I have had the 5800 for 2 years and have had no problems.It has performed very well with my system.
I recently upgraded my system by changing to the Sony DVP-S7000 as my audio CD player. It has made a signficant difference in the how my system performs. Bass freq is apparent; smooth midrange and highs yet the highs are very distinct. So-called soundstage seems to be much larger than with the previous CD player.

My previous CD player, Sony CDP-35 ( inexpensive CD player ) my system was not performing near its potential.

The reason I mention the change in source was to indicate that the 5800 was not the limiting factor in the presentation of the music and that when reviews of equipment are presented the person needs to understand the limitations of their system and not simply conclude that it is one component that is the cause.

Another example was when I first put the 5800 into my previous system ( Scott S-10 speakers, Sony CDP-35, Kenwood preamp ), the change in character of my system was very apparent; it sounded much better. Again better bass rendition, smoother sound, and larger soundstage.

My system :

Aerial 10T
Krell KRC3
Adcom 5800
Sony DVP-S7000

I use homemade interconnects which consist of 3 silver plated copper wires that are interwoven with a tightly woven shield.

As a last comment; I have known no product is sold will always perform faultlessly. The nature of manufacturing a product.

Class A to 20 watts,Good pace, excellent dynamics, sweet sound from the MOSFET's, Great Bass Handling

Weak in detail and some grain in the treble and HF

I purchased 2 of the amps to biamp and biwire my speakers. They preformed very good and presented a very believable sound stage with excellent dynamics and reasonable inter detail. Previous to the Adcoms the Bryston 8ST drove the speakers biwired (8ST is four channels of 200 watts). The Bryston had excellent bass and delivered a balance sound but it lack in dynamic to the Adcom 5800 pair. (8ST amp became the center channel and surround channel amp in home theater) In January 2001 I purchased a used Mark Levinson 333 to drive the speakers. In February 2001 one of the 5800 Adcoms was sent to Musical Concepts in St. Charles MO. for $400 John turn the amp into a close match for a Conrad Johnson or Audio Reserach solid state amp. The trebel and HF became grainless, the inter-detail was much greater and the sound stage grew by 50%. If you want an excellent amp by a used Adcom 5800 and send it to Musical Concepts. YOU WILL NOT BE DISAPPOINTED. The amp after John's mod's rates 5 Stars. The modified amp in is a second system in my den.

Similar Products Used:

Adcom 555MKII, Bryston 8ST, Mark Levinson 333, Conrad Johnson MF85

I purchased a 5800 2 years ago. I had nothing but trouble with the clippingl.e.d. on the left channel lighting up all the time; bright at start-up, and
then barely visible the rest of the time. Recently, the 5800 "died" on me,
so I sent it to Adcom, N.J. for repair. Turned out the problem was simply
a fuse. After getting it back, the problem recurred, at which point, my
dealer offered to exchange the 5800 for the new 5802. The 5802 sounds ab-
solutely tremendous, with smooth mids, tight bass, and sparkling highs. The
only problem is that the new 5802 always produces a low cycle hum, which is
an apparent characteristic of ALL 5802s, not just mine. Driving a pair of
Acarian Systems Alon IVs, I'll probably look to Krell or Pass Labs to fulfill my amplification needs and expectations.

After listening to the 5800 for 2 years I still have mixed feelings about it . First I am on my third amp. First amp sounded anemic (no bass). Second amp sounded ok but blew-up after 3weeks (smoke&fireworks).My present 5800 is doing fairly well .It sounds as good or better than Sunfire,Carver,NAD,Rotel at a comparable price. It seems to be hard on my NHT 3.3s 2 departed lower mids 3 fried crossovers . In my 20+ years of audio experience I have never seen (personally) this kind of failure rate. I guess mabye I expect to much but then theres my NAD system 15 yrs still kicking. In short ,the 5800 sounds detailed,uncolored,good tight bass. ( if its working properly ) At $1600 list it seems a great deal for its sound&power but for me the cost is reliability which is where I do not compromise well.

ADCOM GFA-5800 AMPLIFIER

I've owned the adcom 5800 now for about 2 years. To me the sound is superb !I'm presently using legacy loudspeakers. The sound is terrific. I've used other how powered amps but nothing compares to the Adcom.

