- Joined
- Jul 11, 2009
- Posts
- 2,926
- Likes
- 718
I am glad you think it is working properly and stably now.
No, the ZDS takes a pair of 6C33C-B power tubes that Craig says do not benefit from rolling. The single driver is a 6SL7 tube that does alter the sonic character of the amp. So, there is only one tube to worry about, but unfortunately no overlap with my collection of 339 tubes.
I have had a bad ear infection recently, at the worst possible time it seems, so I have been unable to listen the past several days. The ZDS tends toward a more neutral, fast, and clean sound; however, it still sounds like an OTL amp and has a certain rich and organic signature that can be tuned, like the 339, with tube swaps. This is really hard for me to describe. I was in fact expecting something like the Valhalla 2, a very neutral and solid state tonality, on steroids, but the ZDS was not quite so clinical. It strikes a nice balance between neutrality and the typical warmth one associates with traditional tube amps.
As a generalization, the ZDS is less intimate, more spacious, and more dynamic than the 339; it hits harder in the bass and resolves both macro and micro details more effectively. The 339 is more lush and intimate; it makes singers sound like they are almost licking your ear; there is a real tangibility and immediacy to it. Sounds tend to be softer and rounder, the transients less sharp and incisive. I realize these traits can be changed with tubes, but it goes both ways. I will obviously need more time to confirm these impressions.
The last time I could listen prior to my ear infection, I went back to the HD800, and with this headphone, the ZDS destroyed the 339, no contest. The HD800 can sound hollow and thin, but the ZDS brought them to life in a way I hadn't heard before and made them sound not only technically impressive but highly enjoyable, addicting even. With my modded HD650s, however, I enjoyed the 339 more. What makes this tricky is that I have suspected that my HD650 drivers, which I purchased in 2010, have been damaged since last autumn. Some days they sound normal but others they sound off, just fatiguing and etched in the lower treble and upper mids. Adding dynamat to the outside of the driver has really helped them come alive on the 339, but they sound no better, if not slightly worse on the ZDS. Perhaps it is shining a spotlight on the flaw. The treble especially sounds completely wrong and harsh, whereas the considerably brighter HD800 sounds smooth and effortlessly fluid. If any headphone should be easygoing non-fatiguing, it is the HD650. So I have another lightly used pair on the way, which should give me a better idea hopefully of whether my old ones are defective. It may also provide me with a better basis of comparison between the two amps. After all, Craig apparently tuned the ZD around the venerable HD6xx, even if the updated Super version was also tailored to accomodate the HD800.
What is certain is that when I listen to the 339 after acquiring the ZDS, particularly with my HD650s, I not only do not feel I am missing out but indeed can prefer the 339. My sense is that the 339 remains a very competitive and special OTL gem and that it does things no other amp I have yet heard can do. I have no plans of selling it in favor of the ZD, even if the latter is technically superior and impressive. It is good to enjoy what you have if you already own this fine piece. It is also important to keep in mind the 339 is almost a third of the price of the ZDS.
I will update my comparative impressions as my infection subsides and as time allows. I have not had much time yet with the ZDS to fully grasp its signature, and my position has always been to live with gear for awhile prior to committing to any conclusions.
Thanks for your impressions. I'd considered both these options before settling on the Apex Teton, which I'd love to be able to put against these two one day.