What headphone amp to buy-Sennheiser HD 600?


Well, thanks to the kindness and patience of my fellow A'gon-izers, the hook-up "problem" for the headphone amp I have is solved. The amp is a Ramsey SHA 1. The phones are Sennheiser HD 600. I had remembered that amp sounding great. Now I'm spoiled by the new speakers I have, and even though the signal path to the amp is thru the Dodson DAC, I still think it sounds........not so great. Decent I suppose, but harsh on the upper end, yet without the mitigating detail, and you know, just.....unsatisfactory.

OK, OK, so here's the question(s): What's a great, fairly cheap (like, at LEAST less than a grand) headphone amp? Sonically, I want EVERYTHING!!!! (Except soundstage, that has never happened for me with any headphones, ever, I'm pretty sure not even with the expensive Stax I heard a few years ago).
It MUST have: Tight, deep, fast, smooth, tonally correct, musical bass, shimmering, non-fatiguing, emminently smooth yet ultra detailed highs, great midbass punch with no boom or softness whatsoever, midrange that is totally natural, smooth, detailed, and lacking any hint whatsoever of grain or electronic amplification artifact in the upper registers. It should sound great on ALL program material, from classical to rock to bluegrass to new age to jazz, anything and everything.

Other than those relatively modest criteria, there are no other performance demands. :)))

So, fire away!
mdhoover
Marco,
I DID it! I took your advice and bought some tubes from the seller you steered me toward. They're on the way, and pretty soon it'll be time to get things "rolling".
-Bill
Great Bill. Post your results once you get them. I'm sure it may be helpful to others with the Stax amp you have. I'll be curious to hear how they stack up to. Did the seller have any input on the subject? Have fun rolling!

Marco
Marco,
Thanks for the quick reply. Yes, the seller did have recommendations, and in fact he put together a package of tubes for me. I'll let you and the others know when I know something.
-Bill
To anyone and everyone who knows about tubes (including Swampwalker and Marco):

Swampwalker has mentioned "tube biasing" with the Stax 006t. Is that amp a later generation of the SRM T1? That's what I have. Will the tubes have to be "biased"? If so, what's that? How does one bias tubes?
-Bill

Footnote, somewhat tangential and "optional" reading: I recently figured out that the headphones are the Lambda Pro Signature version, not the Lamda Pro. I don't know for sure whether that's "better" or not, but I think it is. Being the brilliant audiophile that I am, I managed to accidentally damage the one of the headphones' diaphragms with the vacuum cleaner, while trying to clean out the crumb from the degenerated foam, so the headset's out at Yamasinc for repair. Based partly on what Swampwalker said and partly what I read in a review, I opted to repair these back to Lambda Pro Signature status (with the thicker diaphragm) instead of trashing them and getting a new pair of 404's, which have a thinner diaphragm. The BEST idea would have been not to damage them in the first place. Oh well.....