Changing gain pot value in Boss SD-1 mod

Started by SpikeVelvet, January 24, 2021, 11:04:57 AM

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SpikeVelvet

I am not sure I really understand how pot value works for the gain control in a circuit. I'm hoping somebody can explain like I am 5.

I modified an SD-1 and changed R6/C3 to give the pedal more gain. It still has the stock 1M pot. I have all the gain I need at about 12 o'clock. Am I correct in assuming that if I change out the pot to a 500k it will have the same amount of gain at max but a more useful and precise sweep of the pot?

Also, isn't there a way to strap a 1M resistor across the terminal to have the pot behave like a 500k?

Thanks,

Kevin

bartimaeus

why not just tweak R6/C3 to give you the amount of gain you want at max?

POTL

the gain will decrease by 2 times. if you are not satisfied with the smoothness of the adjustment, check what is the characteristic of the potentiometer, it is indicated by letters, usually A, B, C, W. you need a potentiometer with the letter A

antonis

Quote from: bartimaeus on January 24, 2021, 11:45:50 AM
why not just tweak R6/C3 to give you the amount of gain you want at max?

That..!!  :icon_wink:
(more cheap than preplacing pot mod..)
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

iainpunk

i'm 95% sure its a log pot, so in the middle isn't actually 50% resistance, more in the neighborhood of 35% resistance. if you are on a spending spree already, i suggest getting a TRIM pot of 2M and put it parallel to the gain pot, set the outside knob to max and turn down the trimmer resistance until you have the desired max gain.

cheers, Iain

edit: 1300th post  8) :icon_exclaim: :icon_lol: :icon_wink:
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers