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.
Kalan- those are all good points- did not realize the Gamut was 'adjustable' in that way... Hey- a fellow Coincident owner huh? The SEIII's are cool, and in fact more flexible in that I have found a wider variety of amps that can sound good through them. I recently had the Victory's updated to 'II' status at Izzy's place (he lives 15 minutes from me here in Toronto, which is handy!)- increased resolution, yet not in any harsh way, in fact the greater inner detail was immediately apparent.
Jtgofish- sounds like we are on the same wavelength with SS amps- agreed on the chips- they could be the way of the future, however equally likely seems these 'digital switching power supply' amps like the Bel Cantos I tried. In fact, if you can believe this, when I plugged the BC's into the BPT line conditioner, all of a sudden my Accuphase fm tuner went all staticky- sp?? also- my television (also plugged into the same line conditioner) had snowy lines through the picture on certain stations!! Those digital nasties from the amps are definitely not for me- maybe they would work for someone in an all-digital, audio only system with very careful electrical isolation...
>>Hazy is how the vast majority of SS amps sound<<
IMO that is an unfair and general mischaracterization of solid state amplifiers. Perhaps your other components did not match well with the amps you've heard. Thank you.
It is a generalisation and I accept that a lot of people don't seem to hear this and maybe never will.We do not all hear or at least listen the same way,but there are also many people who hear this haze and prefer valve amps.Not that some of them don't also sound hazy,but the good ones certainly don't. You owe it to yourself to hear the chip amps.Use one for a while and then switch back to your transistor amp.You will probably get a real shock regarding midrange congestion [imaging,dynamics,clarity,speed] just as I did.Over the years I have owned and tried all sorts of SS amps[even single ended class A].I can't say that I did not enjoy listening to some of them but everything is relative,and these devices really are becoming dinosouars[good for driving bass though],and probably would have become so a long time ago but for the conservatism of amp designers.[or unwillingness to embrace alternatives]
There are just as many people who feel chip or digital amps don't sound natural, and neither does their clarity. Many, including myself, would take issue with your statement that SS amps are dinosaurs on their way out. This haze thing is getting blown way out or proportion in this thread. Every tube amp I've owned had glaze and haze. The only ones I've heard that have the least of this are the VTL Wotans at $40K.
Kevziek, there is a heirarchy that exists in chip amps just as there is in tube and solid state. There are chip amps I would not own, nor care to listen to for very long. The best have a clarity that cannot be matched by Mosfet amps, due to the science that governs the switching technology.
My chip amps, connected to my system, are more real than any tube, or solid state amp in any system I have heard. I am a fan of live music, mostly classical. I have a musician daughter who has kept me going to the auditoriums regardless of the venue.
I think Mosfets do have a place in the future powering preamps, and low wattage amps, like Nelson Pass's, "First Watt," amp. My own preamp is solid state. Give a Mosfet and a chip amp a big load to push, and the chip amp will come out on top.
I might be totally wet on this but check out Nelson Pass' First Watt series of amps-especially the new J-FET one. It has about 1/5 the distortion of MOSFETS and even though it is of low wattage, your speakers should present a decent pairing. He only makes a hundred or so and then its DIY time. He does it all himself so there is a waiting period.
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?
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.
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, 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.
agreed on the bi-polar aspect (and I am not descibing my personality, although my wife may disagree :-). They do have more raw power- case in point- my previous HT system consisted of a few pairs of rather inefficient Totem Mani-2 speakers that sounded great once 'pushed'- the amps I used on them (Sim Audio; Theta Dreadnaught) used bi-polars - they had more 'grunt' if you will, but the speakers needed it.
Nonoise:
thought about the First Watt, however the room is huge and I like to rock out sometimes- I think the FW might lack some balls- I could be wrong- just a feeling from experiencing the Pass Aleph 30 in the same system previously- a nice analog 'warmth', but not the greatest dynamically, and the noise floor too high for me...
