ADCOM GFA-555 MK2 boards are here!

Hi everyone,
My GFA-555 MK2 boards are ready to go! Thanks to Jon Morris of Morris Audio in Wyoming for helping me work out the bugs and validate the design. He’s already restored a few customer’s GFA-555 MK2’s with my boards.

Get one here in my store. – GFA-555 MK2 Input Board

NEW – I am now offering these boards fully assembled and tested for $380. All you need to do is make sure your power supply and output section are good.

GFA-555 MK1 “VERTICAL” boards coming soon!

Do you have one of the first batch of ADCOM GFA-555 amps ever made? My GFA-555 MK1 boards work great in these amps, but they must be physically modified to work with the horizontal board.

Until now! I have designed new boards for these early “Vertical” 555’s.

I really like how this layout turned out. Very pleasing symmetry.

This is the original board:

Continue reading GFA-555 MK1 “VERTICAL” boards coming soon!

The nicest GFA-555 MK1 I’ve ever built, $1600

Update: *SOLD*

Dang, I kinda want to keep this one, but here it is for sale!
Hoppe’s Brain Refurbished ADCOM GFA-555 MK1
This particular GFA-555 came to me as a customer trade-in, and was very well loved and cared for, so I thought it deserved a new life.

I went all-out on this one. It’s got all the options, including an entirely new input circuit board, and a soft-start power supply with (4) 27,000uF capacitors.

Continue reading The nicest GFA-555 MK1 I’ve ever built, $1600

Because I’m terrible at self-promotion, here’s a video I should have posted last month!

YouTube blogger XRayTonyB did a three-part video series on repairing a GFA-585 using my boards!

As usual, he goes into great detail on the restoration process, and gives all kinds of generally helpful electronics troubleshooting advice along the way. Tony’s channel is loaded with videos about restoring some really interesting gear like vintage receivers, amplifiers, test gear, etc.

This was not a paid promotion, and there is no commercial affiliation. Tony just bought boards from me like any other customer.

A Tour of a Hoppe’s Brain Adcom GFA-585 Restoration

Hi everyone,

This is perhaps the nicest amplifier I’ve ever restored! A GFA-585; The first of its kind with newly designed replacement input boards. (To fix the infamous leaking capacitor issue.) And I can’t believe I’m saying this, but…

It’s for sale. $1800. Update: SOLD to previous customer, Bill.

Also, I wanted to share what I know about restoring a GFA-585. I hope this is useful to others who are tweaking their GFA-585’s, or installing a set of my replacement circuit boards.


Continue reading A Tour of a Hoppe’s Brain Adcom GFA-585 Restoration

New, improved GFA-565 circuit boards! Now available fully assembled and tested.

Hi everyone,

Long time, no blog! I’ve been super busy with Adcom amp and preamp refurbishings, and obsessing over new circuit board designs.

Here are completely new versions of the GFA-565 input boards, and for the first time, I am offering fully assembled and tested boards for $380. (Please allow up to a 15-day lead time. They are hand-made, by me in my shop.) Click here to buy.

Continue reading New, improved GFA-565 circuit boards! Now available fully assembled and tested.