I know most of the better pre amps don't use a volume pot or know because it effects the sound as stated above. The better way to do this is with a multiposition slide switch and a bunch of resisters. This is what AR does int he sp-16 pre amp. Most now have electronic controls. There is a reason these things cost bucks it is usally not that simple. But all depends on the quality you want.
Can a simple DIY volume knob replace a pre-amp?
If I have only a cd (single source, can I make a simple volume knob instead getting a pre? Since it is simpler and "pure", will the sound better? I know Pre-amp will do some gain on the signal, what is the benefit to have that gain? I am shopping for a pre-amp and come across some people said that a simple volume can replace the pre. Thanks.