New Adcom GFA-555 se - Special Edition

Adcom is making a new version of the GFA-555 II, the GFA-555 se. This amplifier is essentially the GFA-555 II with slight improvements including balanced inputs larger capacitors resulting in a better soundstage and an even higher damping factor. Did you know that the GFA-555 is likely the best selling piece of hi-fi equipment ever made, with a build of over 100,000 units? The GFA-555se will be available sometime in November.
dude, you should purchase an ad, not spam the forum
Will it be better than my Classe CA400 ?
I owned the original amp...boy was that ever a harsh sounding piece of gear and replaced it with a McCormack DNA night and day. I thought Adcom went out of business.
I used to have the GFA-5500 back in 1998 I think it was. For a mid-fi amp it was decent but I replaced it with a Conrad Johnson SA-400 amp and it was night and day. Of course as with most peeps in this hobby it just got uglier and What I mean is the upgrade bug keeps biting ;)
I owned several 555s and for the money,they could not be beat.Nothing else at anywhere near the price would drive my Infinity Kappa 9 speakers like the big Adcoms.BTW,I preferred the original 555 to the mk.II version;and,also liked it better than the 5500,5800 and 5802.With proper system matching and cables harshness was not a problem.

Lighten up on Power_Hungry. He likes Adcom porducts and is excited about this new prospect from them. We all have our preferences.

I hope Adcom is really making an effort to come out with a new improved product with great sound for the dollars. This is what got them noticed at first. And I did enjoyed my 500/545 combo I had many years ago. I kept it for a long time until I got sucked into the audiophile round-about.

Let us know if you get the new amp.
Mjcmt, my comment and observation is this post is the first evidence of Power_Hungry's existence (he joined A'gon the day he posted it), and it's worded as a blatant adcom commercial, not a query for input. It appears to me he's an Adcom salesman. Since he hasn't returned with followup comments I may still be right.

If I'm wrong, no problem - my post is out of line and I apologize. Actually, given it sparked interest of other Adcom fans, I'll beg your collective forgiveness.
Bdgregory: Well said, brotha man! (everything you stated)
Cut the new guy some slack! I believe Power_hungry is genuinely exited about the release of a new version of an old sort of classic. Adcom,for me while in high school and college, was a great bang for the buck. I had the GFA-535II and I even sprung for the $50 to change the faceplate to white!! I have since gone down the textbook audiophile money spiral and would now welcome a moderately priced great sounding power amp to experiment with. My 535II sounds OK driving a pair of JM Lab Alto Utopias at low volumes. It not the Mac 501's, but it is good for what it is.
Thanks for the info and heads up--i will be looking for the release of this new amp.
BTW: Adcom's website could use a little work!

When my cube (Carver) died, I went shopping. I was strictly at the low end of the $ scale.....and my hi-end store had a 555 on the used rack. Tempting, but ultimately no-go. I think it would have driven my panels fine, but I was a little timid buying something probably 15 yrs old....I didn't want to get into fixing something 'new' to me, especially given the dicey nature of getting stuff serviced. I have had to supply my own schematics, in the past.
That being said, if AdCom can get the old Pass juju going again, so much the better. 90% of the performance of the BEST you can get, for a fraction of the $ still plays well.
Bang for buck never loses.
Hey, sorry 'cause I am newly a member to Audiogon but I had to say something about this amp. I guess I need to spend some time here and say more about myself. I'm not yet familiar with the way things work around here. My intent was just to see what people think about this amp, I am somewhat excited because it goes back to the basics of an excellent well-proven design, I had one back in the early nineties and there has never been anything quite like it before or since.
welcome to audiogon Power_hungry. I apologize for misinterpreting your motives and post. Certainly there's nothing wrong with expressing excitement about a new, and/or old product.
I'm looking forward to the new Edsel.
I haven't owned any Adcom products, but I was very, very interested in a pair of Mirage M-3 speakers years ago.

