Author Topic: Problem with cloven hoof  (Read 398 times)

whomeno

Problem with cloven hoof
« on: September 20, 2021, 03:46:17 AM »
built it and it works but, I don't get any volume till 3/4 tur4n of the volume pot. changed pots twice. same thing. I am sure all parts are right value. checked for shorts. none that I can see. The only thing I changed is I used mpsa14 instead of mpsa 13 for Q2 and Q3 .help please.
voltages
Q1  E  0   B  .65    C  3.78
Q2  E  0   B  1.0    C  5.86
Q3  E  0   B  1.0    C  5.70
Q4  E  1.12  B  1.70  C  3.73













Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

anotherjim

Re: Problem with cloven hoof
« Reply #1 on: September 20, 2021, 05:33:13 AM »
If it's completely silent until the output volume is turned up close to max, it hints the problem is off board. If you wire a spare jack socket to the pot lugs 2 and ground (bypassing all the stomp switch connections) how is the output then?
Croeso i Diystompboxes.

I have no April 1st project

whomeno

Re: Problem with cloven hoof
« Reply #2 on: September 20, 2021, 05:52:56 AM »
anotherjim
 I built a pedal test box, that I use to test every thing before boxing. I am going to do a probe again to see where I loose the volume.
will get back with the results
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

whomeno

Re: Problem with cloven hoof
« Reply #3 on: September 20, 2021, 05:59:22 AM »
ok from Q2 to C7 good tone from C7 to R14 good tone on the other side of R14 8.2K I loose a lot of tone. it is cut in half
Gear as of now
Gibson 2017 Les Paul Tribute T
Epiphone Les paul Special (upgraded)
Marshall DSL 20 Head
Peavy Valve king 20 W
2 X 12 Cabinet with celestion vintage 30 & celestion G12T-75
And a lot of pedals

danfrank

Re: Problem with cloven hoof
« Reply #4 on: September 20, 2021, 10:26:37 AM »
I don't know if you've done this already but get a magnifying glass and check the solder side of your board for solder bridges and stray copper making an errant short somewhere. This is usually the culprit with vero board builds.
Also, check R15-R18 and those 2 LEDs in the feedback loop. Make sure that 100k resistor is 100k.
One more thing, and I don't know if this matters in the circuit, but the two middle transistors are specified as germanium NPN, it looks like you're using silicon on those 2 spots also.
« Last Edit: September 20, 2021, 10:32:15 AM by danfrank »