i have a danelectro daddy-o pedal that has been steadily losing
gain as time has progressed. i now have to turn the volume up
almost all the way to get it to be balanced with the bypassed stage.
what's up? any suggestions or clues of what that might be?
No, please, let ME be Frank !!!
Unless you can figure out how to fix it, by repairing some non PCB related problem...the mini boards wires are so tiny/tight...limited returns on fixing efforts....since it's dying you could try [I haven't read that it's categorically impossible, but look how small...].
Good News is there's a veritable plethora of EZ OD builds that OD real nice, in myriad different ways...and...of course...Can be modded, tweeked, chained, Q'd...and debugged.
Not to insult your troubleshooting skills, but have you checked the battery?
it's powered by a wallwart, ive tried different ones with the same
results.
I wonder if the pot shaft has failed to turn the "innards" or something. They use some pretty cheesy pots on those Dano pedals.
You may want to take an audio probe to various parts of the circuit and see if you can track down the source of the problem.
If you have extra TL072 op amps around, you may replace the IC in there.
I have mods for this while you're at it and if you're interested in them:
http://www.geocities.com/transmogrifox/daddyo.html
It produces a much more open "bluesey" sound with these mods. Try various op amps, especially if you can find some high quality CMOS IC's somewhere. I also recommend an OP275, TSH22, or MC33078. The TLC272 has a nice sound, but it's a little muddy and it isn't known for it's low noise characteristics.
But for figuring out what's wrong, I'm not sure where, exactly to start. Another thought I had is to measure the power supply voltage at the supply terminals of the opamp IC and at "V/2" to be sure it's all good. A failing IC, or insufficient power could certainly cause this, and it may be possible that something is deteriorating in that 100 ohm resistor in series with the power supply.
Those pots they use are available from DigiKey. I ordered a few. They seem to work well, but they're not very durable.