Tommy - Pot substitute

[jakebrown1989]

Hi all,
I am building a Tommy overdrive (revision 11.04.17 2017).
It calls for a A10K for volume and a B1M for gain.
Would it be acceptable to use a A500K for the gain and a B25K for the volume?
I would rather not have to place another order for parts at the moment.
Please let me know your thoughts!

 

[phi1]

Both will work. If it were me I’d use A-taper for the gain even if I was using 1M. A-taper should be much easier to dial in low gain. 500k will have less available max gain. Personally I think this is ok because I tend to think the Timmy circuit is happiest set as a low to medium gain drive anyway. And from 500k to 1M isn’t as drastic as it seems, mostly just more compression.

The volume pot is a voltage divider after a buffer, so the value doesn’t matter too much (anything up to 100k should be fine, higher than that you risk interaction with the input impedance of the next pedal or amp). B taper may be slightly harder to dial in right where you want it, but I think you’ll be just fine (I’ve used B taper for volume several times).

 

[paulc]

Hi all,
I am building a Tommy overdrive (revision 11.04.17 2017).
It calls for a A10K for volume and a B1M for gain.
Would it be acceptable to use a A500K for the gain and a B25K for the volume?
I would rather not have to place another order for parts at the moment.
Please let me know your thoughts!

The Timmy never used a B1M. It should be Audio taper. A500k is fine - that's what was used in the original Tim and now the V3. For the past several years the vol was a A25K pot with an 18k resistor soldered across input to wiper. This altered the taper to put it at 25% at noon.

PaulC