However, I find greater 'purity' (I use the term somewhat loosely with solid state,- my Custom 45 2-watt tube amp over in 'system b' would disagree:-) with the best of the 'chip' amps- caveat- given a reasonbly efficient speaker. Perhaps so few parts translates to putting one closer to the music? It's an interesting discussion that would probably make a good thread- overall SS amp toplogies- their pros and cons. Again, speaker & room synergy is the key IMO...
Kalan:
not surprised- Izzy is a good guy, but he is real busy- he tends not to do auditions unless there is a good chance of a sale in it...
Mural:
what chip amps are you speaking of/using? I wonder how their topology would differ from the Audiosector Pateks...
I use the H2O Signature monos loaded with B&O's newly improved 500A modules. These modules require an add on power supply. There use to be an argument about which class D module sounded the truest. I believe B&O has put that argument to bed.
The chip amps I am refering to are the Gainclone type.They use Panasonic chips.I have two of these-a paralelled 4780 which is 100watts RMS and will drive difficult loads and a 3876T Sonic Art which is 56 watts RMS.They both sound very similar to me but the 3876T is probably a bit warmer and open in the midrange.
I actually used the 47 Labs Gaincard S (higher output version with double power supplies) for about two weeks with the original Coincident Super Eclipses a few years ago. The 47 Labs US rep (can't remember his name) said that even though he believed the Supers were not as benign of a load as advertised that they Gaincard would still be appropriate for those speakers.
I tried the Gaincard S with a pre-amp (Cary SLP-98P at the time) and direct. It sounded much better without a pre', but my normal SLP-98/SLAM-100 combo sounded better in every conceivable way. No aspect of the Gaincard's performance was remotely competitive with the Cary separates. Now, my system was configured for the tubed separates, and I did not have 47 Labs cabling on hand; so the synergy could have been all off.
The minimalist chip amp thing may have come a long way since the Gaincard and with the right speakers it may be the bees knees, but I would have to revisit the whole thing with easy-drive speakers, flexible and light cabling, etc. to find out.
Kalan, Yes my chip amps do sound best with efficient speakers but are also very good on hybrid stas that are quite a difficult load. On balance I still prefer a good valve amp but these things ,to my ears, still leave the vast majority of transistor and digital types for dead.The fact that you can put a kit one together for around $300 makes them really special.If nothing else they are excellent back up amps to SETS or big PP valve amps and great for using when the temperature is just too hot to put up with hot running valves.
Thanks Sutts, interesting comparison to the First Watt as that also looks like a good design concept.
Muralman1, from what I understand the definition of "chip amp" they are NOT digital as in switching power supply. They are analog amps where virtually the whole amp is on a single chip. Big difference in measured performance as chip amps don't have the HF hash of Bel-Cantos, Charlize, T-amps, etc.
Cdc, people are reading, "Chip," as the tiny plate on a circuit board, where actually in the case of the class D modules I have seen, there is a circuit board loaded with minute circuits, and equally miniature resistors and caps, thus they are a module, not a chip.
The modules are analog. What's digital is their power supply. ICE provides a module sans power supply. It is this module, the 500A, that enables a brilliant amp builder, like Henry Ho of H2O, to expand the performance beyond what the digital power supply modules can attain.
I was very pleased with B&O when they spent countless hours improving their 500A. This is a low sell module, as few builders want to trouble themselves perfecting their own power supply. B&O doesn't need to do that. They just want a feather in their felt hat.
Jtgofish: Yes, the hot-running valve gear does become a problem in warm weather. I have always felt, until just recently, that running valves was worth the hassles (tube replacement costs, heat, can't leave them on 24/7, etc) because the sonic goods the gear delivers are so rewarding.
But...after 20 years of using tubed separates, I am going to try the GamuT M200 monos (breaking in now). So far, they show great promise in creating a similar kind of large, open, transparent sound stage that the Cary SLAM-100's do. They are also musically engaging and seem to have a more even-handed tonal balance and handle the highs and very lows with the same even-handedness as their mid-range. The Carys seem to have a more transparent mid range, but the Carys' extreme highs and very lows are not as fleshed out as their mids, upper bass, and lower treble regions.
