Gamut audio

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I got to know the GamuT amplifiers when a local Hi-End magazine made an evaluation of the M250 monoblock and an interview with the CEO - who also designs the amps.

GamuT started building amps and monitors for recording studios. The amps are very well regarded. The topology employs a single power L-MOSFET per rail at the output stage. From the pictures it seems to be the BUZ900X4S/BUZ905X4S from Magnatec.

Later on I listened to one of them on a Hi-End show in town. They sound wonderful.
 
They are one of the very best amps for sure.

Uses jfet input, voltage stage (I think) and "complementary" single pair output mosfets.

Relatively high bias, I would guess some 10W class A in the GamuT D200. Think it idles at 130W or so.
The stereo D200 uses one big trafo and four big Rifa ´lytes. Small bypass caps over the big ones.

Few parts but not really "Passish" in design as far as I
understand.

/Peter
 
Got an image from the guts of the M250. The transformer is 1.6KVA and the 'lytes are 47.000 uF Vifas.
 

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D200 impressions

Hi,

I have tested the D200 some years ago, before the hifi rescue came over me by Mr. Nelson Pass offering his aleph schematics for DIY freaks...

It, at least the D200 – but the other Gamuts will be similar - can do some parts of the magic Alephs can offer. But IMHO my Aleph4 monos are so much better in sound. The D200 is fast, open, homogeneous. But there are this distortions maybe all not single ended amps have, the soul of the music suffers, it becomes clean, cool and a “technical” sound. But for sure the D200 is excellent – but what is the enemy of a good thing? Aleph is IMHO the better for not dampening requiring speaker monsters.

Maybe one of the reasons for the clear well focused sound of the D200 is the used P2P flying wiring of the PSU. I made again and again the same experiences, specially with speaker crossover networks: any peace of PCB track for power currents destroys a lot of sound. A simple 1,5 or 2,5mm² wire is the best connection where current must flow – no flat and thin track (influencing the current with its current- and frequency depending skin effects affecting the effective impedance).

Klaus
 
Klaus

"no flat and thin track (influencing the current with its current- and frequency depending skin effects affecting the effective impedance)."

It´s the other way around, a round wire affects the current with the skin-function, more than a flat conductor of same gauge.

I can´t see how you can describe the GamuT as cold and clinical, it´s far from as warm and colored as the Aleph´s though.
I think most people can agree on that even though the Aleph amps are very good and musical, they are relatively colored, especially in the higher range.

The GamuT does not have the "typical" SS distortion, it has a similar distoriton pattern as the Aleph amps, therfore a similarity in sound, only that GamuT is cleaner and more dynamic IMO.

Distortion numbers in the GamuT is among the lowest in highend amps, about one 1/10 of the Aleph if I remember correct. Also the distortion is 2nd order dominant with falling level towards higher frequencys, as it should be. One other similarity to the Aleph is the rise in distortion from 1kHz, which manifests itself in a ever so slightly "foggying" of the last two octaves or so. My bipolar class A, no-feedback Zapsolutes betters both Aleph5 and D200 in the higher registers and the deep bass.

/Peter
 
Peter

I just described what I have heared... No claim of being totally right.

I also know the theoretical side of the skin effekt - but there seem to be other effects.

Last week a guy with the ZAP solute wrote me after having finished his Aleph 2 that the solute has no chance. Everything is totally subjective...

What do you think and how have you explored Gamut amps?

Klaus
 
Klaus

"I just described what I have heared... No claim of being totally right."

Ok, do you mean heard for yourself or told by others/read about it?


"I also know the theoretical side of the skin effekt - but there seem to be other effects."

Yes, other effects than skin probably does this. I would guess stored electric and mechanical energy in the PCB´s. Maybe interference between stages/traces as well.


"Last week a guy with the ZAP solute wrote me after having finished his Aleph 2 that the solute has no chance. Everything is totally subjective..."

Of course it´s subjective to a big degree, and also it´s important to have low coloration on every part of the reproduction chain, (including the room) in order to "judge" components correct.

I compared my Zapsolutes to a homebuilt Aleph two a couple of years ago, and both were very good in that set up, the Zap a littel cleaner/clearer. Biggest difference in the mids and highs. Speakers were Totem Mani2 and a two way Accuton/Thiel&Partner. In that set up I could have lived with both but prefered my Zap.

I also had the Aleph5 at home for some time, and really liked the warm sedducive midrange (spokey with some vocal material), but it lacked dynamic to the Zap, and didnt have the extension and resolution in the highs as the Zap have. IMO Aleph5 is a wonderful amp, very musical but far from neutral/uncolored.

