I just got done reading about the new Adcom line of amps and from what I could see their design is a far cry from the minimalist approach of the original GFA"s. I have a modified 555 from yesteryear which I tried several months ago when I sent my reference amp in for a rebuild (20 year mark). Unfortunately, even after giving the old Adcom a few weeks to settle in, the music just was Blah. I boxed it back up and went to headphones and Spotify till may SMc amp returned.
I would be very curious to listen to the new line. I would imagine that many component improvements that have occurred over time are implemented in the new amps. I would be sure to get an extended audition at the local audio emporium or better yet in your system to be sure the Adcom is up to the performance of your other gear.
I talked with adcom a while back and was told this was based on the old design with some mod and upgrade to the overall design. I just brought my daughter an adcom redone by the seller. don't sound to bad. a little thin in the bass though....
I have conrad Johnson gear for me and my wife, was just curious for my other daughter.....
I have an Adcom amp coming in next week. It is the least expensive 6602 amp. It is a temporary amp until my main amp is finished being rebuilt (Forte' Model 3). The price was right, but I am also curious as to what my reaction might be. I didn't want to buy an older amp just because of the 'wear' issue. Likely, this amp will be used in my garage system, unless it surprises me greatly. Go with your ears.
what gear including cabling is in your system? Happy Listening!
let me know how that turns out for you...…
my wife has,
conrad Johnson 2300a recently redone by hamad at amp surgery
conrad Johnson pv10l
my old technics turntable
and I switched her to tara labs interconnects from audio art for a more open sound, I made the speaker wire from bulk axiom wire.
again conrad Johnson
pv 12 pre, recently redone by hamad at amp surgery (sounds like the classic now)
oppo 203, (had to give up on my beloved rotel 975)
acoustic zen interconnects cable, (personally from, I call him dr zen,(Robert lee), more open forceful sound, gave my tara labs to my wife.
I make my own speaker cables...….. holidays over jafant.
Let's see, I mostly use CD's, so it usually starts with a Rega Apollo, then moves on to a Vincent SA-31 MK pre-amp. From there, one output goes to a NuTube headphone amp that I built and really dig. When the amp arrives (Adcom 6602) it will power up a set of Decware ZOB speakers (Zen Open Baffle). I am pretty picky about power, so I use a BPT isolation transformer that produces balanced power from six separate secondary windings. Power cords vary, but PS Audio Preludes, Pangea AC14 SE, and one from BPT as well. Speaker cable has been Maple Shade basic twisted cable, which I have always liked, and interconnects are Nordost Blue Heaven from the CD player, and one Audio Magic from the pre-amp to the headphone amp, and then Straight Wire from the TV to the Pre-amp as well. I occasionally use a dedicated a small laptop set up just for sound reproduction by a friend of mine, and it is amazing. That's about it.
Very nice systems and cool that you make your own SP wire.
I would beg to differ with hifiman's assertion that he's read up on the new Adcom lines. There is almost nothing to read up on regarding them or at least their design. One can read the manual of each model on line, or read up on a few owner's impressions here and there, but there is no analysis of new vs old design, spec, sound, etc. that I can find anywhere.
That said, I bought the 555SE a year ago and the 6002 a few months back. The 555 is a gem for the money. Clear, open, dynamic but not bright or harsh sounding, or at least with decent cabling. Great soundstage too. I may actually be holding it back somewhat with the preamp, a P5 from Parasound. it's a decent pre but employs mostly op amps instead of the preferred discrete circuitry. Still, I have been able to get a soundstage with depth at times,
The 6002 is a budget amp and though not the equal of the 555, has lots of power for its size. It actually has more features than the 555SE, which may be due to the 555's minimalist design with no 12 volt trigger or input gain knobs.
As to the OP's curiousity towards the 575SE, I'd be curious too. At 81 lbs, I'd suggest it's not for the faint of heart! The 565 intrigues me too at their sale prices, but I've got to lay off the amp upgrades for a while.
hey thanks 213rinnin,
that's what I figured, it was a great line in its day, I don't see why it don't work now...…….
Sure, no problem. Being that I've owned both Parasound and Adcom previously, I compared some of the specs of the 555SE and the Parasound 2250 V2. They retail for about the same...
The Adcom has comparable SNR and better damping factor(900 to 150), better THD and better frequency response, which is down to 10 Hz vs a -3 db of 20 Hz for the Parasound. The 555 also doesn't need a 2 ohm switch to be stable at 2 ohms. I can't find cap values for the 2250, but comparing photos, the Adcom's at 60,000 micro farads seem quite large compared to the Parasound.
