By popular demand, I have created new input circuit boards for the GFA-555 MK1! These boards integrate all of the improvements I normally make when I refurbish a GFA-555.

Buy one here.

Continue reading New Adcom GFA-555 MK1 Input boards!

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.

I’ve just finished building this batch of GFA-565 input boards. More are on the way soon!

Buy ’em here.

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

Hi Everyone,

At last, GFA-585 input boards! Available at my store.

GFA-585 input circuit board left

GFA-585 input circuit board right

As you may know, the Adcom GFA-585 suffered from the same leaky capacitor issue as the GFA-565.

Continue reading Adcom GFA-585 replacement circuit boards are here!

Hi Everyone, my store is finally online!

Hoppe’s Brain Shoppe

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I have just three products up there right now, but there are more to come.

• GFA-555 Soft-Start Power Supply
• Universal Amplifier Soft-Start Power Supply
• GFA-565 replacement circuit board

Coming soon: (These items are all available by request, just not yet in the store.)

• GFA-535 MK1 Power Supply board
• GFA-535 MK2 Power Supply board
• GFA-545 MK1/MK2 Power Supply board
• Unbalanced stereo line driver. One stereo input, four stereo outputs, buffered and driven by OPA2134 op-amps. (For running long unbalanced patch cords, or adding buffered tape outputs to a preamp, among other uses.)
• Bipolar audio power supply, +/-15V. Super low noise, low impedance and high speed. Based on TI LP38798.

Thanks to all my customers for the continued success of Hoppe’s Brain. I am so happy to be doing this for a living.

Hi Everyone,

Hoppe’s Brain is thriving, but demand for my services has been overwhelming! My waiting list has grown to more than a year, so I’m sorry, but I must declare a temporary hiatus on accepting new clients for repairs and refurbishings.

I need concentrate on my existing customers. Thanks for understanding.

I still sell circuit boards and kits, and this area of Hoppe’s Brain will continue to expand. Look for my store to go online in the next few weeks. In the meantime, contact me with the form below and let me know what you want. (Power supply boards for GFA-535, 545 and GFA-555 amplifiers, GFA-565 input boards, etc.)

If you’ve emailed me and not heard back, I will get back to you within the next few weeks.

Thanks to my awesome customers for making Hoppe’s Brain a success!

Chris

Hey there people! Here’s a sneak preview of some new circuit boards that just arrived, in preparation for my web store grand opening. All but two of the boards shown will be available for purchase by DIY’ers. (Along with existing boards like the GFA-555 soft-start power supply and GFA-565 input boards.)

They are:

Continue reading Boards, boards, boards!