I check online ads for old stuff.  I chuckle at what some people covet.  Latest thing was I was looking for pre-amplifiers.  I have one and I like it and it was a good one for its time.  I just saw another slightly newer from another company which is probably better. I am thinking about getting it.

I know what a complementary symmetry circuit is.  I know what FETs are. I know how tube circuits work, mostly. 

While investigating my options today I saw a number of really expensive tube preamps.  They were Dynaco PAS-3s.  Some were modified some were restored all were pretty expensive.  They are NOT worth it.  Back when they were discontinued I was around and getting into audio.  That model was replaced by two subsequent Dynacos one with transistors and the other with Gasp..., Op Amps.  Those were considered far superior to the obsolete Pas-3 by the main stream mags.

Back then there were two preamplifiers that were the ultimates.  One was a Harman Kardon Citation 11 transistor unit and the other was the Audio Research SP3a1 a vacuum tube machine. The favorite by a nose was the tuber. The PAS-3 was considered inferior to both by a wide margin.

Crazy that I saw a Citation 11 for half the price of a PAS 3.  I know which one is better.  It aint the tuber.

Eventually praise for those machines became complaint as the shine wore off. The SP3 is considered non-linear and inaccurate now.  That is because it always was but the flaws sounded nice like sugar in your coffee.

Some people think that the AR machine was a cost-no-object tweak of the Pas-3.  Massive regulated power supply and selected premium components and a slightly different circuit. Reality is more complex, but they all used common principles. Interesting that in the mega-buck wars it was superseded by many other devices many of them using transistors.  For a while AR tried to sell transistors, but the customers did not want them.  They are still in business and still make tube equipment.

I have a big problems with Tube electronics.  One is that they physically wear out and are expensive to maintain.  Another is a feature where you can buy different brands of tubes and get different sounds.  Nut jobs will actually have alternate sets of vacuum tubes to adjust the sound of their system to complement the music they listen too. If you want accuracy that should not be possible.  If you want sweet syrups in your music then fine.  I drink coffee black.

The unit I am thinking of is a transistor beast, from the 80s. I found the circuit diagram.  It is really cool and interesting in that they used a really different and more complex circuit in it.  I suspect it sounds better.  It has complementary symmetry and a couple of FETs.  It has a good reputation.