Adcom?

I believe Kalali is right on the money , i have a Adcom gfa 555 mk 2 and paired it with a ss  audio research ls3  and later a rogue audio perseus magnum preamp (tubed)  retubed w/ nos holland amperex bugel boy 12au7 , and boy did that ever liquidate the music thru the adcom, also connected my  B&K 442 amp to both preamps, again the tubed preamp creamed the ss preamp in midrange up thru highs. Poor mans james bond stereo ! By the way i long ago owned a gfp 750 mosfet adcom preamp paired with 4 nad 214 amps in strap mono thru a pair of paul barton psb stratus gold spkrs, that was my first dive into uh hum high end audio, for a very poor man at the time. Had a micromega stage 5 cd player and a rotel rcd 950 , the micromega was better, but the rotel fooled me for the 1st and even 2nd listen , but the micromega just had better midrange , rotel more boom and sizzle which sounds enticing at first.

I happen to have a pristine GFP-555 that I am willing to sell. Contact me if you are interested.

I thought I'd update my experience with the new GFA 555SE.  Once again, my system is a Parasound Halo P5, 555SE, Schiit Bifrost Multibit, Nad cd player(C565BEE) and Totem Acoustic Rainmakers which are bookshelf speakers that can get harsh with some material.

Cables are Morrow Audio MA3 and 5 both with Eichmann silver bullets for the RCA plugs.  Tress speaker cable which is Totem's similar version of Chord Odyssey.  It's a better quality copper with silver plating.

Anyway, at the 40 hour + mark, the amp has really burned in nicely.  The imaging from the Rainmakers are jaw dropping at times and vocals have that extra sense of realism.  Bass below 80 Hz is routed to the Kef Q400 sub, and in my smaller room, it's plenty.  But the amp barely gets warm now when at first it would warm up a little.  I can't say enough about the black background to the soundstage, and dynamics and PRAT.

It's worth a listen for sure.

I drive a pair of UK made EPOS ES22’s with a ADCOM GFA 555, what really makes it sound special though is the Modwright SWL 9.0 SE pre amp. The GFP565 pre amp is good, but the tubed Modwright makes it really show me how good the GFA555 can sound. 

The GTP400 (tuner/pre amp) is one of the worst sounding pre amps Adcom made (tough to pack eveything in one box and still make it sound good,... GFP565 blows away the GTP400 in terms of SQ it has a great phono section too)


Matt M

https://www.amazon.com/Adcom-GFP-815-Stereo-Preamplifier/dp/B005Q36WXU/ref=sr_1_2?ie=UTF8&qid=15...

The reviews seemed to be mixed.  I was told by Adcom that another preamp model is coming out this spring.

My 1st post here. I've owned an Adcom GTP-400, & GFA 545 II since new around 1990. Thinking about upgrading the preamp & I'd like to stick with Adcom. Used GFP 555's seem to be around $350'ish, & 565's are $500 - $600. Adcom's site has their new GFP 815 for $399, but aside from a couple of threads on here I can't seem to find any reviews on it. Does anyone know much about this preamp?

I’ve owned the Adcom 555 since it was first made,bought it used. After reading a favorable review of a Musical Concepts Modified 555 in Absolute Sound I sent it too them and I had it modified. Very impressed with the results,gone was the grain in the treble and the bass had more slam and tighter. They made it dual mono too. I still have it in storage and I hard wired a Card as power chord into it.
I just got my Adcom 750 pre amp,a Nelson Pass design,back from Musical Concepts last month after having it modified to the Elite level and it sounds Uber. Sounds tube like with detail and warmth,very holographic with separation of instruments. I had owned the 750 since buying it from the first run with the Blue circuit board and Stereophile rated the 750 Class A.
Adcom was my first foray into affordable high end and holds a warm place in my heart.

The new models are almost entirely based on the classic models from their heyday, except with upgraded wiring and circuitry to meet current safety standards, etc.  Also upgraded circuit boards.  Still, the new models have improved specs in some areas, so it's obvious that some engineers are tweaking them, but Adcom only ever refers to their team of engineers.  No names are mentioned.

Earlier I may have given the impression that tubes are less than ideal in my opinion, but it's obvious that many love the sound and options of tube rolling.  I'm sure the tube sound would compliment Adcom amps, if one rolls that way!

