pot lin or log?

[sergio]

How is better pots for tones?
Log or Linear?

I use lin.=treble
log.=mid-bass-and vol.
it's ok?

[Fischerman]

This should be in the discussion area.

Use what the schematics call out. However, I used a log pot for my HRM bass control (all HRM pots are linear in the schematic). Even when using a log pot that HRM tone stack has the typical Bass ON/Bass Off 'jump' somewhere early in the sweep...a linear pot just makes it worse. But that's just what works for me.

[d2camero]

This should be in the discussion area.

Seems like a valid technical discussion to me.


Sergio,

Linear or Log taper is not a question of tone, it is simply a question of what the original amp designer required for the circuit. Log pots are often used for volume levels, because our hearing is not linear (e.g. twice the power of an amp only amounts in a small increase in volume).

does that make sense?

d2

[Fischerman]

d2, it was moved here from the Dumble Files section.

[d2camero]

ahhh, thanks for the explanation. I will remember that next time!

[sergio]

Ok , for the volume use Log. pot , but , in many schematic the type pot for treb. mid. and bass , change.

[d2camero]

Yes, for other place the pot might be linear or log, it all depends on what the designer picked. Often when I am prototyping an amp I will try both types in an area (e.g. variable negative feedback comes to mind). What I focus on is not the tone, but the sweep. I like to make sure that the effect of the control is nicely distributed over the range of movement. That's why there is log and linear.

[d2camero]

It just occurred to me: did you mean what taper to use for tone controls? A typical fender tone stack is Treble log taper, Bass log taper, Mid linear taper. A lot of other designers and builder have used different though.

[sergio]

I think , I'll use Lin pot for TREBLE, REVERB, and log pot for MID , BASS , LEVEL AND DRIVE OD .

[Normster]

Sergio, it depends on which Dumble style you are building. If you are building an earlier style non-HRM circuit, the pots will be:
Vol - 1M log
Treble - 250K lin (log is OK but the amp will "seem" dark)
Mid - 100K lin (or 250K log)
Bass - 500K log (or 250K log)
Drive - 100K lin
Level - 100K lin
Master - 1M log
Presence - 2K lin

HRM wll be:
Vol - 1M log
Treble - 250K lin (as before, log is OK)
Mid - 250K log
Bass - 500K log
Drive - 250K log
Level - 1M log
Master - 1M log
Presence - 2K lin

There are other variations as well, but that's a good place to start.

[sergio]

Thanks Normster , I want start with non-HRM style. thank for help me.