I owned the 5400 for two months, having purchased it to replace my 545II, which I had been using for years. Compared to the 545II, the build quality of the 5400 is average at best. The sound was unbearable, especially in the lowertreble and upper midrange, when I first hooked up the unit to my Snell E/III's.
I gave it awhile to break in and found that the sound only worsened. In contrast with the 545II, the sound of the 5400 is harder, steelier, grainier, and totally non-dimensional. My wife found the amp "painful" to listen to at even normal listening levels. I cannot speak for all Adcom 5000 series products, but having owned the original 555, the 555II, the 545II, and the 535II, I do not feel this new FET design is a step forward for Adcom from the bipolar 500 series. What may have happened here is that Adcom could no longer afford to make the 500 series amps at the price points they wanted to stay under, and so they were forced to come up with a design that is cheaper to manufacture. Why else would they give up on a bipolar design that was so successful? I was looking forward to a Mark III series of 500 amps. Instead, they changed to FETs which demand fewer stages and thus allow for a more "purist" design as Adcom puts it.
Fewer stages saves on cost, as do cheaper chassis design, flimsy binding posts, and an even wimpier power cord. I used to buy Adcom products ( I have owned or own now almost every Adcom product made prior to the new line)
without even listening to them. Foolish, I know, but that is how much I have trusted Adcom over the years. The 5400 is a real let-down. I went ahead and bought a McCormack DNA-0.5 to upgrade my 545II and sold the 5400. If you currently own any 500 series component, I highly recommend that you hold on to it, even if you don't have a current use for it. I wish I hadn't sold all of mine. I have noticed lately that 500 series pieces are demanding higher resale prices than ever before, even though they are older. I don't feel there are any
components being made today that compete in build or sound quality with these Adcom classics at the prices they were originally sold for. Maybe Adcom is currently doing what Coca-Cola did with "New Coke". I am praying for the return of "Original Formula". I doubt that will ever happen.

I had have the 5400 for over a year. I can agree with Ted Neff that the Adcom, AT LEAST IN MY "BOTTLENECKED" SETUP, is steely and painful to listen to for long periods. I have not yet stepped up to a serious CD player- mine is an aging and inexpensive JVC. I also have (questionable) Monster Cable series 300 interconnects and "cheapo" Monster $1.50 per foot speaker wire. On the other hand, my pre-amp is the Stereophile-acclaimed Adcom GFP-565, and speakers are the huggable B&W DM602's. But still, a bottleneck is a bottleneck if my CD player and cables are the culprits behind the steeliness and ear-pain (even at moderate SPL's).
Take my rating with a sprinkle of salt. I would value your input on the matter of wires and interconnects. I have pretty much decided to give the Marantz CD-63 a try. Are my cables, coupled with this amp, killing my ears?

An update to my previous review (see below)- I upgraded my cables to Transparent MusicLink Plus and MusicWave Plus. I also replaced my junky CD player with a Rotel RCD-971. EACH of these excellent upgrades made very noticeable improvements. Bass is VERY deep and the music is FAR more layered and SMOOTH.
Other variables being ruled out, I hear certain faults which I attribute mostly, if not exclusively, to the Adcom amp. Very dense music passages, such as choirs and orchestras, are congested. The soundstage is also low to the floor. Vocals still sound a bit grainy and harsh, but this may be more the recordings than the amp itself (I am discovering that it is as difficult to find top-notch recordings as it is to fnd top-notch equipment, regardless of cost).

However I do NOT knock this amp. It certainly has shortcomings but only in comparison with much more expensive amps. Even so, I have read reviews of high $$$ SS amps that have these same problems. Perhaps this is why tube-heads are so adamant. However I am not about to put up with the fussiness, cost, heat, and out-of-control bass of tubes (I have a "Bach to Rock" library that DEMANDS punchy, controlled bass). The Adcom has a tremendous amount of punch, it images well, and the build quality is good. Despite its flaws, this amp is an excellent value.

4 stars for performance within its price range.

I have had no problems with this amp and I have owned it for two years. Great sound for the money!

Complementing my HK-8450 CD player, GTP-550 pre-amp and Castle Harlechs the 5400 sounds excellent to the novice audiophile. The bass is deep and responsive whether playing classical, jazz or John Spencer and the Blues Explosion. I have a large living room w/ high ceilings and this speaker fills the void at low or high volumes. The impressive aspect of the amp speaker combo is that at moderately low volumes the bass still fills the room, which is just lovely. The family does not me to permit me to listen the system at high volumes very often. But when those times permit, the sound remains pretty tight. My only criticism is that the sound gets somewhat bright at high volumes, but someone with a better ear and more experience might say otherwise. In my opinion, for the money the 5400 is an excellent value (especially if found used or as demo).

