If a source has a choice of high (2V) or low (1V) output, then at typical listening levels the pre amp will be attenuating the signal to much less than 1V. Which source output level SHOULD be better?
Always best use all the source has to offer (2v in your case), if it’s not stressed, (which only a bad designer would do)
Then if you find you have too much gain down the line because your volume control is at 8-9am for loud already, then cull the preamp and go unity gain active or passive pre, (if impedance >1:10 ratios are fine, usually are today.)
Quote from Nelson Pass
“We’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.
Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage in a preamp can make it back up again.
Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.
What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.
And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.”