Good and tight base, warmth, revealing details, biwire output, balanced input

Fan, power switch

I bought this amp (5800) when it first came out about 5 or 6 years ago. So far, I had no mechanical or electrical problems with it. I thought this amp sounds very good, at least with my KEF Ref3 speakers. I am satisfied with the amp although I wish I had the later model - 5802.

I initially used the Adcom GFP 555II preamp with the 5800 amp but later changed to the Melos SHA gold preamp. The sound quality is improved significantly. The warmth and sonic details from this amp were finally revealed. I think I will keep this amp for a while.

I submitted a review of this amplifier earlier and wanted to update it since I have spent even more time with it and have since upgraded other components in my system. The Adcom 5800 continues to amaze me now more than ever! It is so incredibly natural,spacious, dynamic, and balanced in its sonic reproduction! It is slightly different sounding than the Pass Aleph 5, but every bit as good in quality of sound. It ties with best amplifier I have heard at any price (Aleph 5) and is quite a steal at its retail of $1600. MUCH better than the Acurus A250 and Mark Levinson 331, and somewhat better than the McCormack DNA-1.

The best amplifier I have ever heard! Much more dynamic and spacious than its competition and comparable with the best at any price!

Liquid mids and highs, power reserve is NEVER an issue. Only overt character is a slightly euphonic coloration (not really a bad thing in my book, that's why I have a tube preamp after all)

Yes there is that mechanical hum from the power transformer, fans do run but I can't hear them at any thing close to realistic playback levels. Does run hot, but does not as far as I can see impact reliability or stability. (It is biased nicely into Class A operation and that requires a lot of electricity and thus makes a lot of heat)BUT THAT CLASS A OPERATION SURE MAKES IT SOUND GOOD!!!

I got an excellent deal on this after selling my 5500, only paid 50 bucks more than what I sold the 5500 for. I origionaly just wanted to be able run a balanced system from my pre to the power amp. I was expecting just a little more Ooompf than the 5500 but what I ended up getting was the most glorious sound that I have had the pleasure to hear eminating from my speakers. Hands down the best amp I've heard under $2500. When I first used my 5500 after listening to my 555MK II for 2 years it was a revelation. Beautiful liquid midrange and top end, much less harshness, and best of all the amp didn't loose the magic at higher listening levels like other adcom products I've used. (people who like adcoms bipolar transistor amps over their mosfet amps are either deaf above 1500HZ or really like to have their ears bleed. I've had both and know what means) There was no compression of the sound stage and MOST IMPORTANTLY, no listening fatigue,something I often experienced with the 555 and 535.
Which brings me to the 5800. The differance between this amp and the 5500 was not as great as the differance between the 5500 and the 555 in terms of the tonal differance BUT, and this is big, the 5800 had all that the 5500 did and so much more in terms of soundstaging and depth of sound field. Abosolutly fabulous from deep bass to the top treble. I would say it has that smooth tube sound (mostly second and third harmonic distorion, same as a SE tube amp) without having rolled off highs and bloated tubby bass. I can honestly say that anyone who rates this amp below 4 stars either hasn't listened to it or has a grudge to settle with ADCOM. I also want to address the two weak points of this amp. I feel they are worth putting up with because the sound quality is just so great. The Buzz from the power transformer is audible during pauses but doesn't bother me while the music is actually playing. The fan whirr is also audible, but again I can't hear it when the music is playing above the level of a normal conversation.+

Similar Products Used:

Adcom GFA 5500, GFA 535, GFA 555 MKII

I really always felt that if your going to choose to purchase an amp in excess of $1500 dollars, you would be hard pressed to find one that was just "not good." I'm aware that certain amps work better with certain speakers, but after I borrowed the 5800 from a local dealer for a week I was hooked. It's power was effortless and when I matched it with a low impedence loudspeaker (Thiel CS7), there was no strain at all. The Thiels I borrowed was just to see what the amp could do (I tad bit to high for my budget). It has tremendous low end, and an extraordinary ability to deliver highs as smooth as I heard when compared to PS Audio, Parasound amps. It works great with the Definitive Technology BP2000's and would recommend it for those people who feel their speakers are a little on the bright side.

Power, accuracy, detail, brings the best out of live CDs

low Fan noise (i measured 30 dB 8 ft away)

I got this because my NAD integrated couldn't keep up with my Dynaudio 1.3s. The Dyns are a very demanding speaker. My room is also very demanding since its acoustics are quite dead. I have bass traps on the corners, on the back wall, RPG and Sonex foam on the side and back wall.

The GFA-5800 had ultimate control over the Dyns. Bass was especially more dynamic and less distorted. It isn't harsh like some people say they are.

I really like the way I can turn up concert CDs to very high levels without breaking up. It stays well controlled even in the most demanding situations.

For the price I got the amp for, I would give them a 5.

