pedal only works when guitar vloume is on 7 ?

Started by joeboo88, September 16, 2010, 11:45:21 AM

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joeboo88

i just built a clone dod 250. the volume and gain both work, but isnt very loud. The pedal only works when my guitar volume is on 7 ?    anyone come across this. I am new to this sport.

JKowalski

You mean on 7 and above? Is your guitar signal just really weak? Distortion pedals need a certain amount of signal to distort, though usually it doesn't take much Maybe you messed up somewhere in the build and as a consequence the gain was reduced? Are your resistors the right values?

If it's just on 7 only that's pretty strange.

joeboo88

yes volume only works on 7 (guitar) cuts out at any other setting, i triple chk'd all the solder conections and i used the values Beavis audio said to use, maybe i'll have to start replacing resistors one by one? Oh i had to use a b100k volume on the effect pedal, whereas the schematic says a a100k... would this do it?

petemoore

  Sounds like the guitar volume is biasing the input...
  Do the Debug stick thread routine, then we can be able to work with the circuit.
Convention creates following, following creates convention.

joeboo88

yes i'm new and just read Aron's post about debugging, i have an old analog meter but should help me get the values, thanks i will start checking....what does biasing the input mean? dont laugh at me! har 

petemoore

  Specifically that everything that is shown on the schematic is represented by the circuit board, exactly.
  Generally that equates to popping into bias/performance parameters as soon as 'it' is located, identified and solved.
  DMM is much easier to work with, they are at various locations, best investment a debugger can make.
  I used a battery as a comparator with an analog meter to get an idea of where a voltage would put the needle, then chose the index [on the face of the dial] which was...right around 9v ! or 1.4v with a D cell. Referencing a known voltage made the meter reading [and finding the relevant settings and dial-index] easier.
Convention creates following, following creates convention.

joeboo88

thanks for wasting time on me.....i thought to my self, "okay dummy you've built a grand total of three pedals, and have been lucky so far, start over and quit wastinf peoples time. I found the problem b4 i left to but a dmm, which i will anyways....on the input jack i had the - batt lead and the input from pedal backa%%wards....i fixed and wow what a sound. thanks again guys