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SS amp mosfet 'haze' - ever experienced this?

Tried a new amp in my system on the weekend: the well-reviewed Gamut D200 mkIII (partly based on HP's great review), a single-mosfet SS design. At the dealers' place, it sounded great (speakers were Wilson Benesch Discovery, an isobarak, lower-efficiency design). I can't use a tube amp right now (unfortunately!) due to pending child and the system is on a LOT (2-ch/HT mix), so am looking for the most full-bodied SS amp I can find (prefer fully balanced design to match my modded SF Line 3 pre).

Well, to my surprise, the amp did NOT work out as well at my place. My speakers are 97db Coincident Total Victory. Yes, it was full-bodied, but I was definitely aware of this haze, or veiling around each note. I have a friend who designs amplifiers, and he said that this is inherent of mosfet designs. I called Israel (Coincident) and he was not surprised that I only heard this once I got back to my place, due to the high resolution abilities of my speaker vs the speakers at the dealer's. I guess I will be sticking with my Sim Audio W-3, as it is much 'cleaner' on my system (given that I must stay with SS). Too bad, 'cause my Sim W-3 definitely has the edge in clarity, but the Gamut was a touch more full-bodied.

Has anyone else experienced this 'haze' with a mosfet-based design? I admit, those with higher-efficiency speakers like mine (97db/14ohm) probably are NOT using higher-powered mosfet designs anyways, but I would like to know how others feel about mosfet designs and this issue I had.
sutts
kalan
185 posts
 
Tvad, I also lived with the DI-150 GamuT integrated for about four weeks. While it is good, as you mentioned, the First Sound pre-amp feeding the GamuT M200 monos as a combo comes much closer to the holographic presentation of tubes. While it may not quite have that last bit of 3D-ness of a good all tube system, the First Sound/GamuT combo actually has a better proportioned sound stage. Tube power amps sometimes tend to bulge the front center of the stage a bit forward in relationship to the outer edges and the rest of the imaginary "stage."

I am not a sound-stage/image freak, but I have noticed the more correct relative proportionality of the GamuT amps sound staging over some tubed power amps. As fantastic as that "see into" holography of some tube amps can be, the GamuT seems to get the over all completeness of the staging pretty well nailed.
jtgofish's avatar
jtgofish
209 posts
 
Kalan,
If you want fleshed out treble you should hear a Supratek Grange or Cabernet preamp with TJ meshplate 300Bs.Nothing I have heard comes even close.This is what I have been using with my $300 chip amp.An absurd mix of budgets and technology I know but it really works.
tvad
9,467 posts
 
Tube power amps sometimes tend to bulge the front center of the stage a bit forward in relationship to the outer edges and the rest of the imaginary "stage."
I agree. It's a quality I tend to like, regardless of it's inaccuracy.
cdc
1,412 posts
 
Thanks Murlaman1.
kalan
185 posts
 
Sutts, I have also heard that among Gaincard fans, the 25-watt version was usually favored over the 50-watt S version. Since the S version could not come close to powering the Coincident Super Eclipse I's (at the time) properly, I figured the standard version---for all it's alleged better qualities---just wouldn't have the gusto to work well with the Super E's.

I can report on the GamuT M200 monos, though. They are breaking in nicely. All the elements over the already good D200 I had hoped for are present in the M200 monos: more solidity (palpability[?]) to their presentation, larger (particularly deeper) and better defined sound staging and just as musically engaging as the D200.

They M200's also sound considerably more powerful and controlled than the D200 stereo version with deeper, more commanding bass. The D200 is gone; so, I can't make a current, direct comparison. But I spent a month with the D200 and started using the M200's directly after the D200. No regrets.

If I had a bunch more money, I would consider two D200 amps in vertical bi-amp configuration. The extra cost (over M200's) and the additional cabling would kill me right now.

The M200's are working well with about 300 hours on them. I have heard they continue to improve beyond that. We'll see....
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