JCM800 Master volume pot question... I used an 800k pot...

[Jeff Hilligan]

your fine on value but not sure if your fine with how it will sound!

 

[Jeff Hilligan]

uh 1meg is not necessarily the perfect value, 500K might sound better it should have no adverse effect. Scraping the carbon might?

 

[MrDan666]

*

 

[duesentrieb]

500k, 1M, even 250k are ok, Dave.

 

[MrDan666]

500k, 1M, even 250k are ok, Dave.

Hey Olaf, would there be any difference tonally?

 

[duesentrieb]

Miller capacitance isn't a big deal in that position after the TS. Peter uses 250k (wired differently), so do I.

 

[duesentrieb]

After the TS the difference is very small, Dave. Its a question of "control" in that place. The lower the value the better the control in the lower volume range.
Thats completely different when we are talking about the gain pot (in a Marshall) though. Here Miller Cap. comes into the calculation. A lower valued pot adds treble and sounds "fresher" - Peter always says that 1M pots (as gain pots) sound "tired", you know
Just try some different values and decide . . . esp playing around with gain pot values is fun.

 

[MrDan666]

After the TS the difference is very small, Dave. Its a question of "control" in that place. The lower the value the better the control in the lower volume range.
Thats completely different when we are talking about the gain pot (in a Marshall) though. Here Miller Cap. comes into the calculation. A lower valued pot adds treble and sounds "fresher" - Peter always says that 1M pots (as gain pots) sound "tired", you know
Just try some different values and decide . . . esp playing around with gain pot values is fun.

Very interesting Olaf, will have to try that!

 

[duesentrieb]

F.i. say you have modded the amp and its so much gain that it gets muddy a bit with the gainpot set to 7 or 8. Install a 250k then - or add a 220k from middle of pot to ground to fresh the sound a bit up. Works wonders . . .