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Brand New Adcom Amp - In the house!

runnin'

runnin'

Super Member
IMG_9331.jpg IMG_9329.jpg I thought I'd share this in the New Gear Values because it's a pretty great bang for buck amp. The GFA 565SE:

250 wpc, 350 into 4 ohms

Frequency Range -3 db is 5 hz to 100kHz

Damping factor 800

THD is under .009%

I’ve got about 80 hours on the big Adcom now. I’ve used Tannoy DC4T, Infinity Primus 362, as well as the Energy CF-70 speakers while I broke it in. At one point I also connected some 4 ohm speakers in parallel to the Energy to see how much it took to warm the amp up because it mostly ran cool with any of these speakers.

The Energys were somewhat warm sounding, and with a boring mid range. I tried several different things and being that I just bought them, was able to return them. On the Infinitys, it was a completely different presentation. 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 fair bit. 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 were different again, 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 imaged just as well.

So after two weeks of that, I wanted to compare the 565SE to the 555MS, Adcom’s smallest amp in current production(which I also have). So I installed the 555 and let it warm up for an hour. Interestingly, it sounded 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. It sounds effortless and open and added dynamic impact to drum or bass notes.

So the 565 has more than just muscle to bring to the table. I would say the voicing is a little more forward 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. If you are looking for some more power in an amp, Adcom is still a worthy addition to the short list.

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It's nice to know how the SE series compares with the old stuff, I've tinkered with the idea of getting a classic Adcom, but decided to go new as I didn't want to deal with the old caps and such. The manual on the 565SE says it takes over 5 minutes for the amp's caps to fully discharge after turn off, and the power light stays on for 33 seconds after you turn it off like it wants to keep rocking!
 
Just be careful with these amps!

They can pass large amounts of current should you do something upstream that causes something untoward...like, always shut off the amp before moving any cables around, a momentary burst of static, ground loop, etc., will come through the amp at full tilt boogie and wipe out speaker drivers, I did this on my previous Martin Logan Aerius-is, on a set of Lowthers, a set of Totem Hawk woofers, a set of Triangle woofer and midrange...you get the point, be very, very careful with these amplifiers. The 555II is what took out the Aerius-i woofers, a 535 took out the Lowthers, everything else was done with the 555SE and me f-ing up.
 
An audio dealer I use from time to time used to carry Adcom. When I was in his store I noticed the banner was missing for Adcom. He said he dropped the line because he was getting returns due to constant failures. It got too costly for him.
 
And how far back was that? It was in I think 2013 that the new line came out, the Special Edition line. Believe it or not, I've purchased 4 from their current line up, including one used. No issues yet. That said, I could understand an Adcom dealer dropping the line with the old designs. Back in the late 90's Adcom made the fateful decision to have their amps made in China. Lots of failures from those amps, however.

Also, people that have new amps break down are very prone to going online and complaining about it. I can't remember any complaints from the current, in production Adcom amps, and I've read most of the forum posts across the net. Lots of posts about older Adcom amps with the failing caps and lack of speaker protection, but the new amps don't have issues with either of those problems.
 
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Anyway, I was in communication with both the Adcom distributor for the west coast and the retail place that I bought the amp from, both knew how to treat the customer, they were great to deal with.

At this point the amp has almost 100 hours on it and is sounding like it should cost a lot more, it’s pretty impressive. I’d been using small speakers for the last year and forgot how impactful big towers can sound.

It’s a treat to have 250 watts per speaker. My Vidar is good for what it is, but 100 wpc can not compare imho.
 
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Very cool! I had a GFA555 in my system for probably 20 years and never had a problem with it. I like that they're keeping up with the times and putting XLRs on the back now.
:thumbsup:
 
So last night I observed something with the sound changing. The Infinity speakers had been consistently forward and somewhat bright sounding. I'd put them in the system, take them out, connect them in parallel with other speakers, and they were pretty consistent. But for the last few days they've been the only speakers in the set up, and I noticed last night that they are no longer bright, or at least significantly less so.

I should say that they've been in storage mostly for the last year until about 2 weeks ago, and I've now made them the main speakers because they can handle the 250 watts best of all my current speakers(until the Kefs get here). They are rated for 200 watts. Anyway, I suddenly noticed this when I realized that I wasn't getting ear fatigue, and i started to listen closer. The sound didn't have that glare, the occasional harshness, none of it. I was quite surprised. I also realized that the tweeter on these speakers, the Infinity Primus 362, is kind of the weak point of the speakers. So speakers, or at least some of them, do need time to adjust when they've been in storage for a while.

