Hi everybody,
I've just built a Barber Silver LTD.
It works, but Drive and Tone Knob have no effect on sound. It sounds like Level and Tone knobs are maxxed out to 10.
Volume pot and trimpots work. When i touch drive pot's lugs with my hands it shuts completely (rebegins to sound when i take them off)
I've tested the voltages, checked the boards, substituted the pots and the IC but didn't resolve the problem.
What's the problem? what can I do to solve?
Thank you!
IC: TL072
pin 1 4.35V
pin 2 4.52V
pin 3 4.31V
pin 4 0V
pin 5 8.90V
pin 6 4.55V
pin 7 4.52V
pin 8 4.01V
Didn't modify any value.
Here's the schematic
http://www.barberelectronics.com/images/barbersilverltd.jpgThis is the layout and pcb I used
http://www.madbeanpedals.com/builds/ltd/BarberLTD_rev1_TN.gifThank you!
Andrea - Italy