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.




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.