The Brand New Adcom 555SE and 585SE Sound Great

I have the Adcom 5500 amp. Bought it a few years ago.

 

Agitater: Thanks for the heads up on the Adcom! I’ve been considering going to separates with an amp in the 200wpc range and was not aware of Adcom being a current supplier. I appreciated the in-depth review and will investigate further!

 

I purchased an original 555 back in 1985. That was the first really great sounding amp I ever owned. I wonder how different this new design is supposed to be compared to its namesake?

 

I have no reliable memory of the originals. But if consensus opinion about the originals is anything to go by, the few rough edges, the lack of sophisitication in some frequency ranges, and laboring at certain volumes with complex recordings that all cropped up from time when listening to speakers amp’d by the original Adcoms is completely gone in favor of high quality across the range. Also, the 555SE is very fast. I have to be careful here because I’m getting into effusive reviewer territory when I don’t mean to do that. I think the 555SE is well worth an audition. Only your own hearing knows for sure.

That said, you raised a very interesting point. I’d love to compare a refreshed Adcom amp from 1985 side by side with the newer 555SE. That would definitvely tell the tale.

 

Well considering the 555II could be had new discounted for a paltry $660 in 1992 I don't think there's a fair playing filed with an $1,800 new version. I don't think 20 years inflation more than doubles the cost.

 

Compounding inflation, taking into account recessions and everything too, certainly does double the cost of some goods over 25 years - easily. Check your arithmetic. 1992-2017 is 25 years. Anyway, hard goods of all kinds have doubled over 25 years. Some things - motor vehicles for example - have only risen 50% or so, but the manufacturers make millions of cars every year while makers of stereo amps in this class only make thousands of amps. The differing economies of scale have very different effects, over time, at retail. Anyway, you were comparing US$660 to CAN$1800.

Then again, I think complaining about prices only from the standpoint of what a particular person wants to pay, or what he somehow thinks things should be, and without the slightest perspective on what it actually costs to design, develop, provision, manufacture, distribute, advertise, merchandise, support and sell a particular product, is a vague complaint that needs a lot more backup before it deserves any merit. If I’m wrong about that, then I apologize.

 

I am still running an original 535L with some mods. 1989. The thing is bulletproof and has lasted through 3 other amps that died eventually (2 NAD's and 1 Yamaha). It is a little under powered but still drives my 4 ohm, 82db sensitive Mirage M7si's just dandy. Definitely looking at the new 555.

 

Man, you are tough and aptly named!

Since accuracy seems to count around here, US$600 in 1992 dollars equates to US$1041 in 2016 dollars adjusting for inflation. CAN$1800 equates to US$1417 per current currency conversion rates. Therefore, as it pertains to the amplifiers in question, inflation has not more than doubled the cost.

You wrote up a compelling testimonial that was balanced and informative about an amplifier that I tried to tactfully point out was actually new in 2009. GuildX700, whom I do not know, simply pointed out that a comparison of old and new Adcom amplifiers of similar heritage may not be a fair fight. I did not see a complaint in his comments as you did, nor did his statement give rise to any ignorance about manufacturing expenses on his part. Reading through his statement, my take away is that since inflation did not double the cost, yet the 555SE costs $1800 (CAN), there must be some advances in materials or manufacture that make the 555SE a superior unit. You say his statement is meritless. I say he was complementing your taste.

 

The Original was a great sounding amp. It only had a few issues that I can think of: No circuit protection, No Muting, and No output choke. All of this was done deliberately for sonic reasons in an attempt to have the best performance humanly possible.

The lack of an output choke occasionally caused some instability when running very capacitive cables with some speakers. This could lead to ultrasonic oscillation of the amp. And the lack of any protection meant that it had the potential to fry a speaker, if an output transistor shorted.

Sonically its only real Sonic weakness was that its soundstage, though gigantic, sounded 2-D when compared with a good tube amp. But that is true of almost all SS amps. Other than that, it was one hell of an amp for the money when it was introduced.

