Won't preamps become obsolete?

Most volume controls in amps and CDP are of low quality volume control which really restrict dynamics and sound quality. If you are thinking going direct from source to amp, you need a very high quality volume control. I listen to vinyl only and I have a phono stage with a pair of transformer volume control (TVC) which is arguably the best kind of volume control. Some audiophiles use TVC in a passive box for their CDP. Most CDPs have digital volume control, which is the worst thing you can have. In any preamp, whether it's active or passive, volume control is extremely critcal, it could act as the bottle-neck for the whole system. TVC is expensive, but is really worth the money considering it control the sound level of your system, which could be many times the money of your volume control.

Further to my comments regarding volume control and transformer volume control (TVC). I like to add that I have the same TVC as in the Bent Audio passive box, but as built-in in my tubed phono stage, custom made by Kevin Carter of K&K Audio. I don't have a linestage. In my phono stage, I have a set of output for vinyl and another set for CD. The output for CDP goes directly to the TVC, so it's like a passive linestage without gain. Eventhough I don't listen to CD, I have this CD output just in case I get a CDP later. I have tried a CDP in this set up, it has more than enough gain. Most CDP have output of 2 volts. For my phono stage, it has 65dB gain, my cartridge is the Koetsu Rosewood Signiture with 0.6 dB and I have more than enough gain. Let me tell you, the dynamics is unbelievable with TVC. Standard volume control is resistor based, which suppresses high frequencies, bass and dynamics, TVC dosen't do that at all. I have numerous phono stages in the last 20 years and this is the best of them all.