Cgs synth

> Hi...
>
> "The preamplifier of the stomp box adapter [has] an AC gain of 20",
> and in order to have a gain of 10, I was thinking about a swtich >

--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
>
> >Then I wondered : why do not swap the switch and resistors by to
> >potentiometers, one for amplifying, the other (passive circuit)to
> >lower gain...?
>
> Why not?
>
> >AMP : 470 for x20, 1k for x10 and 2k2 for x5, 4k7 for x2.5...?
> >ATT : 1k for x20, 2k2 for x10 and 4k7 for x5, 10k for x2.5...?
> >
> >So 4K7 and 10K linear pots would be okay for a x2.5/x20 gain
> >excursion ?
> >(Linear ? even with audio signals processed ?)
>
> I usually use linear for everything. Log would not work when
replacing the
> smaller resistor. You would need reverse-log.
>
> >I guess the 470R resistor should be keep in place (maximum gain
value
> >x20) as the 1K attenuating resistor, to keep a certain gain-
> >relationship between the two potentiometers at position 0...
>
> Yes, otherwise you risk driving it to distortion.
>
> You could of course replace the other resistor (across the op-amp)
with a
> pot. With that resistor reduced to zero, there would be no output.
>
> Ken
>
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> Ken Stone sasami@h... or sasami@c...
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