Transformer coupled outputs/inputs in preamplifiers.


I have been a big fan of VAC preamplifiers, both for their musicality and their ability to optimally mate with all solid state and tube amplifiers I’ve owned. I believe this is strongly related to use of transformer coupling at output and input. Are there many any other tube preamplifier companies that use transformer coupled outputs (+/- input transformers). I am aware of the SE preamplifiers recently from BAT with transformer coupled outputs and a recent offering from Prima Luna, I believe. Any thoughts on these preamplifiers or others. Yes, I am aware that transformer coupling has its strengths and weaknesses, but I am convinced (after 15 years using VAC preamplifiers) that output transformers are generally the answer for compatibility issues. Thanks so much for all your kind input.
audiobrian
+1 to the OP, I'm kind of a fan!! :)

I like expensive caps, but there's something quite different about transformer coupled inputs/outputs.

I don't know how many realize that if you listen to a vintage recording, you are probably listening to the end result of quite a few of them.
My custom-made linestage has input transformers and output transformers.  In my case, the output transformers are kind of necessary because my amp has complementary input transformers and does not play well with all linestages.

Why limit yourself there?  Choke loaded preamps, preamps without capacitors in the signal path. etc. DHT deisgns, etc.

 
I didn't even think about this being a factor in why my VAC preamp pairs so well with my Pass amp.  I had attributed much of the synergy to the impedance match primarily but this makes a lot of sense.
Before my 15 year ‘love affair’ with VAC preamplifiers, I did try many well respected preamplifiers including  Halcro, GamuT, BAT, CJ, Audio Research, and Mark Levinson. All of these fine preamplifiers required some matching, sounding excellent with some amplifiers and less than optimal with others. Using amplifiers including GamuT, Clayton Audio, Audio Research, Luxman, Pass Labs and VAC, my VAC preamplifiers were never less than fully compatible. Although it may relate to VAC quality and voicing, IMHO the VAC output transformers seem to contribute much to their supreme compatibility.  This is just my opinion from many years of experience, not circuit or electrical expertise. Thanks to all.