Looking for a great tube headphone amp

Any suggestions? I could go up to $1000.00. Also, any thoughts concerning the Grado RS-1 vs. the Sennheiser HD600 headphones?
The earmax pro should be on your short list. New for around $750 I think. It can drive both Grado's and Sennheisers.

Also, I've seen some used Stax for around $1000, that have a tube amp.

Depends what kind of music and what sound you like as to which is better. I've heard both...
I'm a relative newcomer to the world of serious headphone listening, but I'm using the Antique Sound Labs MG Head OTL with Senn 600s, and it sounds great. You definitely need to upgrade the stock tubes, tho! For $329 new, you really can't go wrong . . . .
I believe that the David Berning MicroZOTL is the best you'll find. $750 factory direct.
The two moderately priced tube models I auditioned for my HD600's were the MF X-Cans v.2 and ASL MG Head DT. In my opinion, the Musical Fidelity beat out the Antique Sound Labs for neutrality and dynamics, as well as bass firmness. It doesn't, however, sound particularly "tubey" (as opposed to the ASL), if that's what you're after. There were some aspects of the EL84-powered, transformer-output ASL that I slightly preferred in terms of spaciousness and liquidity (also jack and pot quality), but in the final analysis, it was just too colored and slow compared to the 6922-powered, output-transformerless MF (which was used alone - not with the X-PSU upgrade AC transformer). I'm a tube fan, but this ASL sounded excessively old-fashioned to me, while the MF was natural, articulate, and extended (and featured better casework). The MF adds a pair of loop outputs for signal pass-through as well, making it easier to integrate into systems where line-outs are at a premium for recorders, processors, etc. Guess which one I bought? As for the 'phones, I tried the Grado RS-2's, but found them bass-heavy, lacking a bit in clarity, and uncomfortable (just plain heavy) compared to the HD600's - whose prodigious resolution admittedly does come at the expense of a little thinness.
I would also look at EarMax and Wheatfield Audio. Both units are tubed and in your price range. I am currently using the Wheatfield Audio headphone amp and have been quite pleased with it.
I have an MG Head DT that I'm pretty happy with. Sound improved alot with EI tubes. I have a pair of Sennheiser HD 600's. They are very accurate sounding, but somehow a little unexciting. I have a pair of Grado SR 325's that are a little more dynamic and exciting, but are more prone to ear burn and sometimes sound a little congested. I enjoy my Stax 303 classic set the most, though the sound may be dark to some ears. They are probably inaccurate compared to the Sennheisers. More fun to listen to though, and being primarily a speaker guy, I like them because they sound more like speakers. You might want to look into trying out a set of recent model stax lambda series (sr 303 or 404)headphones with a tube amp (SRM T1, SRM T1s, SRM 006t etc.) Older stax headphones tend to be a bit more unforgiving and hard sounding.
I would check out the Berning MicroZOTL and the EarMax (maybe the Wheatfield too...I haven't heard as much about that one).

You really need to listen to the Grado's and Sennheiser HD600 and make your own decision. They're both great headphones and both very different.That needs to be your decision, based on your own prefernce.
I've owned an MF X-CanV2, Wheatfield HA-1, and ASL MG Head OTL. My preference and current amp is the MG Head. I like a tubey laid back amp with headphones so I use the transformer output rather than the OTL. All three are very good headphone amps. The Wheatfield can also serve as a single input preamp (which is how I got into the whole tube-based system). As described by the folks at the HeadRoom, the Wheatfield is less tubey and more dynamic. That same description has been used when talking about the Berning microZOTL (which can be used as a 1w amp). For a little over 300, the MG Head is hard to beat though. -- You can find interesting discussions of these and other headphone amps at www.head-fi.org. Good luck.
Don't rule out the MELOS SHA-1...
I'll cast my vote for the ASL MG Head amp driving the Sennheiser HD600. I don't find it excessively tubey, very good bass, excellent dynamics and revealing without being brittle, an excellent combination!
I second the Melos SHA1 or its relatives. Sounds very, very good and reasonable from a tube rolling standpoint. You get a pretty nice pre-amp in the bargain, too. I am a dedicated Stax man, but appreciate the Melos, also.
Interesting to see that I'm the only one here who didn't find the ASL MG Head DT to work to his satisfaction with the HD600's, hearing a consistent sonic signature across all of my sources that comparision revealed was endemic to the amp. For the record, since some of the above folks mentioned this, I did invest in a new pair of JJ EL-84's and burned them in well, but didn't find the sound a whole lot improved. I returned the unit for a refund, but I currently have no use for the upgraded tubes, which have a long life ahead of them...offers, anyone?
Before you buy a tube headphone amp consider the GRACE 901.This is the amp used by the best engineers extant and what they final master what you wind up listening to yourself.At 1300 retail, not cheap but when I am listening to my HD 600'S sourced through the audio aero mk1 with the GRACE I feel graced.
With the Antique Sound Labs, it's important to get the newer OTL version of the MG Head. While I haven't heard the DT, I assume that it sounds similar to the OTL model in "transformer mode," and I find its performance in OTL mode to be much better than with the transformers in the signal path, either with or without feedback.

Also, the tubes are critical -- the stock tubes are NOT good, and do the amp no justice at all. I pitched the stock tubes, went to eBay, and picked up a pair of NOS Sylvania black-plate EL84s and a barely used Telefunken 12AX7 for about $75, and the Head sounds like a different (and much better!) amp.
You might also want to check out the forums at headfi.org. There is a lot of good feedback on them.

I have been 'Head FI-ing' for a couple of years now.
I currently own ASL MG HEAD w/Electro Harmonic Russian TUBES.I use both Senn. HD 600's w/ Cardas cable upgrade & Grado 225's.The best thing is this Amp is wired for both.
Both phones have there characteristics, thats why I own
I just sold my MF X-Can V2.It was great, but not much in the way of looks.Hard to tweak too!No complaints on the sound.But the ASL is a cool looking Amp w/ great sound!!!
I like that fat tubey sound anyways. The EL84's have a sound
that the 6922's don't.But it's all in your Ear & Head anyway.Everybody's different, thats why you have to addition
the choices and hear the differences yourself.
Gilbaino, it sounds as if we basically agree on what we heard, and just have different preferences. In another thread a while back, someone posted that the current-production MG Head DT now eschews the use of an output transformer, like the X-Cans (but I can't see any differences on ASL's website). If this is true, it might well be that factor, and not the tube type, that was responsible for the ASL's more rounded sound - anyone with knowlege of this alleged development? As for the X-Cans themselves, I have to add that I've been very disappointed with the quality of their unusual, sealed output jack design - I've gone through two of them so far, and still can't get a reliable connection with any of my 'phones.
TUBE TECH of Denmark makes an excellent unit.
Tube Tech proffessional audio gear is the very best od its kind, no question. Its imported by, TC Electronic here in the states and carried by pro audio dealers mostly.
A pro audio complex by the name, Wind Over The Earth, in Boulder, Colorado had such a demo unit recently.
303 443 9822 is there number.

Mike Schneider