I went to the dealer and listened to the speakers several times (he was driving them with a pair of Adcom 565 mono's).

The amps must have been pretty good....because the speakers sounded outstanding.

FWIW, I used to work for Adcom and I own or have owned one of every non-MOSFET amp made from the GFA-1 up to the GFA-565 monoblocks.

I was curious about this 555se - I cant seem to find any real information on it. How is the balanced input implememnted? The Adcom GFA-555 PRO (and the 565 balanced option) used opamps for balanced operation and they did not sound as good as the unbalanced input. Also, if this amp is a really a hopped up mk II, then it will have a DC servo and capacitor input instead of a directly coupled signal path like the original. The mk II, BTW, is not a Nelson Pass design, it is an "improvement" of the original circuit by two other designers.

I'm a big fan of the original 555 (only when modified), but I'm curious to see if the new Adcom can make this amp as much a value as the original.

Any more news on these? Has anyone actually heard one?
100,000 units/likely the best selling......? A testament to how deaf many people are. The Dynaco ST-70 sold over 300,000 units, because it sounded/sounds much more like music(even given it's obvious limitations). Now they sell used, for three times the original price(unaltered). Do the math with regards to which would, "likely be the best selling piece of hi-fi equipment ever made." Sounds as though Adcom was trying to resurrect the Titanic, hopefully with a smaller hole this time. But- that's just my opinion, and if you like the amp; you can have my share too.
Is every one aware that the new Adcom is not the same company it was in the '80-'90s company. It was bought out about 8 years ago and they moved from the east coast to Arizona. The new company was a digital company offered better HT processing in there products. I'm not sure how the new amps compare to the original company, but know they are made in China now.

I looked up the 555se on their sight. It states the 555 is class A. Is this correct? It may be class A, but only to a few watts before it switches to AB, I think. Does experience Adcom owners the facts?
I'm not sure how much weight "Special Edition" carries.

Wasn't there a Yugo SE at one point?

We all know how that ended.
I think the SE version adds balanced input and higher filter capacitance. They may have upper the quality on internal parts and added a toriodal transformer. All in all it may be smoother, more musical and less harsh than the original.
>All in all it may be smoother, more musical and less harsh than the original.<

That doesn't exactly raise the bar very high......

Agree with Mjcint -somehow the actual weight of the amp and 200W X 2 class A seems unlikely. Still -found a couple new at a good price -so I ordered two to drive subs.
Let us know what you think when you get it. What is the rest of your system that these amps will integrate into?
Wow. I just stumbled across this. I own a GFA555II which I bought as a demo in 1995. I've been happy as hell with it for years (presently in combo with a Mac C220 pre) but that doesn't mean I'm not looking at upgrading at some point. Surely "Edsel" is not an appropriate analogy. The Edsel was a bomb right out of the gate and the 555 was one of the best value purchases a mid-level audiophile could make for years on end. That technology would advance beyond it twenty years on is no reason to dismiss one of Nelson Pass's landmarks out of hand like that.

So I'm curious what some of the Adcom naysayers would recommend if my target budget is $4-$5K. My present inclination is to go with the Mac 252 as I like the solid-state/tube combination. My present speakers are B&W cdm7se and I've got the 803d's in my sights somewhere down the road.
B&W mate exceptionally well with Classe and Mac. No need to necessarily go with tubes w/ Mac power amps (unless you want to) as they use output transformers like tube amps do. I've heard the B&W/Mac SS combo and it floored me. Many swear by this combo or w/ Classe. Incidentally Classe uses B&W speakers to voice their amps so you have upped the ante w/ the B&W/Classe combo.
System :
Denon DL-301/II on a Slindy modified Rabco SL-8E mounted on a four pillar Slindy modified Oracle Delphi 2, feeds into a B&K Phono 10 -digi out of that into a Benchmark DAC-1 -into a ARC-90B and out a pair of Paradigm Studio 20 v-2's.
Have the Paradigm X-01 X-over - plan to just use the 801 woofers with a pair of GFA-555SE's to handle the bottom octave or two.Sold this version of 801's back in the day -my experience is they demand really powerful impedance stable SS amps- will be curious if the GFA-555SE's fit the bill?
"Wasn't there a Yugo SE at one point?"

