Propolis volume knob or trimpot

Kroars

Well-known member
Hoping one of you gurus can help confirm: Would I be correct in thinking that I could either replace R17 with a 500k trimpot or replace with a 500k linear pot for volume control on this board?

Thanks!
 
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fig

Village Idiot
KAY%2BFUZZ%2BSCHEM.jpeg
 

thesmokingman

Paid Hater
the 100K on the kay fuzz tone is more or less the 330K R17 of the propolis (corrected)

now let's get specific ... the propolis is bleeding off more signal to ground than the kay fuzz tone and lowering R17 would continue to do that. Placing a trimmer there wouldn't be a very effective volume control as there is always a signal path to the output with 0R resistance

The more traditional route would be a volume control like the fuzz face where the pot is a voltage divider going from bleeding all signal to ground (0R to ground, 500K in series with signal) to passing all signal out (500K to ground, 0R in series with signal) ... in order to do that you'd need to place such a pot on the output and remove R17 (which would be parallel to whatever resistance to ground the volume control presented)


and since we're being thorough and you may get curious ... go watch a video of a kay fuzz tone if you're wondering why union tube got rid of the rocker-based tone control
 
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Kroars

Well-known member
the 100K on the kay fuzz tone is more or less the 33K R17 of the propolis

now let's get specific ... the propolis is bleeding off more signal to ground than the kay fuzz tone and lowering R17 would continue to do that. Placing a trimmer there wouldn't be a very effective volume control as there is always a signal path to the output with 0R resistance

The more traditional route would be a volume control like the fuzz face where the pot is a voltage divider going from bleeding all signal to ground (0R to ground, 500K in series with signal) to passing all signal out (500K to ground, 0R in series with signal) ... in order to do that you'd need to place such a pot on the output and remove R17


and since we're being thorough and you may get curious ... go watch a video of a kay fuzz tone if you're wondering why union tube got rid of the rocker-based tone control
Thank you kindly!
 
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thewintersoldier

Well-known member
the 100K on the kay fuzz tone is more or less the 33K R17 of the propolis

now let's get specific ... the propolis is bleeding off more signal to ground than the kay fuzz tone and lowering R17 would continue to do that. Placing a trimmer there wouldn't be a very effective volume control as there is always a signal path to the output with 0R resistance

The more traditional route would be a volume control like the fuzz face where the pot is a voltage divider going from bleeding all signal to ground (0R to ground, 500K in series with signal) to passing all signal out (500K to ground, 0R in series with signal) ... in order to do that you'd need to place such a pot on the output and remove R17


and since we're being thorough and you may get curious ... go watch a video of a kay fuzz tone if you're wondering why union tube got rid of the rocker-based tone control
9af71b9c0749cab6d06e80138d3f1a0a.jpg
 

thesmokingman

Paid Hater
If you didn’t remove r17
I just added a 100k pot to the output of the pedal. Like in this build


Works great and at full volume you get a stock bumblebuzz build. On the flip side you can't get a volume boost that way, just attenuation.
not that this fuzz is capable of so much more than unity, if you didn't remove r17 before adding the pot then you actually made it less loud when the volume is full up because you added 100K of parallel resistance to that 33K resistor ... for what? 24-25K effective resistance? from my previous post, lowering the value of that resistor effectively lowers the volume ...
 

Bobbyd67

Well-known member
If you didn’t remove r17

not that this fuzz is capable of so much more than unity, if you didn't remove r17 before adding the pot then you actually made it less loud when the volume is full up because you added 100K of parallel resistance to that 33K resistor ... for what? 24-25K effective resistance? from my previous post, lowering the value of that resistor effectively lowers the volume ...
Well the stock pedal is a lot louder than the unity guitar volume in my experience, that's why I made one with a volume attenuator. Also R17 is 330k not 33k, so I don't know if that make more of a difference in the overall volume drop I would be getting at max volume on my 100k pot. I got 3 builds here so I will remove one r17 from one of them and compare it ^^.
 

thesmokingman

Paid Hater
Well the stock pedal is a lot louder than the unity guitar volume in my experience, that's why I made one with a volume attenuator. Also R17 is 330k not 33k, so I don't know if that make more of a difference in the overall volume drop I would be getting at max volume on my 100k pot. I got 3 builds here so I will remove one r17 from one of them and compare it ^^.
well look at that ... 330K ... probably shouldn't look at the schema on a phone ... the parallel resistance math still holds up ... 76K probably enough to prevent loss but certainly much less than 330K
 
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