Binding Post Adapter Kit


Binding Post Adapter Kit for standard 3/4″ spacing. Fits Adcom GFA-535 MKII, GFA-545 MKI, GFA-545 MKII, GFA-555 MKI, GFA-555 MKII, GFA-565, GFA-585 and many others.



*Feb 3, 2023 – Sorry, versions of this product that include a set of binding posts are out of stock until March 20 at the latest. (I ran out of binding posts, oops, they are on order.) You can still buy the plates and install your own binding posts.

The Problem:

You want to replace the binding posts in your amplifier, but the holes in the chassis are too large for most binding posts on the market, which are designed to fit chassis cut-outs of 10mm or 11.5mm in diameter.

The Solution:

Hoppe’s Brain Binding Post Adapter Plates.

Two fiberglass plates sandwich the sheet metal, and the binding posts fit into the plates, which are firmly attached with four M3 screws and locknuts. Simple, secure, and easy to install and service.


The adapter is designed to fit standard 3/4″ spacing chassis cut-outs. The plates come in two mounting hole sizes, 10mm or 11.5mm. The 10mm type is compatible with the optionally included binding posts, and many other brands. The 11.5mm type fits WBT, Parts Express and others. Refer to manufacturer’s drawings to determine if they will fit your choice of binding posts. The binding post’s diameter must not exceed 3/4″, or 19.05mm, or they will interfere.

Refer to these drawings to make sure things will fit in your amplifier. They are made of 1.6mm thick FR4 Fiberglass. Please don’t steal my design for profit. I am publishing full dimensions so my customers can make sure things fit.

Kit contains:

  • (4) Fiberglass adapter plates, 10mm or 11.5mm
  • Optionally, (4) Gold-plated brass, insulated binding posts, as shown.
  • (8) M3 Button-head screws
  • (8) M3 Lock-nuts

Tools required:

  • 12mm Hex nut driver or socket
  • 5.5mm Hex nut driver or socket
  • 2mm Hex driver or hex key
  • POWERFUL soldering iron with a large chisel tip. 70W regulated or better. The binding posts have a lot of brass that soaks up heat.

Installation documentation here.

Additional information

Weight N/A
Dimensions N/A

Full kit with Gold-plated Brass Binding Posts, 10mm Plates and Hardware Only, 11.5mm Plates and Hardware Only

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