One more thing. The 2250 achieves unity power at 1 volt, which is the typical max voltage output for receivers, but not preamps. The Adcom achieves full power at 1.75 volts, which would give more range on the volume dial.
To be fair, the Parasound has more features, consumes less power at rest, and has 275 wpc on tap vs the 200 wpc for the 555. The new improved Halo amps look much better for more money, though.
I got the 6002 in yesterday. Two things stuck out immediately. First, I was right about the better damping factor helping out the bass response compared to my old tube amp. No surprise there, but I do like an accurate bass. Secondly, the amp has a harshness to it that I am hoping will go away with a few hours of use. In general, it is an honest sounding amp to my ears, so it would be worth using for the time being, until my Forte' amp is rebuilt.
That's an interesting result, the harshness I mean. I found it not harsh with Totem Rainmakers( a somewhat forward/open sounding speaker), but perhaps the Halo P5 had something to say about that. Then too, my definition of harsh may be different than yours. My cabling differs too, but let's not get into that!
I suppose it is a budget amp after all, you can only get so much SQ at the price point.
how is the ummp factor, I had one rebuilt (555) and its clear as hell but a little lacking in the bottom end. im thinking that will go away at break in as well..
Guys, both of you make good points. Mostly, I know that what I am hearing is really due more to the combination with my speakers than the amp itself. I am referring to the single driver speakers that I am using from Decware Audio. So many things I like about these drivers, 'but' there has always been a certain frequency that shouts (in the midrange). With tube equipment, it was tolerable, but now that SS has the floor, there is less forgiveness. After pointing that out, I am willing to say that this little amp is well worth the money. Like I said, the damping factor improved the bass to my ears, and overall, I find a good open presentation. The ummp factor can be had, but mostly at higher volumes. Maybe a bit more break in is to be considered. Only a few hours on the amp so far.
I must point out one feature of the amp that is cool. It can be set to standby mode, and then if a signal is sensed, it will turn on. No need for a trigger, although that can be used as well. Small thing, but appreciated
I will be moving on in a couple of months when the larger amp is rebuilt, and that is where I hang my hopes.
Been listening to the amp for a bit now, and I like what I hear. For my ears the sound is more transparent. I wouldn't put it heads and shoulders above the previous tube amp that I had, but it does more things right than wrong. As for the harsh sound I first heard, I have determined that the speakers are more at fault than the amp. The solution was unusual but it works. I had another driver that was being used for bass, being fed by another amp. I disconnected it, and then wired it in series with the original driver. I am now listening to the set up and so far, I like it. The harshness is practically gone. It will take a bit more experimentation, but I feel that the speaker idea is on the right track.
It's a couple of weeks later, and I've sold a few things and acquired a pair of Totem Hawks, as I've mentioned elsewhere on this forum. I bring it up here because I've currently got the 6002 driving them, and it seems to be doing fine which somewhat surprises me.
The Hawks are apparently a difficult load, and I had the 555SE running them, but was concerned about the driver movement at higher volumes so swapped in the 6002. It's a fun little amp, though not quite the equal of the 555 SQ wise. Love the Hawks, btw, I'm going to sell the Rainmakers.
I have to agree about this little amp. I too, am surprised at the amount it does right. Yes, of course, I have owned better amps and combinations of gear. The real point here is that I have no reservations in the meantime of getting the new amp project that I am in the middle of, done ASAP so I don't have to listen to the small Adcom anymore. I may even keep it around for a garage system. That's not a slam either. It would be great to have something decent for shop time.
I currently have a New GFA-575 in rotation for audition with a PS Audio BHK Signature Preamp, PS Audio PerfectWave Dac. - Bridge 2 Network card playing through Focal Sopra No. 2 speakers in a listening area of 15' X 20'. After several hours of break in time letting things settle in here are my thoughts.
If you are looking for a quality amplifier with massive amount of power and current Than this might be the amp for you. Weighing in at 81 lbs and a whopping 350 Watts at 8 ohms 450 at 4 ohms and 900 watts 8 ohms, bridged then this will be an extremely hard amp to beat!
I would like to start with my background as an audiophile and share some of the listening experiences with you as I have owned and Auditioned many High-End Class A, AB, D, & Tube Amplifier Companies such as Mark Levinson, Dan D'Agostino, Pass Labs, Krell, Classe, Audio Research, Cary, Gryphon, Luxman, Plinius, Block Audio, PS, Audio, BHK, Hegel, McIntosh, Krell, Bryston, Octave, Parasound, Emotiva, NAD, Adcom and much more!
