I hear you. Hard to find a one amp for all though, but in your price range Id say the WA6 is your best bet.   Or you could get an OTL like the ming da and pick up something like the asgard in the future, to match the grados.    

Couldn't say as I havent heard it but it sure gets a lot of praise.   The Ming Da would be a good match for your Senns/Beyers, but the WA6 would be a better choice if you intend to get some lower impedance phones down the line

Thanks for the reply, had a feeling that would be the case.   Asgard should be a good match

Go for the M50, bose is fine just overpriced for what you get

Little Dot DAC I   Good value for the money

Well Id say, has enough power for the 598 definately

E7 is a good recommendation, also look at the new E11, I think its cheaper and perfroms above its price point

Really looking forward to these, need a good closed/ high impedance pair of phones

Sennheiser 558 should be good, might even get a pair of 598s in the used section, either one would suit I think

Perhaps the Firestone Little Country III?   Has a relatively small footprint and I dont think its too heavy.

I'm looking into the asgard for my D7000, Jason said its a great match.

Havent heard the WA3, but aside from build quality I wouldnt think it would be much of an upgrade from the MKIV SE? Though the MKIV is solid as it is.   I'd personally save until you can afford something a bit better

I'd recommend the Ming Da MC 84C07. Not too well known but have a search, it seems to be a great match with my DT880 600/ HD 600.   You can get it for 419 shipped I believe on pacific valve

Does anyone have any experience with low impedance dynamics (D5000/ W1000) or is that a bad match for the Lyr?   Thanks