Looking to upgrade Adcom GFA555: Parasound?

This is my third system.  Honestly, usually used for semi-active or background music.


Speakers are vintage Wilson Watt/Puppy 7.  Source is an Eversolo dac/streamer Into a vintage Classe DR5 preamp.  Amp currently is the aforementioned Adcom: bought it new while in college 40 years ago!  The sound is pretty good, though a bit “small” and closed in.  


Considering replacing the amp with a Parasound A21+.  Thoughts?  Am I wasting my time?

Target cost to upgrade this rig: less than $5K.




The THD on that Parasound amp is pretty high for what it costs. Not that it will sound bad but based on my distant past experience with Adcom and Parasound and all other things being equal the Adcom you have is going to sound brighter and more refined. Things may have changed but Parasound was geared more toward theater than hifi. I would recap the Adcom before I spent $ on a new one that may not meet your expectations. If you decide a new one buy, I’d buy from someone that will take it back with no restocking fee just to be safe.

I don't know what products he is involved with or if any have been released yet, but Darren Meyers (engineer) is now with Parasound. He used to be with PS Audio and I would buy anything he designs without a second thought!

I really like the Parasounds, but they can be overly warm, maybe too warm for a background system?  You know what you might really like if you dont need lots of volume is a Rogue or CJ integrated instead.

I'm not a fan of Parasound.

Have you considered having the Adcom rebuilt and upgraded? The two techs that I'm familiar with who upgrade the GFA-555 are John Hillig at Musical Concepts and Chris Hoppe at Hoppe's Brain. Both are well respected and get great reviews/feedback.

Might be nice to keep the Adcom for nostalgia's sake, especially if the upgrades offer significant improvements in sound quality.

I have the Parasound A21 and absolutely like what I am hearing. Your amplifier seems a bit older. Hence I feel the upgrade to Parasound will feel like quite a big upgrade, especially if you are going to drive the Wilson’s. You might be able to find a used A21+ in your budget.

Hello, I think a third system should be uncomplicated. I’m thinking a used Luxman integrated. You do not need a DAC because of the EverSolo. Plus, it can be used as a preamp, Amp, and an integrated amp. Plus, The phono stage is decent. I feel the Luxman line will provide you with the same sound but with better detail. If you have a chance to hear it or borrow one I really recommend it for you. I just believe the Parasound is like a nice Amazon Alexa. If you want that sound save yourself a lot of money and buy a few to spread around. 

I’d demo the Parasound or something else. For me, at least, the Adcom has always sounded tonally threadbare.

I'd highly recommend the guys at Musical Concepts, John Hillig has several options for that unit and can even provide new FETS from Exicon that really give that amp significant improvements in the sound quality.

I second or third the idea of keeping the Adcom.

I recently reached out to Chris Hoppe to refurb my 565’s and he put me in touch with Jon Morris. Jon did a great job overhauling my mono blocks using Chris’s new designed cards and all of the best components.

altonbtc@gmail.com Is Jon’s email address.

Much cheaper than the alternatives. And should sound as good or better.

Why not a Classe CA-300/400. Can you ever over power a Wilson Audio loudspeaker?

I recently received the Magnepan LRS+ for my bedroom/home theater 2.1 system.

I assumed I would have to get a new amp for this system but discovered that my old Adcom 545 II drove the LRS+ so well that I don’t know what else I would want in an amp in this context.


@reubent ..."The two techs that I’m familiar with who upgrade the GFA-555 are John Hillig at Musical Concepts and Chris Hoppe at Hoppe’s Brain. Both are well respected and get great reviews/feedback. ..."


OP @bobbydd +1 to @reubent’s posts above. Definitely worth serious consideration. Also worth identifying if yours is a MKI or MKII original GFA-555. In any case, these type of techs know what to replace for aging and upgrades where it matters.

I took a chance on investing and fully upgrading one of Nelson’s other designs on the Pass/Forte amp side, not exact - but some of the same lineage. Give those folks a call listed above and ask them more about what they replace, upgrade, and the expected differences and outcome. You might be surprised. Super happy with mine, and really like how it sounds.


I have a Parasound JC5, new it’s a little more expensive than the A21+, but really close in watts per channel at 300 for the A21+ and 400 for the JC5. You can get a JC5 used between $4-$5K. I had may choice narrowed down between the Adcom 585SE, JC5 and the A21+. I don’t think you can go wrong with any of these. I’d think the A21+ is an upgrade to your Adcom GFA-555. I love my JC5, has a warm sound in the mids, highs are not bright, great control over the bass. If it’s budget to stay under $5K and you want new, get the Adcom 585SE though, it’s comparable to the Parasound JC5 at 400 a ch. I choose the JC5 because it has some class A functionality on the low settings then switches to class A/B, but I can’t hear the transition of course.

Been years since I’ve listened to a GFA 555, and I’ve heard them with the Musical Concepts mods as years past the local Adcom dealer also carried Musical Design. That dealership is still in business and carries Parasound which personally I have not dragged one home, but in the store I have enjoyed them. I’d probably lean to the A21+ with your WP 7’s with the Focal titanium tweeter. I have WP 6’s and with my PASS X250 they sound wonderful together. The Parasound will probably be a great match with the older Wilson’s. Just remembered, the dealer I’m talking about used to carry Class’e too.