[sdiy] Tapped volume pot: extra tone control?

[Roy J. Tellason]

On Monday 12 November 2007 21:36, anthony wrote:
> On the original radio for the amp I am making, there is a center-tapped
> pot. with a 0.02uF connected in series with a 47kOhm resistor to ground.

I'll bet that tap is a bit off-center.  :-)

> Does this have the effect of rolling off the high-end a bit as you turn the
> volume up or vice-versa? Seems a bit weird since the radio has a separate
> tone control anyway. I guess it's neither here nor there since I need the
> cap (it looks like a halfway decent film cap) and am not going to be using
> this circuit in the final amp.

That provides what they called a "loudness contour",  basically giving you 
some treble cut (and therefore boosted bass) at lower volume levels.  Same 
sort of thing as that "loudness" button you'd see on some stereo gear.

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