I wouldn't want all them tone controls in the line of my signals... There are ways around pre amps,
Put a TC-716 with a Control Freak and for around $80 you can have a few sources and switch it how ever you like.. I have a couple tc-716's they are awesome... It adds and takes away nothing from the source material, and I recently got a control freak and that also is silent, I have to say that simple volume control knob is awesome, its silent, and so well made it seems to be a waste, lol...
As most of you know I believe in the least amount of switches, filters, ect in the signal path, so I looked inside the TC716 and you can not get much simpler than that, and its well made. It has no set input or output locations. So you can plug your inputs into any of the rca spots and your output into any, as long as you depress you outputs number the amp will get the signal from what ever other output number you select...
Whats nice about this is 1-its super direct, 2 its inexpensive, and 3 you can choose multiple inputs at once or multiple outputs... So if you have a cd player on one and a microphone on another you can sing along or play Karaoke what ever you are into, you can do super fast A/B comparisons if you want to compare a set of speakers and have 2 matching amps or if you want to compare cd vs mp3 vs vinyl with the same song, ect its endless....
So like I said no need for a preamp, use the Control Freak with a switching box and IMO it will perform better and do more than a preamp, WITH NO POWER circuits....
http://www.amazon.com/TC-716-Stereo-Selector-BLACK-VERSION/dp/B0001F347K/ref=sr_1_22?ie=UTF8&qid=1407937480&sr=8-22&keywords=rca+selector
https://emotiva.com/products/electronics/control-freak
want to plug in a pc add a dac
http://www.amazon.com/Signstek-Coaxial-Converter-Decoder-Analogue/dp/B00FEDHHKE/ref=sr_1_2?ie=UTF8&qid=1407938744&sr=8-2&keywords=muse+dac
want to add a turntable add this guy
Amazon.com: Behringer PP400 Ultra-Compact Phono Preamp: Musical Instruments TCC also makes one that matches the switcher
Amazon.com: TCC TC-750 BLACK Audiophile Phono Preamp, Pre-amp (Preamplifier): Electronics
you can have a pretty versatile system for under $150, for another $60 add a headphone amp and you can have your speakers going as well as a set of headphones both with separate volume controls
http://www.amazon.com/Bravo-Audio-V2-Multi-Hybrid-Headphone/dp/B00ADR2DTG/ref=sr_1_4?ie=UTF8&qid=1407939823&sr=8-4&keywords=headphone+amp ... Also you don't need to spend $50 on the emotiva control, but its a nice unit, Pac and a few other companies make them for around $15...
http://www.amazon.com/PAC-LC-1-Remote-Amplifier-Controller/dp/B0002J226O/ref=sr_1_1?ie=UTF8&qid=1407938976&sr=8-1&keywords=volume+control+rca
If you are really motivated you can get one of them project boxes and install it all inside there, my brother did this a while back but he bought all the parts and soldered it all up, a very simple preamp system, I think he spent around $80 total with 10 inputs.. Manual switched only power was used for phono preamp wich had a power switch to shut off all the power when it wasnt being used..