I don't subscribe to the theory that something like this is simply our ears getting used to the new sound. But it could be the amp continuing to break in, although at the 90+ hour mark, I really think it's well past any large changes. The Adcom really is sounding nice, btw, a very live sounding soundstage.

I also noticed that the bass drivers in the Infinitys were not moving much with bass heavy sounds, although I suppose the bass response was volume appropriate(I prefer to keep volume levels below 90 db, it gets uncomfortable). But it just so happens that I have an EQ, a 4 band Schiit Audio Loki. It's bass band is apparently 20 hz and goes + or - 12 db. Here's how Schiit Audio describes it:

Technically, Loki is a single-gain-stage active EQ with non-constant-Q passive filtering. In more English-y terms, that means that each band varies from broad to narrower as its gain is increased—small turns of the knobs result in broad, shallow changes, and bigger turns result in more narrow-band changes.

So I cranked the bass up 12 db, picked a song with strong bass presence, and slowly brought up the volume. Yep, the Adcom got those 6 1/2 drivers moving, and the amp still didn't get hot at all. I thought I better be cautious, so I didn't push it past about 1/4" movement. It did pressurize the room pretty well, but I only tried a few songs, then took the EQ out of the loop, as I intend to use it in the headphone set up.

And really, I have yet to find a weakness in the Adcom.
 
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RickB said:
I can attest to the fact that my 555SE is a different and much better sounding amp than my 555II.
Click to expand...
Just saw this and it reminded me that I've never heard the original 555 or 555II. But I can say that the 565SE has more refinement over the 555MS, which is also a current model.

Also when I opened up the 565SE I treated the fuses with Stabilant 22, which improves the connection point. It'a a product that was apparently used by NASA.
 
I have a GFA5500 from about 25 years ago . Never a problem . When the amp is turned off , does it still discharge thru the speakers with a thump ?
 
No, the current Adcom amps don't do that, perhaps because of the speaker protection relays, or how they operate in the circuit. I had a GFA5300 that I bought in about 2002, and it would thump through the speakers when turned off, but the new amps don't do that anymore.
 
Great to read the opinions and experiences of someone who owns and has spent quality time with Adcom's new amps. I've owned/still own many pieces of Adcom gear, and have been wondering how the new gear stacks up against their classics from the 80's/90's. Thanks for posting.
 
Hey Tedrick, I can't help but notice that you've had some Infinity speakers. Have you ever driven them with Adcom amps? With my tube pre amp and Adcom 565SE, I'm pretty impressed.
 
runnin' said:
Hey Tedrick, I can't help but notice that you've had some Infinity speakers. Have you ever driven them with Adcom amps? With my tube pre amp and Adcom 565SE, I'm pretty impressed.
Click to expand...
Indeed I have. I used an Adcom GFA-555 Mk II for many years with RS-IIIb's and later RS-IIb's. Even with the more-difficult-to-drive IIb's, the '555 rarely got hot, never clipped, and always sounded great. I also had a chance to audition a friend's GFA-5802 on the IIb's; that was an excellent combination.
 
I will be up front in disclosing that I am a big fan of the original Adcom amps being the owner of a pair of meticulously restored/upgraded (@Mayank ) 555's and 565's as well as a pair of untouched 535's. They were well regarded in their day and assuming that this latest version is based on the original design and are well built then the OP has an amp that they can be happy with for years to come. Congratulations!!
 
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Thanks Wolverine, you can tell that the old 555 line up is highly regarded by the prices they still sell for today.

And thanks for the info on your Infinitys, Tedrick, it mirrors what I’ve been experiencing. The P362 really excel with rock and rock guitar. There is a little bit of grit to electric guitars and such that really sounds better than other speakers I’ve compared to.

It reminds me of my Grado SR125E headphones, which is why they are one of my favorites.
 
So I swapped in the Schiit Vidar for the Adcom. I had to change RCA cables for the Vidar(I had all solid core silver stagers on the Adcom) to Wireworld Oasis 7( all copper). The Vidar sounded better, and there was a lack of smearing in the highs that I hadn't noticed the adcom doing.

So after a couple of days, in went the Adcom 565SE again, this time with all copper RCA's. This time the highs were fine, and the Adcom sounded just a touch warmer. Strange. Both amps are great sounding now with very little difference.
 
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