Ideal Volume level

Sugarbrie is correct. Your preamplifier's natural state would be to have the volume control all the way up. Any setting lower than that is attenuating the output from where it wants to be.

The position of the volume control is also meaningless. Where you end up is a function of the relationship between the source/signal you are listening to and the preamp's gain combined with amplifier and speaker sensitivity. Volume position can be radically different for each source. For example: if you have a low output MC phono cartridge (as I do) you may find that on some records you can "peg" your preamp's volume without getting as loud as you would like. And that is perfectly fine.

With older preamps that use a potentiometer for volume control, the higher up the pot, the better the sound because the pot is an impediment in the signal path and at higher settings you are listening to less of the pot. Many modern preamps (like the ARC SP16 mentioned) no longer have a pot in the signal path, but instead use a reistor network or ladder that provides nearly identical performance at any volume setting.

Thanks Davemitchell, I finally understand the mystery of volume control settings and why there use to be a "sweet spot".

Wow; didn't expect so many great answers.

I really don't listen very loud, normally. Probably 90-95 db would be the norm (peaks at these levels).

Thanks!!!!

A resistor ladder does nothing different than a potentiometer. It just does it more precisely (assuming high quality components and design.)

Think of it this way. A pot or ladder simply dumps part of the signal overboard. The earlier description of a preamp with no volume control being at full blast is correct.

Volume attenuation devices can also be placed at different spots in the gain stages of a preamp circuit. They do not automatically result in an increase in noise floor or a decrease in dynamic range.

I did not say they result in increased noise floor. EVery component has a baseline noise floor. I was describing how the smallest voltage details rise from the thermal noise floor as the voltage division (as the wiper moves or the ladder is varying) result increases. In 99% of preamps on the market the line level signal from the source fisrt meets the passive volume control (potentiometer, TVC, ladder what have you) and then it hits the constant/fixed gain stage (6 dB, 12 dB, 18 dB whatever)

There IS NO GETTING AROUND thermal Johnson noise (that is)physically inherent in every resistor device in the known universe.

There is a sweet spot and it does have everything to do with optimizing the dynamic range and your overall system "sensitivity"

Dave Mitchell: The ARC devices use a digital potentiometer (a plastic case 5 volt IC) that depending on the digital (bit level) value switch in series internal resistors...it is identical in fundamental operation to stepped attenuators. Except in the IC the signal ALSO flows though active devices (multiplexors and buffers). Pick your poison.