Audio Note, Audio Logic, Kora Hermes Dacs ?

As an Audio Logic owner, I can tell you its strengths are all of the items you list, particularly with respect to natural dynamics and dimensionality. There is an "aliveness" to the unit that makes most other DACs I've heard sound sterile and lifeless in comparison. It is not a "tubey" sounding or euphonic unit by any means, although you can play with the 12AU7 tubes in it to change its sound a bit. That ability to "flavor" the sound is probably changing now, as Jerry Ozment is removing the 12AU7 tubes and replacing them with transformers (at least that's his upgrade he's doing on the units, I assume he's likely to be doing this on all future production of the 2400). I'm having that upgrade done now and, if you're interested, I can let you know the results in a while; Jerry is very high on the upgrade, feeling it makes the unit sound more real to him.

Can't comment on the other two units, although from all reports here I honestly don't think you can go wrong with any of these, just a matter of which one best meets your sonic priorities.

Pat, that's pretty much correct--he's keeping the 6DJ8s in the circuit, but the 12AU7s are the tubes that most affect the sound of the unit. I have other tubes throughout the system which I can use to tailor the sound to my liking, so I still have plenty of flexibility there. I thought a good deal about this point, and Jerry acknowledged it when we talked about it, but a few things made me decide to try the upgrade:

1. Jerry will change it back for me if I don't like it, and the cost of the upgrade is at the point that I can afford to take the loss if I really don't like it;

2. I've owned the Audio Logic DAC since 1994, first in its prototype form, then got a later version of the Model 34, and finally upgraded it to 2400 status. In each case after the first I spoke at length with Jerry about the changes involved and the improvements were as described by Jerry, and were quite significant without affecting the best things about the unit. I think a lot of Mr. Ozment's designing skills and his ear and musical sensibilities, and am willing to trust his judgment about this upgrade, about which he's really quite excited; and

3. My experience over the past year with the Lamm LP2 phono stage, which uses a transformer for MC stepup rather than tubes (as my JP200 does), has led me to be extremely impressed with the way a transformer, properly implemented, can be used to increase the gain of a low-level signal without losing any of the virtues of the tube sound I like so much. And it is much quieter, very important with the small signals involved. I had been hoping that the Jadis phono stage would prove vastly superior to the Lamm, as selling the Lamm would free up some shelf space and help pay for my kitchen renovation, but to my ears it is not--while each has its strengths, in my system combining the Lamm's accuracy, better layering and depth and quietness with the Jadis' naturalness, dynamics and huge soundstage from the line stage is the more satisfying combination for my tastes. I'm coming more and more around to the view that it doesn't hurt to get your sources as quiet and accurate as you can (without sacrificing musical virtues), then using your preamp and amps to tailor the sound to most convey the soul of the music to you.

Now watch, I'll probably like it better the way it was!! At least there are used units around which can be picked up for a comparative song which will have the tubes, if you want that flexibility, and who knows, maybe Jerry will offer the choice to purchasers. Anyway, I will be glad to let you know what I think, FWIW (it'll be a while, as I have to get it back and my house is in disarray with this construction going on); I'm fortunate in that I have the AL analog stage, with tubes, on my Sony SACD player, so I can run a digital out from the Sony and do a pretty good A/B test.