I had the opportunity to audition a used 5800 some time ago. I was looking forward to hearing it in person after learning about its design (a classic Nelson Pass design, the only significant difference between the Adcom 5800 and the much more expensive Aleph amplifiers is that the 5800 adds a push-pull output stage to keep the amp from blowing up. Admittedly, this is a fairly significant difference). The amp weighs a ton--another sure sign of quality. Between its pedigree and obvious build quality, I was prepared to be blown away. Needless to say, I was disappointed. I found the Adcom to impart a cold, steely quality to the sound--very clinical. The sound was detailed to the extreme, but proved fatiguing in the long run. Listening to Sarah McLachlan's Solace and Surfacing (two of my favorite CD's, along with everything else Sarah has ever done) was not as intoxicating as I had remembered. The Adcom got the timbre right, but was devoid of any feeling or soul. I also could not get past the annoying mechanical fans. One thing the Adcom did do very well was take control of a speaker's bass. I had never heard such deep, tight, and tuneful bass from Paradigm Espirits before. I could not stop playing Dr. Dre's The Chronic--one of hip-hop's all-time great albums. The bass was phat, nasty, stinky, and tighter than a blow-up doll. The Adcom's bass is superior to almost anything short of a Bryston or Krell. I even found it superior in the bass to my new reference amplifier, the Sunfire. Overall, I preferred my old Carver M-500t for its superior smoothness. Subsequently, I auditioned a Sunfire, and the Sunfire has now found a permanent place in my system for its far superior (to my ears) midrange. The Sunfire, when used with the Current Outputs, has the most liquid midrange I have ever heard from a solid state amplifier--the closest thing to tubes without tubes. I'm not saying the Adcom 5800 is a bad amplifier--far from it. In fact, it would likely prove a great match for dark-sounding speakers with a warm-to-fat midbass. I would try the Adcom with Vandersteens or Mirages. Also, if you listen to lots of hip-hop, funk, disco, or blues, you may find that the Adcom is your ticket. If your tastes run toward chamber music, classical, acoustic, folk, or female voice, you may not like the Adcom. The 5800 has been replaced by the 5802--I have had the chance to hear it at the local audio salon, and it seems to have improved upon the 5800 in exactly the areas in which I find it lacking. Overall, the Adcom 5800's sound just did not do anything for me. Associated equipment: VAC tubed Vintage Line Amplifier, Carver MV5 CD player with Musical Fidelity X-10D tubed buffer stage, Paradigm Espirit bipolar speakers, Audioquest Quartz x3 interconnects, Audioquest Type 4 speaker cable (double bi-wire), Panamax 1000+ line conditioner, and Radio Shack RF stoppers placed on all the power cords.

I recently opened this baby up --guess what I found-- some of the cheapest wire I've ever seen(the type used by computer sound cards to connect to a CD-ROM, but cheaper), there is about a 1 foot run from the rca inputs to the circuit board-- it basically negates the effect of any type of good interconnects you use. So I stripped it all out & rewired it with some warm spacious sounding tara-labs quantumIV. It made a very noticable difference in the highs-- stripped away the last bit of stridency & made the amp over all sound much fuller and round, the sound stage also improved-- If you have one of these amps it could make you want to hang on to it for a little longer.... It it a 4 star amp at list, but since I paid $800 for it it's a 5

Lots of initially impressive power. But after serious listening I realized that the bass had a ballooning quality to it. Maybe some people call this "fat" bass. Whatever it's called I don't like it. It's all power with no finesse. In addition I feel that the high end is recessed, cold, and a touch steely.Then there are the goddamn fans. The right side is constantly on and is as loud as my computer-maybe louder.I called long distance to the states and the Adcom service department basically blew me off. They said that as long as the amp wasn't shutting itself down there was no problem. Bullshit! If the customer is not satisfied, then there is a problem. The left fan has never kicked on even after playing at abusive sound levels. That doesn't seem right.
These problems didn't become apparent until after I'd moved overseas and it was too late to cram it up somebody's ass.I am currently just tolerating its presence by using it as the bass amp in bi-amped system. IMHO this is all this amp is good for.

There is no reason to buy this amp. The Bryston 3BST, At the same price is a MUCH better souding amplifier.