Opinions on Graaf Amps


Does anybody have any expereince with Graaf OTL amps? I'm especially interested in the little GM 20 but don't have a chance to listen to it where I live. Has anybody heard it? In my search for a new amp I have listened to the Carys (572s) and found them overall too bloomy. I don't like tube amps that try to sound like solid state (i.e., Audio Research or BAT) but I also don't want the tubes to color the sound too much. I've tried the Atma-Sphere S 30 which sounded terrific in my system, open, airy and very musical, but it just runs too hot. So now I am considering the Graaf or perhaps an Air Tight. Any thoughts would be appreciated.

My system:

Joule Electra LA 100 MK-III
Merlin VSM + BAM
Audiomeca Keops as transport and Audio Logic 2400 DAC
JPS Super + speaker cables, FX interconnects, and Power Cords

Many thanks,

Dr V
drv
Hi.

I have had a GM2 for 6 years and i can testify to about everything that has been said about it in the earlier posts.
The sound is big, smooth, fast, detailed, controlled. Never heard better, but I have not heard the Joules and Tenors. What I know is that everything else I have heard in comparison sounds slow and syrupy.
But owning the GM20 is not without hassle. You HAVE to buy matched output tubes. That is a must. You have to adjust the BIAS an DC offset about every 2-3 month. For that the amp must be turned up side down, the lid under unscrewed, warmed up, and then adjusted. (So watch out, you may kill yourself if you are really unlucky.)
You also have to replace the large electrolytics resting on top of the amps every other year. They last for about 3-5000 hours. Better replace them in advance in the summertime, before the listning season begins.
And then there is the 8 ohm issue. Take that serious.
And to make it sound the best I can tell you right away: Run it balanced. Do not waste your time using singel ended preamps. It may sound sweet, but you loose the bottom end control.
The best combo I have heard is the GM 20 and the GM13.5B. That is magic.
I also sounds very good if u run it balanced from a Wadia CD player.

But as of January this year, Graaf does not make it any more, so if you want one, you better hunt down a used one. (And then look for the newer types with metal bars on the tube pins. Look inside.) On the older ones, the PCB tends to be destroyed around the tube sockets due to the heat.

I have learned to live with the "trouble". I do most of the service work myself, so I don´t have to ship it away for repairs. Then it works very reliable. I use to say that if you own and drive a Ferrari, you don´t take it to the garage for service with a two year interval. A race car needs service more often to work reliable. But then again, driving a Ferrari is certainly not the same as driving a SUV.

So until I hear something that equals my GM20, that is my dream amp and it rests in my living room.

(Forgive my bad inglish, it is not my native language :-)

Theo

I had a Graff GM 100 that replaced a Symphonic Line RG1.The Graff was replaced by Chapter Audio.Go to Chapter Two power amplifier review:
Eye Fi Magazine, Norway Summer 2002-it is on the Chapter Audio website

The reviewer also repalced his reference GM 100 with the Chapter Audio Chapter Two amp.
To Talk2me:

I just want to point out that the GM100 is a totally different amp than GM20. Both sonically and with regards to speaker compabilty. They both have the musical Graaf "signature", but besides from that they sound very different. The GM20 is also a very good amp though.

Theo
Thanks Freshpuma.I actually had all the Graff amps, one time ot another, in my listening room and they all sounded magical.My point is,as a former tube man, I found a SS amp(in the Chapter) that took my listening experience to another level.
Hi Talk2me.

Well if you liked the Graaf amps, then I have to check out the Chapter amps :-)

BTW: Have you any experience with the GM200. Just wonder how it sounds compared to the GM20?

theo