I've got 30 hours on the 555SE at this point, and I've been changing cables and speakers as I go so it's hard to notice if the amp is improving.  But I'll tell you this, Ascend Sierra 2 speakers do not like Wireworld Oasis 7 speaker cables.  Strangest thing I've ever seen in my system.  A muted somewhat non-dynamic sound is the result, but swap in the Tress cables and everything missing is back.  The Totem Rainmakers are fine with either cable but do sound better with the Tress as well.

All in all though, the amp sound quality is quite good.  Open, fine imaging, air around the instruments without grain.  It's obvious why this design put Adcom on the map back in the day.  I don't crank it up in my smaller room, though, peaks of around 82-84 db are enough for me.  There's an old review by Stereophile floating around regarding the original 555 in which much praise is offered, and favorable comparisons with the high end gear of the day.  I'd say it's worth reading.

In this hobby I've made some missteps, and it's my hope to leave my impressions and results here to help others like myself who are looking for good options.  IMHO, these Adcom amps are a worthy contender unless you're looking to achieve that last 3-4% of magic in your system.  In that case, a reputable dealer with experienced staff may be your best bet, along with a much higher budget.

Any word from Adcom on who’s designing the new models ?

That's something I'm sensitive to, grainy or harsh highs.  I got rid of an Emotiva amp that got harsh at higher volumes and it drove me nuts because back then I was under the impression that all amps sounded the same.  I also had an Onkyo receiver that impressed me until I realized it sounded different than my main system.  Grain, I'd never heard it before and suddenly I realized that these audiophiles speaking of grain and such were on to something.

That's how I got turned onto Parasound.  Not harsh, just smooth full sound.   These days, for a preamp I've got the Parasound Halo P5 for the Adcom amp.  Not harsh in this set up.  But I've also noticed that the amp responds to different cables.  If I put in silver wire IC's and silver plated copper speaker cables, at least with my speakers it can get bright with some recordings.  With Morrow MA 3 and 5, and copper based speaker cables, there is no brightness.

I don't believe my old Parasound amp was as responsive to different cables, it's another way to fine tune the system.  I've heard tube components do have a different sound, but tubes are higher maintenance and such, not my cup of tea.

I've had a first generation 555II paired with a GFP-750 in my vinyl system for many many years and they've been completely trouble free, not even a blown fuse. I recently bought a tube preamp for my other/main system and tried it a few times with the Adcom and it really makes it sound much sweeter. My music choices have changed significantly since I bought the Adcom set and I also used to listen to my music much louder and always felt the Adcom got a bit edgy at higher volumes. With the tube preamp I can crank it up real loud and the music never gets grainy or harsh. Made me wish I had bought a tube preamp instead back then. Something you guys might want to try.

I have been a big fan of Adcom.  My first mid/hi fi equipment was a GFA-535 II amp and GTP-400 tuner/preamp.  Thirteen years later zi got a GFA-5400 amp and GTP-602 tuner/preamp.  I kept that amp for 13 more years until I got the GFA-555ms amp.

HIphile, thats funny! I actually did take the cover off, don’t tell Adcom, and looked it over. Those are the biggest 15000 uf caps I’ve ever seen, they were flat black and the name wasn't visible.  They didn't appear to be a high end brand.   As for others, I’m not familiar enough with Nichicon to recognize their caps. I didn’t look too closely on the 3 boards, though.

It did look all business in there, though, 8 bipolar transistors and 2 of the big caps per side with a large toroidal transformer.

Edlchiang62, thanks for that. I believe the 555ms and se and probably the same design, while the 565 and up start to employ other circuitry. I’m getting to be a big fan of the 555se.

I’ve been playing it at low level in an effort to break it in. I’ve read that science can actually document electron paths as they form, and caps need this time. At any rate, I’ve been switching up the cables to see if the 555se responds, going from mid level Morrow MA cables, and Silver Stager solids. I can definitely hear the sound getting more open with the silvers and Tress cable.

The Tress is Totem speaker cable, some kind of copper that’s silver plated and is 14 gauge. The two conductors are twisted together for the length of the run. Also, Wireworld Oasis 7 speaker cables. I’m running Ascend Sierra 2 and Totem Rainmakers, which are 4 ohm. Nothing big or even a tower right now, I’m planning on an upgrade in the summer.

Anyway, after tonight I"ll have 12 hours on the Adcom. I’d like to get 50 hours on it at least. Thanks for your thoughts all, I’ll update again when I’ve got more time on the amp.

schubert
I thought so too geoffkait. why I put it on here.

Really? It kind of came across like you believed it.

Geoffkait 12-23-2017
I’m pretty sure Lockheed Martín, Northrop Grumman and Boeing are quite capable of building aircraft electronics.

