impedence value.? amp to preamp.

Hi Atamasphere,

There are some preamp designs that put volume pots at the output. What do you think of them?

I just bought a preamp that uses 100K volume control at the output. It works well with my power amp which has a 500K input impedance. However, it sounds thin with another power amp that has 60K input impedance.

Please comment. Thanks.

Hi Bob, no worries! The higher the value of the control, the greater its artifact (and that of the cable) is going to be. If you have a higher input impedance, like Vett93 above, the problem you get into is high frequency roll-off.

The lower the input impedance of the amplifier, the harder it will be to get bass at low volumes.

Essentially you can regard a passive system as a sort of tone control that also affects the volume. Because TVCs have greater control of their output impedance they can offer greater performance in this regard if other factors are also taken care of.