I may miss the eerie valve midrange realism, but the over all presentation of the Gamut M200's from top to bottom is damned good and pretty addictive. The Gamut trick of valve-like physicality (palpability?) and sound stage depth is the best I have experienced from SS in my system. (Plinius SA102 MkII, Goldmund M28, BAT VK500, and 47 L Gaincard S, among others)
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.
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.
Kalan- please let us know how the Gamut monos work out for you- curious, how was the Plinius SA-102? Did you have it with the same speakers?? Plinius definitely seems to have their fans as well... btw- I had heard somewhere that the lower-powered (25 watt??) 47 labs amp (Gaincard??) was actually the better soundign one than the 50-watt version...
Cdc & Mural- thanks for expanding the desciption of 'chip'- good info...
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....
Sutts, you also asked about the Plinus SA102 MkII amp. Yes, I used the same speakers I have now: Super Eclipse MkIII's. I liked the amp; among the other SS amps I was trying out (Goldmund SRM 150's, and Goldmund Mimesis 28M in quick succession) the Plinus seemed more alive, more coherent, more liquid, and maybe just mated with the First Sound pre-amp better compared to the Goldmund amps. I liked the Plinius amp, but not enough to buy one.
Now, I have heard the (significant) step up Goldmond 29M in another system that just worked wonderfully with the Placette Audio Active Linestage and Talon Firebirds. The 1.45 V input sensitivity of the 28M just may not be enough to let the First Sound drive the amp properly, or something.
To me, the Plinius SA102 MKII seemed to be a more complete amp, in my system.
Kalan- thanks for the updates. How are the Gamut M200 monos on the ambient heat factor scale? are they warm to the touch; do they hear up the room? Incidentally, what is the size of your listening room?
Sutts, Both the D200 and the M200's run cool, with the M200s running cooler still than the D200. The M200s are just barely warmer than the room itself. The two-only MOSFETs per channel are mounted on the side of the chassis, equal distant apart and in the middle of the flush side of two, large heat sink banks.
The M200s space their transformers fairly far away from the main board and other signal-carrying wiring and have two, much bigger power capacitors per channel than the D200 has.
My room is a small-ish 12.5' x 17', with low-pile carpet & pad over concrete and lots of open cell acoustic panels--placed mainly at the first and second side reflection areas and behind my listening position. The speakers fire down the long walls and are positioned well forward into the room (from the wall behind them).
May I ask why you ask about the heat and room size?
Hi, I am Michael Edinger, of MusikLab.dk Musiklab.dk I made (designed) the latest 3 upgrade of the well received D200 amplifiers from GamuT , as well as all their other analog stuff- like S300, M250, D150, D3, etc. until 2005. The D200 k mk2 and earlier were a bit less transparent in the midrange and treble, and the GamuT mk3 (2003 was last version for GamuT)upgrade adressed this with a complete redesign of the circuit board. The "Haze" mentioned occurs with sensitive speakers and ears- when listening to a cold started Mk2 or Mk3 for the first 1/2 hour or so. Reason: the GamuT amps warm up very slowly (>30 min´s) due to high thermal mass and a slow bias circuit setting and regulation. To avoid Bias overshoot and meltdown it is set below the optimum value for sound. In my self produced MusikLab D220 mkIV single MosFet power amplifiers this issue is adressed with a sophisticated redesign of the Bias circuit that allows a faster warmup( < 5min´s), and maintains an optimal Bias setting and thermal regulation by monitoring the output device crystal temperatures immediately. The Musiklab products are available via the musiklab website above.
Sutts (and others reporting 'haze'), how is your power? I modified a power strip with a small (< 1 uF) high-voltage (400V) film capacitor across the hot and neutral lines, and noticed immediately a reduction in 'grain' and 'haze' from my Hafler amplifier, which uses MOSFETs. My approach is very similar to the original Shunyata Hydra-4 power conditioner, which only uses a single 0.1 uF isolation capacitor across the hot and neutral of both duplex outlets in the unit. (Note: DO NOT try to build one of these if you don't have electrical training. AC power KILLS.) This very rudimentary power line conditioner made a startling difference in my system.
It's possible that what is being described as 'haze' is the result of dirty power.
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