I have two Adcom products.....the GFA 5503 and the GFA 555II. I use them to drive five Coincident Speaker Technology Triumphs all linked by the new Lexicon DC-1. Let's just say that X-files ROCKS! with this set-up. And music...what amazing sound...With the Lexicon one can literally walk around within the sound field and hold the the 3-dimensional experience from a huge soundfield. (I use the Sunfire True Sub to fill out the bass). So why am I writing? Simple. I found two major resources very helpful. There is a wonderful audio magazine call The Sensible Sound that is published four times a year. The idea is to evaluate top gear with reasonable prices....and they cover the full spectrum of audio equipment. Highly recommended. The other is the Audio Trading Times.This is a publication that lists used products directly from the owners. You cut your own deal and delivery. I picked up a three year old Adcom 555II for $425 delivered to my door........absolutely primo condition. So, My only beef about Adcom is the "thump" when the unit is turned on. Other wise, I think these are the last amplifiers I am going to buy. So, since I can't rate the 5400 specifically, I will give my rating to the Adcom company (and look for some great used equipment deals...be careful...and sometimes you find a real jewel at wonderufully affordable prices. WFS

My system is all Adcom, GCD700 CD player, GTP450 preamp/tuner, ACE515 enhancer, all hooked to a GFA5400.
Speakers are B&W P5s which require a min of 50WPC and
quoting "what Hi Fi Magazine" "need a good amp to be heard
at their best." THe GFA5400 is doing an excellent job with
these speakers.
n .

Powerful, quick, firm control over the speakers

None, especially at this price level

Since buying this amplifier second hand, I'm more and more impressed with it every day it's in my system. It's built like a tank and while it does heat up (it is heavily Class-A biased, after all) it always delivers excellent performance. I haven't been able to get the temperature-alert or excessive-distortion LED's to light up, but I've tried! I have no complaints about the build quality: the power switch is firm and reliable, the rubber screw covers on the sides have stayed in, and what's more my amp came with the detachable power cord! (do I detect an upgrade path?).

In combination with the GTP-450 pre-amp which I also bought used, I got a big step up in sound quality from my previous Onkyo receiver. The sound is very clear and dynamic, and the treble has a lot of air without being grainy or piercing on my PSB Stratus Silver speakers. The bass is deep and well-controlled (I don't use a separate subwoofer). Music is now presented on a wider soundstage, and the location of players and vocalists (image focus) is much much sharper. With sources off and the volume all the way up, there's no noise or hiss.

I auditioned the GTP-450/GFA-5400 combo against the GFP-750/GFA-5802 at the local audio salon and I was surprised how little the 5400 gives up to its top-of-the-line sibling. I don't think I would need the power of the 5802 unless I had a much larger, heavily damped room with inefficient speakers. I've also compared the 5400 to amps that are supposed to have a "sweeter" sound, like Rotel and Classe'. IMHO they sounded slowed-down and uninvolving, with a lethargic pace that doesn't suit rock music.

I'd recommend this amplifier along with the Adcom GTP-750 pre-amp for anyone who wants a sample of audiophile-quality sound, "for not much more than the cost of a receiver" as the ad says. I've become so sold on Adcom that now I'm saving up to replace my aging Sony CD player with the Adcom GCD-700!

Similar Products Used:

Yamaha, Onkyo and Sony

Fast punchy bass, Detailed, Good soundstage, Good resolution with low distortion and noise for an amplifier at this price.

The detail can become bright in the wrong system. If you have a warm, laid back cd and/or preamp this is a good amp with a good amount of power. It did well powering Vandersteens which are 87db sensitive. THIS AMP RUNS HOT!!!

This amp radically changes sound with the interconnects that are used. Silver interconnects can sound very harsh and digital with the wrong front ends. It is worth playing with speaker cable and interconnects to get the "right" sound. The brightness also diminished significantly with the addition of an Audible Illusions tube pre-amp. However, utilizing a Parasound preamp drove my wife out of the room. The bass was overpowering and the sound was so harsh that even low volume listening sessions only lasted 15-20 minutes. Sometimes I miss the detail, but in my small listening room it was too bright. One thing I do miss is the fast bass. It was quick, punchy and sounded like it had alot more than 125w/channel. Another thing to consider is if you need to heat a small area of your home--this amp is for you. This is what you get from class A circuitry and from my limited understanding that's essentially the Adcom's architecture.

Similar Products Used:

Parasound, Jolida, NAD, and B&K

My system :
For source I use a Rotel RCD-970. This player is hooked up to an Adcom GFP-555 II by a pair of Audioquest Ruby's. The Adcom GFP-555 II is then hooked up to my GFA-5400. I compliment this setup with a pair of Definitive's BP-8Bs which is wired also by Audioquest, Indigo.

Initially before deciding on which amo to use for my system, I was listening to Rotel. Rotel is said to be an excellent amp (most of my friends use Rotels-either multiple of single). Hooking up the Rotel, Rotel RB-980BX, and after hours of listening I find the Rotel in comparison to the Adcom, to be too smooth. The Adcom GFA-5400 has a very warm, bright, detail quality to it. Moreover this amp has a very good soundstaging and imaging quality to it as well.

The built however is a bit less than desirable. My first impression of the amp was quite good. I loved the horizontal lines on the face of the product and the little warning leds on it. However, I was very upset with the power button. The button was bit hard to the press. I wished it was a bit more "springy".

On the whole I don't think I have an excellent system, but my system is very satisfying. This is in part due to quality the usage of good equipment... Adcom.