Duplicate pedals don't sound the same?

[BAARON]

- pots vary, as mentioned.  Not sure whether the degree of variation has any correspondance with diameter (i.e., are 24mm pots more "precise" and on-spec than 16mm?)

I don't think so.  I use a lot of nice-ish CTS 24mm pots in amp and guitar builds/repairs as well as the cheapo Alpha 16mm pots in my pedals and guitars, and I find that both are pretty inconsistent... Usually within about a ±10-15% margin, but I've seen farther.  I think the advantage of the larger pots is usually wattage: the 16mm Alpha pots are only 1/4 watt AFAIK, but the 24mm are 1/2 watt.

[shimster]

I'm thoroughly enjoying this thread! Thanks for all the entertaining anecdotes and advice! I'm glad I check all my resistors with a multimeter instead of always relying on the stripes.  How can I check capacitance? With my ears?

[mharris80]

Ever played an old Marshall?  Or more appropriately, ever played more than one old Marshall of the same model from the same year?  I'm convinced that guitarists have literally been driven insane trying to find that "perfect" plexi head.

[BAARON]

How can I check capacitance? With my ears?

A Nice DMM should have a capacitance setting.  Mine does at the shop and I love it.  The one at home... not so much.

Ever played an old Marshall?  Or more appropriately, ever played more than one old Marshall of the same model from the same year?  I'm convinced that guitarists have literally been driven insane trying to find that "perfect" plexi head.

Yeah.  Let's just keep walking past the crazy plexi hobos for now.

[aron]

> there was a mid range tone in both but the original ts9 has a "back" low end i can't explain.

I would look at the capacitors in this case.

[shimster]

Hi guys,
  Great news! I swapped tubes in both my built pedal and the breadboard copy and revealed that the two batches sound completely different! I'm not entirely sure how to handle this though. I guess I'll measure voltages on the good tubes and try to bias the circuit with the new tubes.  Should I use trim pots in place of the grid leak resistors?
-Dan