Current System:

AH! Tjoeb '99 (tube upgraded)
Creek OBH-10 passive preamp (totally transparent for cheap!)
Adcom GFA-5800
JPS Labs Ultraconductor Interconnects and speaker cable
Dynaudio Contour 1.3
Premier J series 26" stands (sand filled)

I am currently using the ADCOM 5800 with:
Audio Research LS15 pre-amp
AA DDS III transport, AA DAC 3.O, AA DTI 2.O (outboard power supplies)
Martin Logan SL3s
High quality interconnects with a Audio Research balanced line from the pre-amp to the 5800

The amp has no problem driving my speakers which are not too efficient (1.5 - 4 ohms), but it is a tad harsh on the treble. I switched cables and they helped smooth it out. I think the tube pre-amp also helps this...

I have not tried other amplifiers in my current system so I can't compare, but the sound right now is stunning. Huge soundstage, extremely detailed and good, solid, clearly defined punch in the low end.

I should mention that this is the second 5800 I have had in my system since the first one fried out sending pure power to the left side speakers (and actually lighting one on fire!!!!). The exact same problem ocurred about ten minutes after Adcom supposedly repaired it which really pissed me off!!!

I demanded and received a new amp from the dealer and so far it has been fine. But I remain a little paranoid and not very impressed with their service department.

Barring another disaster, the sound is pretty damn good but I am planning to audition other amps when I have some additional $$.

Lots of power
Wonderful overall sound
Excellent dynamic range

Gets fairly warm

I absolutely love this amplifier. I bought it as a subwoofer amplifier for my DIY home project, to replace a GFA-555. I instantly noticed an absolutely huge difference. Every part of the sound is better. I immediately noticed a much fatter, warmer bass when compared to the GFA-555. I was so amazed with how much better it sounded that I decided to hook it up to my mains...I was impressed to say the least. I immediately greatly increased clarity and more pleasant treble not to mention the increased warmth in the midrange. I am completely satisifed with this amp. I think it's a wonderful amp in general and I think that for it's price, it's absolutely unbeatable. I HIGHLY reccomend this amplifier...I am completely in love with mine.

Similar Products Used:

Adcom GFA-555

Power, operates in class A for the first 25 watts(does ur amp do this?)warm tube like lushness to the sound, puts out far more than 250 watts. See review in Audio where it is a best buy!

fans

What a wonderful, musical sound. I absolutely love this Nelson Pass design amp. I saw the two page ads for years and wondered what it would be like to have it. But I was happy with my Yamaha 7 ch intergrated amp(list $1300.00 but I bought it discontinued for $600.00 out the door, because I NEVER PAY RETAIL FOR AUDIO EQUIPMENT, why should u?)I gave $980.00 out the door new in box from dealer dropping Adcom. I also picked up an Adcom 2535 amp at the same time for $238.00 o.t.d..Was he ever wanting to get this sold. Six months ago he still had a 5800 for sale in box. I use mine with Sony DVD 7000 into Adcom 600 DAC to Adcom 565 pre amp. I have the following speakers:
Polk- SDA 1A
SDA CRS
Snell-Type D, Q, KII, and a new system that was in the Home Theater mag in Oct. $7000.00 Snell system consisting of XA 75 mains(list $4200.00, I paid $2400 for demos), XA 55 center(list $1300,I paid $650 new), and 30sp rears(list $1500, I paid $740 new). This is a best for the money system. And with the 5800 driving the upper bass, mids and tweeters and the 200 watt built in amps driving the woofers what a fine thing it is. My Adcom 555II bi-wired to the center channel provides all the power one could ask for in a center speaker. My Adcom 2535 is a 4 ch 60 watt(two 535II in one chassie)or 2x60 and one 200x1 ch. in bridged mode. The rear Snells are made to work as a 7 ch surround system, so i could bi-wire the rears with the 2535. The TV is a new leftover Sony 53XBR45 (list at $4200, I bought it for $1480 because of a slight burn-in in the upper left screen. u dont see it w/widescreen movies.) This will help u understand where I'm coming from when I share my experances with u about audio in general. I have an urban legend to share with u. Here it is. "Adcoms sound foward and the high end is too much for my ears to enjoy". I bought my first stereo in 1967.

Similar Products Used:

Adcom 555II
Adcom 2535

I wonder if some of the people on this list were using the same amplifier I have. This is the Adcom 5800 right? I've owned mine since June 1995.
It's a superb amplifier and you'll have to spend at least twice as much money to get anything that compares. The 5800 drives my 3 ohm speakers with a warm yet detailed sound with a superb soundstage. Listening to good vinyl through my low output MC, it has an incredibly detailed, lush sound with excellent grip and control. Keeps me listening for hours on end with no fatigue. Acoustic music, especially brass instruments and strings, sounds so compelling my eyes pop open once in a while looking for the musicians.

I spent years looking for the right amplifier and now I have it.