After break in, this amp delivered a large sound stage with transparency, notable highs and mid range. The amp had very good detail in the background as well as a punchy tight bass that could also drop down very low. In all I would highly recommend this amp over all for its price to performance ratio again will be extremely hard to beat a 2X the retail value.
Hope this has been helpful.
thanks bluemartini for the followup, after a while the adcom 555 really opened up. I started driving it harder to break in. sounds great. real excited for you and the new adcom gear. but fell into a McCormack dna 500 and a brand new conrad Johnson et3se, im in hog heaven now. I still have a extra system to get rid of, since I gave my daughter my wifes cj 2300a and pv 10a she had. gave my wife my cj 2500a and the pv 12. I have a acurus system left …….and I prefer a dirty martini, shaken not stirred...….
I might as well update the thread WRT my adcom GFA 6002 amp. I ended up taking it to my workplace running a pair of Totem Dreamcatchers which are a 4 ohm speaker. The little Adcom has driven them effortlessly and the pair produce a good soundstage.
I use the signal sensing turn on for the amp and it's been flawless thus far. I'd say Adcom has a good handle on quality control. It's nice to hear that the bigger Adcoms are such great performers.
Got to give praise to Adcom for hanging in there and stepping back in to the HiFi Ring. I’m impressed that so many people still have the older amps and that they are still alive and kicking. The new 2019 amps have stepped to the plate adding beefier, higher quality internals, at this price point I must that it is an amazing buy for the money :)
I agree with you both, adcom was a giant killer in its day, nelson pass was their chief designer. great amp at a low cost. only john curl with parasound is still doing that. cause everyone else is going crazy.…..
I have played with this amp adding different component cocktails and I must say it is one hell of a deal for the money! Get the right speakers in front of this amp and lookout! The Adocm GFA-575SE has a Hegel H30 sound flavor.
I will be adding a Shunyata Denali 6000T into the equation with the Adcom 575SE, PS BHK Signature Preamp, PS Audio DirectStream Dack playing through Focal 2's. and give you my thoughts soon.
I have own the Adcom 545ii, 555ii and the 565ii. I have my 565’s modified by Musical
Concepts. They sounded pretty good driving Maggies. They matched very well with them. Also Nelson Pass made a comment that a couple certain parts were changed out from his original design. He wasn’t very happy about it. Said it held the amps back. Many over at the DIY have modded them using parts Pass suggested with great results.
Well I’m currently after an Adcom 565SE, Nelson Pass notwithstanding. Problem is, it’s on the other side of the country, and the seller would prefer to keep it local.
I’ve told him to let me know if he decides to ship. He’s got the shipping box but has had bad luck with shipping items, and the 565SE is 50 lbs.
I read an owner’s impressions of the amp and he says it’s on the foreword side of neutral, which would be different than the 555SE I had. Anyway, I regret selling the 555, and hope I can snag a lightly used Adcom eventually.
Happy holidays, now that we're past Christmas. My aim has changed as the 565se owner didn't get back to me. I made an offer on a 555ms here that got accepted, so I'll probably get my hands on it in the next couple of weeks.
I remember a poster here who had one and was happy with it, but my main curiosity is the sound signature and whether it's neutral or forward sounding. It reaches unity power at 1.25 volts, so should be a good fit in my home theater being fed by a Denon avr to my front speakers.
But I plan to put it through its paces first in the 2 channel rig. I'll report once I get some time on it.
Well, another year and for me, another Adcom! I almost bought the 565SE last year and it's been in the back of my mind, though I've been happy with the 555MS.
But I always wonder what if, and found a pretty good price on BNIB. I probably won't have it for a couple of weeks, but I'll try to give my impressions then.
So the 565SE came in a little bit early and I’ve been burning it in. I have about 6 hours on it so far. This amp is the little brother to the 575SE, according to Adcom. Same topology which differs from the 555 SE AND MS, and I’ve had both of those.
But the 565 is a different animal for sure. It feels like the power is limitless compared to the 555 MS, and the sound is starting to come into its own. Female vocals are a high point already! I’d like to put 50 hours on it and then we’ll see if it’s most of the way there.
My speakers are recent too, some energy CF-70 that I got for a song on Black Friday. They are not the equal of my Tannoys and Totems, but can handle the 250 wpc, and do bass pretty well. More to come...