I had the GamuT at home for a week or so, and REALLY liked it.
However, it lost some points to the Zaps. Didnt reach down as low in the bass, and didnt have the same control as the Zap. Also it reminded some about the Aleph but was somewhere between the Zap and Aleph in tonality. The Gamut didnt have the resolution in the high registers as the Zap´s have and did not have the same enormous soundstage (precision).

GamuT being a 200W and Zap 78W, the GamuT was the winner when playing at high levels, and especially at rock/pop.

I also compared the D200 to ARC VT100mk2 in a set up, there was nothing the VT100 did better than D200 and I mean nothing.

The best amps I have heard to date is;
LC Audio Zapsolute
GammuT D200
Aleph.

All have their strength which can suit some set ups and ears but non of the mentioned amps have made me change the Zaps, even though I am "actively searching for something better".

BTW what Zaps did the person have that wrote to you?

I have the 78W dual monos = 500VA + 30VA trafos 260.000uF in each block.

IMO the Zaps have extremly high resolution, and if there is problems earlier in the chain, chances are a warmer sounding amp can be experienced as better. But without excessive jitter, with good cables and discrete class A analog stages from DAC to the input of the amps, chances are the sound is very close to the best possible if neutrality and resolution is the goal = magic IMO.

/Peter
 
Peter2

Hi Peter,

thanks for your comments again. Very interesting.

Yes, I also tested the D200 home. My Aleph 4 monos are build with excellent divice quality and all tweaking tricks. Maybe that is the reason that the D200 fall so far back.

The friend who said his Aleph is better than Zap also tweaked from the beginning on his monos, so maybe that is the reason that his Aleph is better regarded IN HIS SUBJRCTIVE VIEW. It covers my experiance - some good parts and the same amp is toatally different. Sometimes much better.

Klaus
 
Ex-Moderator
Joined 2002
ben goh said:
Hi,

Has anybody any infor on Gamut audio amplifier ?

The website has not much details to provide,

It has one gain stage similar to the Passlabs amp.

Any relation with Pass ?
Hi Ben,

I took some photos of the Gamut D200 at the CES. You can see them here.
http://dlison.dyndns.org:10004/RoddYama/index.php?pageType=folder&currDir=.&startFrom=11

There are some specs in the captions.

It may not be the best sounding amp in the world, but it sure is one of the biggest.

Rodd Yamashita
 
I used the BUZ900/905 L-mosfet pairs in a class-B amp I built some years ago. In my case, I used three pairs per channel, and the amp will push 300W into 4 ohms. They seem to handle the task with ease, and the amp sounds fantastic, especially considering that it's a class-B design (based heavily on Douglas Self's series of articles in EW&WW magazine). Distortion is extremely low, just as you'd expect from a Self design. I'm keen to see how it stacks up to the Aleph-X, which I should be finished building in the near future. As far as the FETs go, I don't know if I'd feel comfortable pushing 200W with a single pair, especially with high bias or class-A. But, check the datasheets. However, their higher-rated "D" and "X4S" versions look like they'll do the job. In fact, the X4S devices look really good.
 
"can a single mosfet pump up 200 watts or higher ?"

Yes, obviously since the GamT D200 is a single pair/channel and 400W/4 ohm amp :)

Then there is the M250 amp which is also a single Mosfet pair/channel (as far as I know), it delivers 250W/8 ohm and 500W/4 ohm.

The S600 monblocks uses a balanced dual pair of single pair mosfets (4 mosfets/channel "bridged") and delivers 600W/1200W/2400W in 8/4/2 ohm!

/Peter
 
Comparison between D200 and M250

Hello,
I actually own a D200 and I have the possiblity to get a pair of M250 for a fair price.
Do you think that it's worth the upgrade ?
The power supply of the M250 seems to be a lot stronger.
Other question : on the picture of the inside posted here, it seems that there is nothing connected to one of the heatsink : is it true ?
Thanks for your help,
 
Re: Peter2

Klaus said:
Hi Peter,

thanks for your comments again. Very interesting.

Yes, I also tested the D200 home. My Aleph 4 monos are build with excellent divice quality and all tweaking tricks. Maybe that is the reason that the D200 fall so far back.

The friend who said his Aleph is better than Zap also tweaked from the beginning on his monos, so maybe that is the reason that his Aleph is better regarded IN HIS SUBJRCTIVE VIEW. It covers my experiance - some good parts and the same amp is toatally different. Sometimes much better.

Klaus

Sorry if this is little off the thread reply, but i couldn't contact you trough email.

Could you provide some links for tweaking aleph 4? I know that D200 and if aleph 4 can be made sound better, i want one...

really much... :hot:
 
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