Amplifier chassis adapters

These parts were useful when I built Rob Robinette's JCM800 Micro EF80 amplifier in a Princeton Reverb amp chassis. There were extra socket and cap can holes that needed to be covered, and I wanted to mount the EF80 output tubes into the output tube socket holes.

Octal or 8 pin tube sockets are typically used for output tubes (6V6, EL34, 6L6, KT66, 5881) and some rectifier tubes (5Y3, GZ34).

Noval or 9 pin tube sockets are used for preamp tubes (12AX7, ECC83, 12AT7, ECC81, ECC82, EF86), output tubes (EL84, EF80), and rectifier tubes (EZ81, 6CA4, 6X4).

Print these using ABS and PETG (not PLA) to better handle the heat generated by the tubes.

Hoffman board mount drilling template

I ordered a turret board from Doug Hoffman, and printed a drilling template for the mounting screws. All the Hoffman boards are 3.5" wide, but aren't drilled for the mounts.

Octal socket blank

Used to cover an octal (8 pin) tube socket hole. Screw spacing is 1.5".

Noval socket blank

Used to cover a noval (9 pin) tube socket hole. Screw spacing is 1.125".

Octal to noval tube socket adapter

Adapter plate for mounting a noval tube socket into an octal tube socket hole. Adapter ataches using the 1.5" spaced holes in the chassis. The noval socket mounts on the plate using the 1.125" spaced holes.

Cap can grommet blank

If your amp doesn't use large can capacitors, use the hole as a grommet/wireway for wires from your power transformer, output transformer, or choke. For 1.5" diameter cap can holes.

Octal socket grommet blank

If your amp has an unused octal tube socket holes, use it as a grommet/wireway for wires from your power transformer, output transformer, or choke.

Antek torroidal PT mounting plate

Antek torroidal power transformers mount using a single bolt and small hole. Most amp chassis have a rectangular hole for the power transformer. This mounting plate fits into the rectangular opening with a central hole for the torroidal transformer.