Remember visiting my brother in law in 1992 or 1993, in orland park, Il. A small very nice shop “simply stereo”
ran by two of the most relaxed and nice guys, mike and joe.
Knowledgeable and straight shooters, no push to buy, auditioned for me everything I asked.
Had the adcom mono blocks hooked to the klipsch corner horns, that was bad, searing highs, bad!
Switched to a pair of paradigm towers, and it was great!
Enjoy the hunt.
I would try them, do they have a trial, 30 days or something?
if u don’t like them, return.
I always wanted those adcom amps, but $ was my issue. Ended up buying the onkyo m504, which i blew up,a few years later.
As far as I know, there is a dealer that has an ad on audiogon that offers a money back guarantee if you don’t like the amp. I’m not going to give them a plug though, it’s easy enough to find the dealer.
At the end of the 80’s I remember drooling over Adcom adverts in the Stereo Review magazine, but I was a poor student and never saw them on the shelf until I bought my first in 2000. I loved that amp...
BTW, if anyone is curious about the bigger 575SE, it has a total of 132,000 micro farads, which is pretty crazy. Also, 24 matched output transistors and several other meaningful upgrades over my 565SE like a true balanced input stage and auto turn on options.
At 350 wpc, you’ll want to have some serious speakers to do it justice. Here’s a link if you want to get a better look. Over 80 lbs.https://www.theaudiolegacy.com/collections/amplifiers/products/adcom-gfa-575se
As mentioned earlier, I've been running in the 565SE, and as of now have about 25 hours on it. The new speakers have a little more, at 40 hours, so it's a little bit of an experiment trying to evaluate both at the same time.
The the way, if any are wondering about the validity of burning in new components, it certainly is a controversial topic and I don't mean to stir up anything, but I have found it beneficial in speakers.
As for amplifiers, my results have been more subtle. I've read that capacitors need to break in. In fact, they can view trace lines appear under the microscope of internal parts of caps. I can't find a link of that right now, but with 4 18,000 micro farad caps in this amp, it can't hurt.
I have heard improvements so far as the soundstage has become more real, and the speakers have begun to disappear as it were. Also vocals have become more transparent.
Anyway, maybe by next weekend I'll do some serious listening.
So I got a little frustrated with the Adcom amp, that I couldn't get it to heat up at all. The speakers are 4 to 8 ohms across the frequency range, with 4 drivers in a 3 way design. They are on the efficient side at around a 92 rating. I have to REALLY turn it up with these speakers to get the slightest warmth on the heat sinks. So I became a little inventive.
I decided to try connecting my 4 ohm bookshelf Totem Rainmakers in parallel with the Energy CF-70's. I believe the amp would see a load of about 3 ohms and under, depending on the Energy's. I cranked it up fairly loudly, peaks of about 90 db at my seating area, but left the basement for the room above where the Adcom set up was situated.
It was pretty loud! It become difficult to hear the TV unless it was cranked up somewhat. I ran it like that for about a 1/2 hr, then went down and checked on the amp. Well it definitely got warm, but only moderately so. I could feel the warmth coming off the heat sinks, but I'd say that the heat management is pretty effective, and the amp has a lot of capacity in that department. A 3 ohm load doesn't give it any trouble whatsoever.
I'm getting close to my 50 hour mark on the burn in, but I'm not fully confident whether that is enough. The Oddyssey amplifier company suggests that components take several hundred hours to fully break in. They also suggest leaving the amp on while it goes through the process.
I'm continuing with this little Adcom journal for any Adcom fans that may look for Adcom impressions in this forum. I know that I've done the "adcom" search here, and there is limited content to consider.
Also, I've made some after market improvements to my 565SE. I've treated all of the fuses(5 of them) with Stabilant 22. This is a substance that is a semi conductor until it comes into contact with electricity, then it becomes a super conductor. It improves any electrical contact point. 4 Fuses inside the case, and the one accessed on the back.
Then, I'm not using the stock power cable, but a PS Audio AC5 cable instead. It's a solid core, individually insulated copper conductor based design. Every component in my set up has cables of similar design, and so are my speaker and interconnect cables.
Speaking of speaker cables, mine(audioquest Rocket 44) are in a biwire configuration, so the little brass bars across the speaker terminals are not being used.
Each one of these items I've listed enhances or improves the end result. YMMV. BTW, I'm over the 50 hour mark, but am going to give it a little extra.