Audiofeil likes car analogies, but hates sushi analogies!
I had the original GFA-555 from Nelson Pass Designs, in the early 1980's. That amp handled some of the most difficult to droive speakers, I had on loan. It drove my big ALON Model IV's and B&W SPeakers in stereo mode, 200 wpc, with no problem. I cant trash it at all. IT also lasted years, being left on all the time, till I sold it. I find the people trashing it, either didn't own one, or are jealous of it, not having to spend a fortune to get sound that they have spent tons of m oney for, and Adcom equalled or bettered theirs. Ray
I bought one used off agon as a fill in while my Proceed HPA2 was in the shop.... had to die when they where moving the factory so I had PLENTY of time with the Adcom.

Wasn't too bad at all considering I paid about what the tax was on the proceed to purchase the Adcom used. My brother had it for another 3 years powered up all the time, no issues. Co-worker now has it in his system.
My pair of 555se's came in - have a few hours in listening to them ( mostly driving the B&W 801/s-80's). Initial impression : 1.) despite being prejudiced in favor of balanced lines - the balaanced inputs on these do not sound good in my system.Very "trazitory" high end -not pleasant.Changed to the unbalanced inputs and all is well -very nice detailed highs and midds - no fatigue - what a modern transitor amp should do.
2.) Compared it with a Parasound A-23 I ussed to own. Very similar character - but the Parasound had a little more contol or grip in the bottom end when comparing stereo amps. Once the 555se's where run bridged - they did win the bass race.
3.) After a couple of hours pushing the not exactly efficient 801 series 80's to as loud as i want to go - both 555se's run bridged where surprisingly cool. Pretty clearly these are not running class A for more than a few watts.
4.) Nice amps - well made/assembled. Fit and finish are definitely up to par.As a tube guy - I am surprised how many really listenable transistor amps are popping up at reasonable prices.
As you know amps characteristics change many times through the breaking in process as the electronics settle in. I'd like your impression w/ balanced and RCAs after many weeks have gone by. During the night time hours and while at work use the various inputs (including balanced) playing a tuner through it at low volume. Do this for many weeks and change to dynamic cds later on. Do this with all the inputs and let us know after 3 wks of non stop running in. You will hear a noticeable sound improvement. Looking to hear your results.
Picked up one of these amps last week to match a pair of used KEF C20's I just picked up which need a high power/high current amp. My EL-34 tube amp just didn't match up well. After some hours of listening I'm pretty impressed. For a moderate cost solid state amp, it's pretty good and it sounds like it's got a lot left even at fairly loud volume. Not as transparent or "musical" as a good tube amp, but definitely not fatigue inducing either, and the bass is better, especially on the KEFs.

Mjcmt: It's not a class A amp. It runs pretty much stone cold at idle, and I've only gotten it a bit warm to the touch at the highest volume I'm inclined to listen at. Perhaps the marketing dept. did not understand basic amp classes and meant it was "Grade A" ???

Jim W.
Good to read about you positive assessment of the SE version. Keep us informed as it breaks in.
Thinking about the Class A rating, the amp could also have a Class A input stage then AB after that.
Minor update: While chasing ground loops -I gave the balanced inputs another chance.Not sure what's changed - but I am now very happy with what's comin in thru the balanced inputs.And at least i don't have to waste time with poor connections on the RCA side of things.
I'm curious, what does the rest of your system consist of?
I've had a 555 - original model - for more than 20 years. The only problem I've had with it is the power switch is in the On position.

It ran a pair of MGIIs and now a pair of Paradigm Signature S8s. It sounds fine - I've never had any complaint with it.

