Kinda Odd Rangemaster Problem

[kurtlives]

Just finished a Range Master...very standard but switches to select input caps (0.047mF and 0.011mF) and transistors (OC44 and OC77).

Works fine except when I wanna use the OC77 and the 0.011mF cap. I get no sound.... I do get sound when I use the 0.047mF cap.

I know this is all vague but any ideas?

Thanks..

[petemoore]

  Audio probe...
  Or DMM to verify that the connections leading to each cap pass DC, and that these connections have little to do with ground [ie resistance to ground should equate to schematic value[s

[John Lyons]

Yes, It's got to be just a simple wiring/switching mistake.
Keep looking and it will pop out at you...

john

[kurtlives]

Thanks guys... I have been proding it over and "DMMing" it.

Pete arent those input caps blocking DC? How can I test that they are doing their job?

[petemoore]

  See if the meter 'beeps' across the cap.
  Or measure DC on both sides of the cap, the DC blockers should keep DC inside the circuit.
  ...put cap across a battery? see how much DC flows through it? look for voltage drop...never tried it ott I guess a good cap would maybe make the meter jump once when connected.

[kurtlives]

  See if the meter 'beeps' across the cap.
  Or measure DC on both sides of the cap, the DC blockers should keep DC inside the circuit.
  ...put cap across a battery? see how much DC flows through it? look for voltage drop...never tried it ott I guess a good cap would maybe make the meter jump once when connected.

No continuity across either cap.

I do notice now there is some farty volume swells when using the 0.0047mF cap and OC77.

[kurtlives]

Ok so now I have the problem when using either transistor.

I replaced the trimpot with a 51K resistor (like SBE suggested).... The sound it farty and swells.

There are two input caps wired in parallel. There is a switch to jumper one cap...