New H20 Signature S250

Is anyone using these with electrostatic/Soundlab,Martin Logans,etc speakers? I must admit that I am being intriqued by all the buzz about these amps.I presently own a ARC-D150 power and I am on the fence big time.

Regards
Chuckie

I have run my Bel Canto evo4 on a friends Soundlab U2's and was not happy at all. The sound was immediately thin and bright'ish. Just no body and little emotion. Yet on my Magnepan 3.6's, the sound with the evo amplifier was outstanding.

The LC output filter in these digital amps don't sit particularly well with the transformer crossovers (with their associated wide variation in impedance) used in the Soundlab speakers. Also, Soundlabs and other electrostatics have very low inertia diaphrams and best performance, or that which is more critically damped, is ususally obtained with amplifiers featuring lower damping factors (a little output impedance). Just how much this really gives rise to the "thinness" is speculative though. Proper damping seems to have more effect on a systems musicality (or emotion). I think most of the perceived thin sound character is due to the LC output filter and the particular reactive crossover used in Soundlabs.

The Atmasphere OTL series works particularly well with Soundlabs. Other OTL amplifiers will likely also work well since some of their design philosophy is similar. Actually, tube amps in general with their relatively benign resistive plate impedance tend to mate well with Soundlabs.

Greetings all.
Since my last post, I've taken the plunge and had Henry build me an S250 signature. All I can say is, Boy am I glad I stumbled into this chat group. I'd have never found out about this wonderful product without it. Thanks all. Right out of the box, it sounded great to me and seems to be improving with each passing minute. Mine has been paired with both the Sim Audio P-5 and Conrad Johnson PR18 LS preamps, the Von Schweikert VR 4 HSE speakers and a Sim Audio Equinox CDP. Shifting preamps seems to make significant changes in the overall flavor of the system. The PR18LS is apparently voiced more like a tube preamp and has similar characteristics, while the P5 seemed more SS, more dynamic and less colored. This is definately a keeper. In closing, I'd like to mention that a local audio dealer stopped by during my demo. (He's trying to sell me one of the two preamps mentioned above.) I'd mentioned to him that I purchased Henry's amp. He wasn't too familar with any of the new D or T class amplifiers and wanted to hear one first hand. During his visit, he looked it over and comment on its fit and finish. He picked it up and commented that it must have some major transformers to weigh that much. He stood there listening to it for a minute and than said, "What did you pay for that again?" After I told him, he just shook his head and said, amazing. Again, thanks for all your comments and assistence.

Lloydf-

How many hours do you have on your amp now? I ask because in my case (similar dynamic speaker load as yours) the amps seemed to take much longer to break in than those with more demanding loads (such as those driving Apogee's)...

I experienced significant improvement after the first 50-150 hours, and continued improvement well into 500 hours, and the last bit of the vocals becoming fully fleshed out and tube like was close to 800 hours if I recall correctly or so.

Keep us posted on how they evolve with time for you, please. I may be looking into a S250 for a secondary system in a few months... thank you for your input.

Audiofankj,
I've probably got less than 50 hours on my S250, so far. The Von Schweikert's aren't broken in yet either, so I was absolutely floored by how good the combination sounded right out of the box. I suspect that everything will improve with time. I'll keep you informed on my progress. I have one last question for you. I've had the First Sound Presence deluxe at the top of my Preamp wish list, but I'm not truly a tube lover. I much prefer the crystal clear more analytical sound and dynamics of most SS preamps. I've listened to a demo of the FSPD with my speakers, but not with this new applifier. In your opinion, how much would I be giving up going with the FSPD? I've asked you this question before, but in your travels, have you found a particular preamp that would get me closer to where I want to go? The Boulder preamp has the sound I like, but I can't afford it.(Atleast, not with a clear conscience.) I've read a recent 6 moons article on the Brazilian Audiopax Model 5 that sounds interesting, but the chat groups or other reviewers haven't given it much traction yet. I could order it blindly, but I hesitate to do something like that. Your thoughts would be appreciated.