanium diodes will not work in a TS without some added gain make up.  If your using different diodes than the schematic calls for, I'd try the correct ones first.

I'd post the "Debugging" list here too.

An LED lets far more signal through than a germanium diode.

Is the 1/3 drop with the volume at maximum?

[yalesmith]

I am using both leds and in4148 diodes, with the options to switch between the 2.  I do have an audio probe, should I have the pedal powered and i should be looking for volume drop?  Right now the volume drop is so significant that the pedals are so unusual....Witht the ggg guvnor i am using the 4 diode option and 2 leds...

[R.G.]

Both pedals have a common problem, right?

What else is common between the pedals?

[Fender3D]

Both pedals have a common problem, right?

What else is common between the pedals?

You mean builder aside?

[yalesmith]

same solid core wire, switching diodes and that's about it....

[Fender3D]

If the pedal works, level aside, you'd better follow the signal with the probe (a scope would be better) and check where it drops down

BTW
if it works, level aside, the culprits are always the same:
bad solder joints (hmmm joints.... [homer_drool_smile.gif]), wrong values, reversed caps...

They or the butler...

[yalesmith]

OK i have an audio probe and no idea how to go about using it.  Where do i start?  I really don't read schematics (i am trying to learn) well at all...If someone can give me an idea where to start at switch then to r1, r2 , c2 etc.  i will be very great full.

this is the schematic 

http://www.generalguitargadgets.com/pdf/ggg_mgv_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

Thanks!

[Mugshot]

check your pulldown resistors. check to see if it says 1M or up, or any high valuein the kilo range, and not in the ohm range.

[yalesmith]

not to sound stupid but what are pull down resistors?  Also, just while i am at asking stupid questions, if an resitors is labeled 680e, that is the same as 680 ohms. and not 680m ohms

[Keppy]

The pulldown resistor is a high-value resistor to ground and is usually the first thing in the circuit after the input.

Most resistors are color coded, not labeled numerically, so I'm not sure what your "680e" refers to. Are you sure you're looking at a resistor and not a capacitor?