Originally Posted by zolkis View Post
I have spent about 2 hours with the following gear:
(Energizers)
Stax SRM-007t II
Stax SRM-353X
Nebuchadnezzar: http://knob.planet.ee/amps/staxneb1/staxneb1.htm
(I will call it Nezzar for shorter name).
(Ear speakers)
Stax SR-L500
Stax SR-L700
Stax SR-007 Mk 1 (modified)
Stax SR-007 Mk II
Stax SR-009
Thanks to Audelec (http://www.audelec.fi) for the opportunity. The reason I went there was to hear Erik Konka's Nezzar amp, compared to some Stax amps I know. The Nezzar has recently been reviewed in a Finnish Hi-Fi magazine, and the test unit was still lingering there before going back to Estonia, so I took the opportunity.
Disclaimer: I have no interest, nor conflict of interest and no financial gains in doing this short review.
Since 2 hours is enough just for a first impression, I tried to minimize variables, and used gear that I know. To determine how things scale, I included the L500 and L700 as well. Then, I had well known classical, instrumental and jazz music that I used for testing for many years. Anyway, take all this with much salt: too short time, and too many genres missing. I'd make only a few subjective comments now about the gear above.
The 353X was a positive experience again, it could actually drive all present Stax headphones, and the sound quality was closer to the 007t II than the price difference would suggest.
I would definitely recommend the 353X over the 323S.
The L500 sounded like any other nice headphone, a bit more confined stage than the L700. It's a good (the best) entry level Stax headphone, and good match with the 353X, but I would go and get the L700 instead.
The L700 was closer to the 009 than to the L500, and it is likely the sweet spot of all current Stax headphones. It sounds like a better 507, spacious, relaxed, ethereal, without the 507's problems, and with better sound stage and more solidity in midrange. Of course you get what you pay for, the 009 is more exact, has yet fuller midrange, and better stage, but still, you're not losing much music with the L700. Especially when going from the 353X to the SRM-007t II, or even better, the Nezzar. If you are contemplating the L700, I think the Nezzar would make the best synergy from the amps above. But if you trust Stax more, you'd be happy with the 353X + L700, or with a tube amp and the L700.
The 007t II is like a more harmonically rich 353X, and the Nezzar is somewhat richer and perhaps a bit more refined than the SRM-007t II. The 353X is not much behind these two, though, but the difference is there. The Nezzar makes the 009 sound really sweet and musical, with nicely layered stage and powerful, resolving bass.
I didn't spent much time with the SR-007 Mk II, as IMHO the L700 sounded better, unless you prefer darker sounding headphones with somewhat deeper tonality.
The 007 Mk1 sounded softer than the L700 (in the musical sense, i.e. less hard, though I wouldn't call the L700 hard sounding), with more colors and resolution in the mids and bass. It was more pleasant listening experience anyway. In addition, I like the fact that I can meticulously adjust the headband of the 007 Mk1 to the right fit on my head, something impossible with the new Stax headbands. So no, I would not trade the L700 for my trusty (modified) 007 Mk1.
I don't know if the Nezzar is among the best amps for the notoriously difficult 007 Mk1, but I was happy how it has driven it -- let's call it sufficiently powerful. Again I could not decide if I liked the 009 or the 007 Mk1 more. Each had their strong sides, and no weak sides really.
Anyway the end of the story is that I was quite happy with the Nezzar, reminding me to Leben sound signature: highly musical, resolving, nice layered sound stage, rich in harmonics, yet closer to neutral than to being warm. I'd give it that I liked it more than the SRM-007t II, though for such statement a lot more testing would be needed.
Note that the Nezzar unit I tested looked more like a prototype, but I understood that production versions are on the way. I don't know the exact price, but AFAIK it is quite reasonable. Well done.