Won't preamps become obsolete?

I don't think so. The reason are several fold, of which two are:

1) Separating the first stage from the following stages relieves the problem of frequency dependent feedback through the power supply. This lessens sonic interactions between stages, resulting in better, more lively, sound quality.

2) Hum and noise are reduced without compromising the integrity of the design.

Steve
SAS Audio Labs

Sounds like the preamp, or for that matter the amp or speaker (possibly the extra ICs), doesn't have flat frequency response. (If the preamp is capacitively coupled, the input impedance (Z) of the amp may be too low.)

In otherwards, it is possible that one is compensating, sonically, for the other component(s).

Steve
SAS Audio Labs

Blptwp...What is a TVC? I am guessing that it is a multitap audio transformer. I don't understand your comment about superiority vs a resistor divider. It was a great step forward when interstage transformers went away, and here you are puting a transformer back into the circuit! Transformers have limited frequency response, and if they include core material (like iron) they create distortion. Power amp output transformers have extra windings applied to grids of the output tubes as many dB feedback to correct these transformer deficiencies.

Eldartford,

You are correct in assuming that a TVC is a multitap audio xformer. If done correctly they provide excellent sound today. Xformer technology has come a long way since the days you remember & really excellent sound can be had at a reasonable price. Personally I have heard a very inexpensive passive TVC from Antique Sound Labs (when I was in Atlanta listening to single driver speakers. You did make a post on that thread - it's the last one) & it was quite impressive. Basically, it had no sound! Plus, there was really no loss of high freq. content that I could tell in the 3-4 hrs I listened to that system. I believe that ASL wind their own xformers in-house (China).
Other TVCs made by Stevens & Billington are supposed to be excellent. You can check the freq. response of the same at their website: http://www.stevens-billington.co.uk/page102.htm
I know that it is each to his own but do not under-estimate the sonic performance of a TVC until you have actually heard one! Stellar sonic results are very much possible today. You'll be surprised.
I also know that these days a # of tube amps (both manuf & DIY) use a lot of coupling xformers in them with excellent results. I *think* Art Audio is one such brand & there is a highly regarded DIY personality (Art Loetsch?) who uses coupling xformers in his designs.
IMHO. FWIW.

Bombaywalla...Thanks for the very interesting info. I can understand the advantage of a transformer for a passive preamp, where impedance matching can be a problem. Also, the ability to provide a little gain is nice.

Except for the impedance issue a resistor ladder "if done correctly" should be as good or better. The info shows good frequency response, but nothing about distortion. No idea of price either.