Adcom?

About 98 was when Adcom started having Chinese production, and back then there were issues with Chinese manufacturing.

To the OP, you mention your experience, but not the time frame.  The 5300 was built from about 97 to 2006 or so.  I had one from 2001, and later bought a 710 around 2008.  I had the exact same problem when I added the 710, it had nothing to do with the amp.  (I remain unclear on whether "marking" the frames would show whether the units had been opened up.)

The volume would ramp up by itself to full volume, and the distortion lights on the 5300 would go crazy until I got over there to turn it down.  I had the 710 replaced, but the replacement did the same thing.  I got my money back and later heard the 710's remote sensor was affected by the noise that a cfl light bulb emits.  I have no idea if it's true.

The new Adcom amps really do look interesting though and they've always put out a decent amp.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.