A truly amazing product for the money.
Have added a pair of very old B&W 801/series 80's ( first generation -not ported-no matrix) and the pair of GFA-555se's run bridged.-for CD use either a old Sony DVD changer or even older Marantz DR-700 fed into Benchmark DAC .Analog stuff is what i described in my 12-16-09 post.Oh yeah and I've got one of those great Sony XDR-f1HD tuners and some video stuff fed into a Marantz pre-pro - then out thru a state of the art seventeen buck RadioSchack A/D converter into the optical input of the Benchmark DAC.Not much into the video stuff.
Sounds like a nice system.
I had the Benchmark DAC and used it as a preamp directly into a tube poweramp. Wonderful!
Have you considered feeding your CDP into the Benchmark's coaxial input and the Sony tuner into the Benchmark's optical input. Then the Benchmarks output into your 555SE's to your B&Ws.
Minimizing the lower-end gear and having a better sound.
Have a old LG CRT hidef TV that can only feed audio out via Toslink - this goes into the Marantz pre-pro - which gets me a volume control and mute button - something my Benchmark doesn't offer via remote.Very focused on the best LP playback i can afford -CD comes next and the radio and TV/DVD sound is not real important to me.
Has anyone auditioned the 555SE versus the 555II or the original 555?
The orig. 555 II sold a lot of copies, and was a good value for the dollar. having said that, it would still just about tear your ears off with its harsh high frequency response.

I have worked on a number of the 555 II. They can be made to sound pretty good, but takes considerable work and a lot of parts........As others have mentioned, there are a number of SS amps of equiv. power that have much better long term listening characteristics.
Like a lot of people, I owned one of these for years and they were a great buy used but there is so much better equipment on the market for the same price now.
My personal experience with Adcom has been really bad.
I purchased a Adcom 5300 in 2001-2 to power some Martin Logans Aerius i. The amp was always used at low to moderate levels (8 to 10 max on the preamp volume knob).
The amp was getting so hot, you could barely put your hand on the top cover. I could have use it to cook.
Same with B&Ws speakers.
Same, and I can understand, with Magnepan, eventhough it was marketed as a tough beefy amp capable of driving any load with huge power reserves. I have sent the amp 3 times for repair. I have never been able to keep this amp running more than 3 weeks without issues. The third time, Adcom sent me a new unit. 3 weeks later, it gave up. I did not want to send it back a fourth time. And Adcom were so proud of themselves that they propose to take back the 5300 and sell me a 5400 30% off! I certainly did not want to heat my house with a 5400.
So I took the 5300 to the dump and the only regret I have is to have paid probably around $400-500 for it back then.
My guess is that in the late 90s Adcom took a gamble and got their stuff manufactured in China where consistent quality was non-existent at the time. Or worse there was a huge error in the 5300 design, which would demonstrate that Audio and amplification is really not what Adcom should do.

Heat generated from a power amp is not necessarily an indication that there is something wrong with an amp. Your amp may have been biased toward class "A", though I don't remember if my 5400 II ran hot or not. You have not experienced a SS amp running hot unless you run pure class "A" amplification from the likes of Pass Labs or others. You can't touch it for more than a second or so.

I actually liked my Adcom 5400 II very much and it was not bright in my system.
Biased toward class A is the explanation I got, but when I am saying it was hot, it was HOT, scary HOT. To the point that it was self-destructing every three weeks, and with plenty of air around it.
But when it worked, yes I found it to sound good.
Sounds like there was a voltage adjustment off the recommended spec. I had a vintage HK amp where one channel was very hot. After I adjusted the internal pots it was normal.
To Adcom 555 SE owners (power_hungry, stonedeaf, others),

Now that you have had your new SE version for a year or more can your comment on your impression of the sound on this amp as it has settled in your system. I've rekindled my interest in purchasing this amp.

i Just purchased two of these and intending to audition this week. i will let break for a while.
To Adcom 555 SE owners .. Any reviews?
Buyer beware-
probably made in china. If so, I am out.