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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
jtgofish's avatar
jtgofish
515 posts
 
Muralman,
I am interested to hear about the way chip amps switch compared to transistors and why this could be a clue as to their sound.
Are there any web articles about this?
cdc
1,845 posts
 
Agree about chip amps being great but don't think they have the drive of bi-polar solid state. They just can't pass that much current.
Digital and chip amps are not the same thing. Look at measurements and digital switching amps (Class T or whatever) and you will invariably see a lot of HF hash or filtering to try to get rid of it. A well designed chip amps has neither.
kalan
185 posts
 
What are chip amps? Could some one please explain/clarify.
kalan
185 posts
 
Sutts, Yes the Super E III's do tend to mate with a lot of different amps. You are lucky to live so close to "Izzy's" there in Toronto. I visited Toronto two or three years ago and phoned Israel Blume to get a tour of the Coincident factory. No go. He said that there were no Totals, Supers, or Victorys in house to hear, etc.
muralman1
1,527 posts
 
Kalan, Chip amps is just another misnomer, like digital amp. The proper nomenclature is Class D, another analog type. There are chips on the circuit boards. The circuitry board with all it's resistors, capacitors, and chips is called a module.

I don't mind the nick-name, "Chip amp."
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