You suggested choosing wisely on the amp/speaker pairing above, and right you were. I returned the Energy cf-70 today. After 70+ hours on them, the mid range was just blah. No life, no energy, a veiled presentation. They had decent bass for the money, but it was like the life of the party was missing. When I swapped in an old pair of Infinity Primus 362, the magic was back.
So I wondered around the show room of the audio store today, listening to a few pairs of what the sales guy suggested. Nothing caught my ear until he turned on the Kef Q750 and 950. I thought the 950 added warmth to the vocals compared to the 750's, but really liked either one. I ordered a pair of the 750 in Walnut. They may have to come from either New Jersey or the UK, apparently.
So I'm occasionally swapping in different speakers on the amp, still running it in.
So to finish off my little saga, I’ve got about 80 hours on the big Adcom now. I’ve used little Tannoy DC4T speakers and the previously mentioned Infinity Primus 362, as well as the Energy CF-70, which I returned.
On the Infinitys, it’s a completely different presentation than the Energys. Nice and open at first, but discomfort after a while. I changed out my silver coated copper wire Morrow interconnects, and put a warmer speaker cable on them, Wireworld Oasis 7. After running that in for a couple of hours things smoothed out a lot. But as I’ve been changing speakers a lot as I experiment with the Adcom, they’re not the best to work with.
The Tannoys are different again. These ones are easy to please. I believe their impedance is pretty steady at 8, while the Infinitys vary a fair bit. The Tannoy also is much less sensitive at 88 vs 93 or so. The sound with the Adcom was much better to me. More balanced, more pleasing overall, and images just as well.
This morning I wanted to compare the 565SE to the 555MS, Adcom’s smallest amp in current production. So I installed the 555 and let it warm up for an hour. Interesting, it sounds better on the Infinitys than the 565, but of course with less dynamics that 250 wpc can do. Anyway, to compare detail, I used some Dianna Krall songs I know well. Then I put the 565SE back in.
With the same Dianna song, I could immediately hear that the piano was more accurate and real sounding. I wasn’t expecting that. A better soundstage as well, just a nicer presentation. It really is in another class.
So the 565 has more than just muscle to bring to the table. I would say the voicing is a little more foreward and open than the 555MS, and I could definitely hear this with the Infinitys, too much of a good thing. But on neutral speakers or onto warm, if that’s your preference, the 565SE can shine. One thing, I've got a little heavy metal music. With the Infinitys and the 565, the sound was a tour de force! I can't explain why...
I was experiencing good tight bass when I had the Energys playing loud, so the Adcom doesn’t lack there either. I can’t compare it to a mega bucks amp, but I really think its a price leader for the power rating. I think Emotiva’s XPA amps are around the same price, and the Oddyssey amps should be considered, although they are less power.
Here's just a footnote of sorts to my story.
I take back my findings on the Infinity Primus 362 or the Adcom 565SE being on the forward side. I really can't say for sure what the Adcom is, its kind of disappeared as it were. Above I had mentioned this, and that the Infinitys were difficult to work with.
I decided to leave them in the system as I wait for my Kefs to show up(apparently they may be coming from the UK, the Dealer wasn't sure at the time). Over time, the infinity speakers have warmed up, so to speak. No overly forward soundstage that gives me ear fatigue. No brightness or harshness. Not that they are warm sounding, but they seem to have really good detail in the mids and highs.
My preamp is the Schiit Audio Freya+, and I made another discovery. With the tubes engaged, and everything warmed up, real magic happens with those Infinitys. The Tweeter is better than I thought, and this SS amp/Tube pre combo is amazing at times.
One song stands out so far. The Gypsy Kings, Hotel California. The intro is magical, just magical. When the lead guitar makes his first full strum, the detail and exactness is better than I've ever heard it. Not too bad for some old cast off speakers that I picked up on Craigslist for cheap. I'm using silver wire IC's to the amp and source, and Wireworld Oasis 7 speaker cables, which are said to be warm.
what gear is currently in your system?
And I forgot to add one fact I found out about the Infinity Primus P362. It turns out the model is a 4 ohm speaker with an impedance curve that wanders under 8 ohms down to 4 ohms for much of the frequency range. But the placard on the back says 8 ohms, which is kind of a curve ball from Infinity.
on what my current gear is: Schiit Audio Freya+ preamp, Adcom 565SE amp, Schiit Gungnir Multibit dac, Nad C565BEE cdp. Cables by wireworld, Audioquest, morrow and Pangea.