Last Breadboard of 2022: The Timbre Man

[Fizz]

I recommend tantalum for C11...

Newb question: Just curious what the difference would be and why you recommend tantalum?

 

[Chuck D. Bones]

Lower leakage, lower noise.
The difference between aluminum & tantalum will most likely not be audible in this case.

 

[HamishR]

I forget where I read it - maybe it was here! - but apparently the reason Paul C made the VREF voltage splitters asymmetrical was to help guys using batteries which were running low on voltage.

 

[temol]

I forget where I read it - maybe it was here! - but apparently the reason Paul C made the VREF voltage splitters asymmetrical was to help guys using batteries which were running low on voltage.

My explanation of the asymmetrical Vref is: it allows to maximize headrom if there's an asymmetrical clipping in the circuit.

 

[Chuck D. Bones]

I forget where I read it - maybe it was here! - but apparently the reason Paul C made the VREF voltage splitters asymmetrical was to help guys using batteries which were running low on voltage.

Smells more like rumor than fact to me. Cochrane is not the only one to offset Vref. Look at the series of BE-OD / Dirty Shirley pedals.

 

[HamishR]

Well I won't be repeating that nonsense again!

 

[MattG]

@Chuck D. Bones, what is the purpose of R9? In the most recent schematic it's 470k parallel with the C500k treble pot and R7/7k5, and in the earlier schematic, it's 100k parallel with the C100k treble pot and R7/1k5.

Isn't the net effect of R9 to essentially half the treble pot value? IOW, in the newer schematic, could you drop R9 and use a C250k pot (or in the older schematic, drop R9 and use a C50k)?

 

[Chuck D. Bones]

@Chuck D. Bones, what is the purpose of R9? In the most recent schematic it's 470k parallel with the C500k treble pot and R7/7k5, and in the earlier schematic, it's 100k parallel with the C100k treble pot and R7/1k5.

It's purpose is to smooth out the sweep at the bottom end of rotation, from 0 to 3.

...in the newer schematic, could you drop R9 and use a C250k pot (or in the older schematic, drop R9 and use a C50k)?

Yes, you can do that if you want to, but the sweep won't be as smooth at the bottom end.