Volume pot value?

[MAO]

I converted a Plexi Drive to run off 18v. The output volume increased quite a bit, so much unity gain is between 9 and 10 o'clock on the volume knob. Just past noon, it's already too loud...if there can be such a thing.

I replaced the 100k pot with a 50k so the range of the control would be more useful. Not sure if dropping down to 50k at the output has a negative affect, I didn't notice any.

Then as an afterthought, I'm wondering if it would have been better to put a 50k resistor between lug 3 of the new 50k pot and the pcb to maintain the 100k total resistance. I'm thinking full CW with this setup would be like 2 o'clock on the original 100k pot. Seems to make sense.

Any thoughts before I dig back in to this one?



   

[Frank_NH]

The issue of how to size the output pot is an interesting topic.  My understanding is as follows (some please correct me if I'm off base).

Think about the volume pot as a separate stage in your pedal chain:

Pedal --> Volume Pot --> Amp or other pedal.

What matters from the standpoint of not losing signal strength is to maintain a low impedance output coupled with a high impedance input.  If your amp (or pedal) has a high impedance (say 1M ohm), then anything lower like 100K and below will work.  However, if the output impedance of your pedal circuit is largish (lets say 10K - 50k), then you won't want to go much below 50K.  It all depends on the circuit.  If you put a buffer at the end before the output pot, I suppose you can go small e.g. 10K.  

I think 100K has become a "standard" output pot for general pedal circuits because it's a good compromise between the output of the pedal circuit and the input of the downstream device (e.g. amp).