OK, well I'm using a LD2 with HD650s and am very happy with it. Never once have I had even the slightest hiccup with it. However there were 4 versions of the LD2, if the seller will open the 4 bottom screws at the front and back of the case the bottom half of the case lifts away and you will see the version number on the PCB. As far as I know V3 and V4 gave zero trouble. V1 had some issues with capacitors leaking, but I think this was limited to a small number and the units were all fixed. V2 I think were all right, I think they used 1B2 tubes - just can't remember for sure.
If the seller doesn't want to open it up, have a look at the smaller tubes, if they're 1K2 then its most likely you are V3 or V4. Tubes are really only available from the little dot people but are cheap, maybe $20-25 incl shipping for a set. The 1k2 were meant to be a better tube than the 1B2.
As for sounding bright, I couldn't agree with that. I have used mine with the HD650s, HD595s and grado SR60s and none of these cans sounded bright in my setup. The amp however is pretty neutral, so just don't expect a lush "tubey" sound. Frequencies extend well. Prob one of the best sounding amps under $200. It sold for $145 incl shipping, to give you an idea of cost. If you're getting it around the $100 mark and its V3 or V4 I don't think you can go wrong.
Fran