I know that Adcom slipstreamed a few minor design changes over the years to try to make the 555 more stable, but IMO these caused the later models to lose some of the magic of the original design.

 

Used to own a GFA545 back in the day, bought it with a GFP555 preamp. Was a pretty sweet combo!

 

I don't recommend ADCOM. I bought a GFA-565se and a GFP-815 preamp in April '17 and out of the box with no input I hear harmonic noise out of my speaker. When no music is playing you'll hear a low hum from the speakers, wtf. I live on the west coast and the dealer had me send it to NJ for repair. I waited months for parts from Thailand. Finally came back in late Nov and no change. Took it to a local electronics shop and they measured the noise and gave me the service report. When I called the NJ service site with the service report I was told there's nothing wrong with the unit. I was told I have to ship the units back to NJ if I want a refund although I purchased from from distributor in Phoenix. When I asked the local electronics shop who is listed on the ADCOM site to repair they told me there are no available parts to repair the 565.

This company may have had good products in the past, but I'd stay clear. Their equipment is substandard, their service is a nightmare and evidently no parts to serivce

 

Why did they not exchange for a new one?

 

My 5500 amp is in for service. No bass. Might be looking for another amp to go with my Theos speakers.

 

By your description, it sounds like you are describing a ground loop. I had this same problem when I bought a new piece of gear this past year. Turned out to be the fact that it and another component were plugged into the same surge unit and didn't play along well with one another. Changed the outlet one of the units was plugged into and BAM! No more hum coming from the speakers.

Good info on identifying and correcting this problem:

SYSTEM NOISE | Galen Carol Audio | Galen Carol Audio

 

Has this changed for the new 555SE, at least the circuit protection? And is it true balanced? Amazon user review says its single ended XLR.

 

If you go to the actual product page on the actual Adcom web site, you'll find that there are two sets of inputs: unbalanced RCA, and XLR connections that can be switched into balanced or unbalanced mode. Go here:

ADCOM High performance audio amplifiers, pre-amplifiers and tuners

Reads the specs. Look at the product photos. Note the rear toggle switches for balanced/unbalanced mode.

 

Sorry, I have no idea about this newer version. But if this has all changed, then it probably would not have much resemblance to the original 555 except in name. I seem to recall Adcom claiming that the lack of circuit protection, and the lack of an output choke were contributing factors as to why the original 555 to sounded as great as it did.

 

I too owned an original 555 amp back in the day. Great sound for the $. I'm glad to see they are back in business with new gear. Thanks for posting this info.

 

Of course, I always check a manual first. But there is this amazon review stating the following:"...BTW, the 555SE's XLR's are just single ended, so not true balanced, but still sound good..."
What's that supposed to mean?
There's also no word on the protection. Do you know something about these things?

 

I’m using a 555 II with my L100 Classics and feel no need to change anything. I’m glad they’re making new ones though.

 

What is it supposed to mean? Nothing important. It’s just some Amazon customer babble. It doesn’t mean anything because it flies in the face of the facts that are plainly evident to anyone who chooses to go to the product web site and look at the actual photos and specs of the amp. I suggest not reading reviews on Amazon as though they’re authoritative.

All modern amps have power supply, input and output protection, including the 555SE. Click the product link I provided, read the marketing literature, read the specs, then read the product manual (PDF link on the product page).

 

I wonder if stereophile or The absolute sound reviewed this?

 

Did you read the very first post in this thread? If not, it may help.

 

Thanks for the review, @Agitater, and for running this thread. It's nice to see someone try to maintain order and focus in the thread they started.

In the old, steam-powered stereo days, I was more of a 545 fan, thinking that's where Adcom hit their sweet spot. I'd love to audition the new 555, though. I bet it would make a dynamite subwoofer amp. I've thought more than once about reviving my skills in designing and building sub boxes for cars and making a dual 10" sub for my living room. Loud, bitchin' car stereos were one of the best things in an otherwise dismal decade, the 1990s, and my stereo store sold more than our share.

 

If my 555 II fails, I’ll probably just keep buying used ones for $400 until they all crap out.