Anyone listen to Zu Audio's Definition Mk3?

Germanboxers,
I understand your point,the Melody 300b SET could just be a mediocre SET amp. There`re so many 300b amplifiers available in the marketplace and at all levels,from sublime performance to poorly implemented.As expected transformer,power supply and parts quality can make or break a SET(or any amp for that matter). Gon member Morganc for example uses my amp with his Zu speaker and seems to love it(there`re certainly other upper quality SET choices), Phil makes a very strong case for high quality 845 based amps. It`s great to have viable choices. That 3-D magic you seek is certainly there with my Takatsuki-300b tubed Frankenstein/Coincident speaker(in abundance). I have no doubt that this is also very possible with your speakers.
Regards,

Germanboxers, your approach is wise. Keep what you have and take small steps. I have close to 15 years in the "high end" of the hobby, and an embarrassing percentage of that time has been spent going either backwards or sideways. And that is despite being rigorously "scientific" and disciplined in doing blinded listening sessions, "research," etc. The only reason I am where I am now (temporarily?) is dumb luck or grace depending on your perspective. What a goofball hobby.

All that aside, I was wondering about what you are "not" hearing currently vis–à–vis your sonic memory of that glorious sound? Is there a single variable that you are able to pin down? Do you think the Atmas are a tad too lean? Your source? Do cables make much of an impact in your system? Speaker positioning have much influence (as Phil suggested)?

For me, I have become more primitive or foundational in my approach. I am fixated on power and the room. I think dropping the noise floor in a system can improve dimensionality but cannot necessarily bring that fleshy palpability. I know for Gary, he was able to achieve those two things through cables and "conditioning" rather than adding another set of tubes. You guys should dialogue as you have owned similar gear and seem to have a similar sonic bias (hiphiphooray@earthlink.net).

Agear, couldn't agree more. My noise floor has really dropped using a standard industrial grade balanced power transformer, I now get that 'after midnight' sound ALL day long. I live/listen in a very dirty power area, surrounded by mobile booster stations/heavy industrial power useage etc.
Additionally the Black Hole bass attenuator has dramatically improved detail threshold in my room.
These two items esp. balanced power have done things NO component upgrade, no matter how expensive, could have acheived otherwise.
Power rules!

>>Agear wrote: <<

All that aside, I was wondering about what you are "not" hearing currently vis–à–vis your sonic memory of that glorious sound? Is there a single variable that you are able to pin down? Do you think the Atmas are a tad too lean? Your source? Do cables make much of an impact in your system? Speaker positioning have much influence (as Phil suggested)?

The Zu/Atma-Sphere combo was a huge step forward in the area of "tone density", dynamic and tonal shadings, and macrodynamics compared to previous systems. That said, and ignoring for the moment the aural 3D processing Phil mentioned, I "think" that what is missing is additional weight/density in the lower midrange (WITHOUT lessening transparency) and additional "air" on the top. Of course, I'm not entirely sure since there are likely other elements that conspired to give that "glorious" illusion in addition to the frequency related ones mentioned above. I'm hopeful that the MkIV's add some of the "air" and I'm considering if the appropriate SET can provide the lower midrange tone density without lessening transparency.

For power I have a dedicated 100 amp subpanel with 4 dedicated lines and run a PS Audio Premier as well. I did the dedicated subpanel with an eye toward possibly placing an isolation transformer between the main panel and the sub, but have not followed through with that option yet. Not entirely sure how to handle grounding...main reason I haven't completed that.

My source is the Metric Halo LIO-8, fed by a Macbook pro and Pure Music software. I've had alot of sources prior, but the three best were: MH LIO-8, Berkely Alpha, Esoteric UX-3 with Statement mod from Steve Huntley of Great Northern sound.

In a head-to-head in my current system, the LIO-8 was far superior to the Berkely Alpha, both fed directly to the Atma Amps. The Berkely was fed by my Windows XP music server via Media Monkey and Lynx AES Digital Soundcard (all .wav files) and the LIO-8 was fed by Macbook Pro via Firewire and itunes/Puremusic (all .aiff files converted from .wav files above).

The Esoteric was outstanding in a prior system, but I had sold it before going the Zu route so no comparison was possible. Incidently, I did extensive testing with the Berkely both in to my Atma-Sphere MP1 MkIII preamp and direct to the amps and found direct to the amps superior. This was the first time in my experience that direct to amps was superior to having a good preamp in between. As a result, I sold my MP1 and freed up some cash...always nice.

The system is not too sensitive to cables, though differences are clearly heard. Just tried some Iso-Clean speaker cables and after a month or so of "playing" decided my Zu Ibis are preferable. The Iso-Clean cables did bass outstandingly, but seemed to lose a smidge of inner detail and top-end air in comparison...not a direction I want to move.

Positioning makes a significant difference in my room, but not as much as some other systems in other rooms that I've had. In a way this makes it harder because differences between great and ok are not as evident so tend to not spend as much time worrying about it (good and bad I suppose, but mostly good from my standpoint...less audio neurosis).

Germanboxers,

Which AS were you using? I used an S-30 with Soul Superflys and disagree strongly on the "tone density" thing.

That was the area to my ears atma was weakest. Transparency, resolution, low bass extension--I'll concede those things.