As a former employee of the electronic systems division of Northrop Grumman I can confirm that this is correct.

Regards,
-- Al
 

213runnin I purchased the GFA-555ms this past July.  I like it very much.

at half the price!

213runnin have been curious to take a glance at you Adcom's guts? Read somewhere that it there's some Nichicon Gold caps inside! I'm planning on buying a Van Alstine power amp after listening to his pre amp, but this Adcom power amp is temting

I thought so too geoffkait. why I put it on here .

FWIW The B&K st-140 was a  total copy of  a Van Alstine amp of the day .

A bit off topic, but I thought I'd share this.  I recently picked up an old Adcom GFA 5400 and it isn't nearly the equal of my McCormack DNA .05 Deluxe amp, but it sounds very good.  I found no fault with it -- perfectly musically.   The mosfet design of it lends it to upgrades and I have a tech upgrading it to the nth degree to see what it is really capable of being.  The bones to the GFA 5XXX line of amps, designed I think by Nelson Pass, are quite good.  In the stock unit, I heard no edginess in SQ.  It clearly does not have the resolution of the more expensive amps.   

Sounds like someone’s been watching too much RT TV. I’m pretty sure Lockheed Martín, Northrop Grumman and Boeing are quite capable of building aircraft electronics. In fact I imagine there are laws prohibiting the use of foreign made electronics in “front line aircraft,” especially the classified ones. If it doesn’t make sense it’s not true.

I read an article lately that US first-line fighter planes have electronics not made in USA because no one builds them here .

Yep, Taiwan it is.  I do like to support domestic manufacturing, but am a realist when it comes to electronics.  How long have you had the 555ms?

Last night I heard a song from Johny Cash's American recordings, just his gravelly old voice and an electric guitar to start.  Simply amazing, space, realism, and that sense of live music in the room.  Not bad for a 'budget' amp.

My GFA-555ms is manufactured in Taiwan which makes me feel a little better.

Well, it's a 200 wpc amp that retails for $1299(currently on sale).  Would you care to hazard a guess?  I'll pull it out of the rack to check the back plate at some point,  but I'm betting it's not the USA.

I got the 555SE today and did a quick audition only as I'm busy, but will have more time on the weekend.  In short, this amp is the real deal.  Dead quiet, imaging, separation of instruments and dynamic, it's the whole package.  I'm running it with the Halo P5, Morrow Ma5 cables, and decent Wireworld speaker cables.  A Bifrost DAC and Nad C565BEE cd player, so decent supporting gear, but I am impressed with this amp.

On power up, all you hear is a little relay click as the amp comes on line, and of course the house lights dim upon powering it on.  There is no 12 volt trigger so you have to turn it on manually, but I think I can make an outboard box that will accept the 12 volts from a trigger cable and power up the amp using a relay.

Adcom has been pretty quiet the last several years, so it's nice to see they can still put out a great amp.  I'm replacing a Nad C375BEE and I've also had a Halo A21 a year ago.  Oh, and the 555SE sounds better than the GFA 5400 I've got too, though that amp is 19 years old.

I acquired a Sansui receiver a few years back that was 42 years old, but sold it a year a later.  I could not believe how nice it sounded.  The model number was 4000, and it made my Onkyo TX SR876 sound boring.

Anyway, I should have the Adcom 555SE by Saturday.

If you had any amp for 39 years it had problems long before that, you just  don't pick up on it as it is a slow process that you become accustomed to .

Ed, if the 555ms doesn’t have the turn on thump, then the 555se won’t either I expect.  Good to know.

 I've been using a Hafler DH-200 for 39 years and it finally has developed problems. I want to replace it.

John Hillig is your man

http://www.musicaldesign.com/MC_AdcomAmp_mods.html

My new GFA-555MS amp does not have the turn on thump, while my older GFA-5400 did.

Thanks, kjl, too bad Adcom didn't spread the word on the cfl bulb issue.  I actually communicated with them directly when I was considering whether to get the first pre replaced.  

As for turn on thumps, I think most of the older Adcoms did have a turn on thump because Adcom didn't have speaker protection.  On the current line up, I think it depends on the model, because I've noticed that their higher up models mention speaker DC Servo and OMRON 20 Amp speaker relay protection circuits.  At least the GFA 575SE.  

I'll be receiving the 555SE in a week or so and can report back, but I'm fairly sure it'll thump upon turn on.

