Review: Adcom GFA-6000 Multichamp


Category: Amplifiers

First off, my musical tastes, while broad, lean towards jazz, classical, folk, international recordings, and of course, classic rock and roll.
While I enjoy the acoustic tricks that many systems produce, it is all for naught if the intonation and dynamic presence are missing. I am a classically trained musician(piano,guitar) and former keyboardist, so good music and sound, in that order, count heavily. My spouse also shares my background, perhaps with better hearing.
The Adcom supplements the excellent Yamaha. The mains, and center are driven by the Adcom, which is left on continuously. The rears are driven by the two main channels of the Yamaha, and the front effects speakers are then driven by the 4th and 5th channels of the Adcom. As this amp puts out a genuine 100 watts into the first 3 and 60 into the other 2 channels, this works out very well in practice. I should mention that the sound is supplemented by three powered subs, not counting the internal powered subs in the main towers. Still, without good amp control, this system would be unlistenable.
On movies the sound is fast and tight, with the Adcom never running warm, let alone hot. The quality of sound makes me feel that this is one high end bargain. Is the sound as natural as that of a Krell? No, but it will give you a major upgrade from the amp section of any <$ 3500 multichannel receiver. It is almost(almost) impossible to clip, even on demanding music or film. As for the sound characteristic, I would harldly classify it as tube-like, but this amp is really more suited to a system that is not itself inherently bright. Not that the amp is that bright, as a good CD will quickly show, but it leans more towards adjectives like 'fast, controled, authoritative, clean', than 'warm and liquid'. The top can be shrill if really overdriven, but that may well be the PhaseTech PC-500 and PC-33 tweeters, which are directionally adjusted at the listening position, the better to hear dialogue, or the room, which is a less than ideal 20x12x8.. Now, to be fair, on the right recordings it shines even in this heavily HT-biased system( I have another music-only system). Piano sound is especially good, as are jazz ensembles. Vangelis's Opera Sauvage shows off its soundstaging and imaging very well. This is a quick amp, not as fast as the very best, but close enough that you won't likely notice.
But- if you are looking for nonfatiguing enjoyment, careful matching will be necessary. To be fair, the sound of the Yamaha's preamp section has to take a share of the credit/blame. I have not heard the Adcom with a tube front end(know of any multichannel tube pre's?) but I suspect with a tube or passive SS pre, you might easily forget that you are listening to a $ 900 over-achiever.
By contrast, when I have heard the Yamaha by itself, it was OK but not half as well grounded sonically(less controlled, less detailed) as with the Adcom. If you think you need more power than this, guess again. Only extroadinarily inefficient speakers, or a room the size of an airplane hangar needs more juice than this, especially with powered subs. The high damping factor has a lot to do with it, I suspect.
If you are going to use your amp for film/multichannel discs as well as two-channel, this is a budget saver par excellence. It thoroughly separated BoyzIIMen's DTS encoded CD, which is an incredible recording, if somehwhat misengineered as regards tonal balance(too bass heavy on some tracks, unclear on others except on 'Yesterday', which is a religious experience.) I honestly heard both the individual voices as well as the famous harmony, and certainly this was a good challenge for a five channel amp.
P.S. Important note: to be fair, this amp was burned in when I bought it, as I am the second owner. It had just over 7 or 8 months use. I can not therefore discuss the sound of it when brand new.

I would probably upgrade speakers before I would change amps, if that helps put it in perspective. Recommended.

Associated gear
Yamaha DSPA1, Toshiba SD-5100 DVD/CDP,
Phase Tech Speakers, and Tributary Solid Silver cables and connects.

Similar products
Mostly 2-channel amps, the Yamaha listed above is also a multichannel amp, and others by Sony, Krell, Onkyo, B & K, etc. have been auditioned.
prs123
Great review. I own this thing for the past 5 years and have only praise for this Adcom. I got it second hand and use it as HT (DVDs) and music (DVD-A and CDs/tuner) amp.
It's a typical SS amp - powerfull, dynamic and not as musical as tubes. But that makes it perfect for movies and rock.
I don't think I will ever let this one go.
Jank nails it on the head - judge the Adcom on what is was designed for and it comes off as a winner. Thanks for the feedback.