Interesting... and an excellent and very detailed review.
A everyone here probably knows by now I'm not a fan of how tube gear editorializes on the sound of an audio signal.
(To me, you either play something accurately, or you change it - regardless of whether some folks find your change an improvement or not.)
I would also have to say that I consider a $3k stereo analog preamp to not exactly be an economy model...
However, all that said, it looks like Audio-GD has delivered an excellent example of what a tube preamp should be...
Construction quality looks to be very good...
They've used film caps, which is especially important at the voltages used in tube preamps, and should ensure a long service life...
And they've also paid proper attention to smaller details, like orienting transformers at 90 degrees relative to their nearest neighbors...
I agree at being somewhat surprised that they didn't use DC to light the tube filaments...
But, when done properly, and with tubes that aren't especially sensitive to it, this is not at all an issue (and the performance will tell there)...
Some modern tube products sound "too tubey" - to the point where they just sound unpleasant...
But a tube preamp that fails to impart at least some pleasant tube character to the sound is really just wasted effort...
(If you want a preamp that actually sounds totally neutral then it's much easier to do that with solid state.)
And, from the review, it sounds like they've "struck a good balance" between tube sound and lack thereof...
One comment I would make is this...
With tube power amps, you should expect tubes, and especially the driver and main output tubes, to have a limited service life...
However, with a tube preamp, you should expect tubes to last a very long time...
So, with a tube preamp, a good long service life for the tubes signifies good design...
(And a requirement that the tubes be changed very frequently definitely signifies the opposite.)
And, again, Audio-GD seems to have done their job properly here.
This would also seem to be an excellent choice for folks who want to consider combining a tube preamp with a good solid state amp.
Presumably it would impart just enough "tube sound" to be noticeable - without doing so to excess.
(They also seem to have hit all the other highlights I would look for - like a remote control and balanced outputs.)