I have a question for all the Adcom power amp users. Do any of the Adcom amps generate audible turn-on or turn-off transients? Transients (pops, thumps, whatever) are particularly annoying for me. I've been using a Hafler DH-200 for 39 years and it finally has developed problems. I want to replace it.

Regarding the volume control on the 710 preamp being affected by a CFL...the answer is yes. When I bought my 710 years ago I had the problem but after a couple days I realized the volume control would only go nuts if a particular light was on in my family room. It was a CFL bulb. I change to another brand of CFL and the problem went away.

I once owned a Audible Illusions Modulus 3A. Very good preamp. I wasn't using it for it's phonostage, which I believed to be a waste of a fine stage so I sold it. Went line level. 

@ mesch
It does pair well very well with the Adcom. The Adcom can sound a bit edgy, especially if not given a long period of warm up. Dollar for dollar though, the Adcom sounds pretty darn good. I had the Audible Illusions paired with a friends Ayre V-5xe Evo for a couple of months and the sound was incredible - very smooth and detailed, with a beautiful large stage.
While not quite in the same league as when paired with the Ayre or the Brystons, It’s always good to know - I can count on the trusty old AI and the Adcom to keep the music flowing, if something else lets me down...Jim

Jim, I bet the Audible illusions with the Adcom amp was a great pairing. The pre likely smoothed out some of the grain in the high end of the amp.

I have a US made Adcom GFA 5500. I picked it up used several years ago to back up my Krell that could not handle the fluctuating power issues in the area where I lived. While the Krell shut itself down every time the power spiked or dropped by a few volts, the Adcom had no problems. It may not compete sonicly with some of the much more pricey gear out there, but, with a long warm up, it sounds pretty darn good and is as tough as a tank. It's still my trusty back up and am using it now while waiting for a new set of tubes for my Rouge. I don't know how their new stuff is, but the older US made Adcom gear was some of audio's best bang for buck ever out there. Allot of my audio gear comes and goes, but two pieces I will always keep are my 35 year Audible Illusions, tubed, pre-amp and my trusty Adcom.......Jim

Yea it looked like a much bigger amp. Handles were cool. I owned mine for 25 years. 

I thought the ST-140 simply looked cool…the proper satin finished handles…just cool…besides being an inexpensive and well regarded amp.

Yes, Adcom was king of power for the money back then. I believe B&K made the smoothest SS amp for the money at that time for speakers not needing excessive power (st-140).

Those were the day's when Adcom was the king of power for the $$$

I've owed a few NAD`s  my first one was the 7600  receiver bridged   with a 2600 Amp i loved them both for many years
Now i have a pair of NAD`s Amp's S-200 and the Pre Amp S-100 that power my SDA Flagships they sound great together IMHO 

I have an Adcom 5800 ( Nelson Pass) design driving Magnepan 1.6 speakers with ease . No issues except the slight hum from the two cooling fans. Don't know when this unit was produced, but it is built like a tank. It sits in my closet now as I switched to Bryston.

anyone know who's designing the new Adcom ?

I'm with mattmiller: the Adcom GFA 555 was (and still is) a great bargain-priced amp (used) and perfect for the entry-level audiophile or for someone who wants a decent 2-channel amp for surround speakers. Another great buy for the audiophile on a budget (again, used) is the Muse Model 100, which is bullet-proof and great sounding. It's my current center-channel amp. I even have a B&K ST-140 sitting on a shelf somewhere, my first one-step-up from receivers amp back when we were poor but knew there had to be something better than what Sears was selling. If one of our Levinsons gave out, I could live with a used Audio Research tubed preamp (e.g. an LS-15 or LS-16) and a Muse Model 100 until I had saved enough to buy another beefy Mark Levinson amp. I'm sorry to read that Adcom and B&K are not making reliable, great-sounding gear any more. Go used! Audiogon is a life-saver for those of us who are not rich but still have good ears.

Like Adcom, B&K is back in business as well (http://www.bandkav.com/products/). Looks like in name only. Probably the same level stuff as adcom. I'm guessing Emotiva is probably the modern day equivalent. I ran the B&K st-140 amp for a few years and it sounded wonderful

The newer Hafler gear looks interesting http://www.hafler.com/

I've always had a big adcom amp lying around for spare bedroom use or something. They were my first intro in to good sound...a good starting point for people who love to listen to music. The early stuff like gfa 555 and gtp preamps are bulletproof, the later stuff is not built as well but sounds decent...not really true "audiophile" but good sounding and powerful, reliable.