1966-68 Vox JMI Cast Iron 2-Button Footswitch M/T - MRB Momentary + Tremolo Latching - Silver Hammerite Serif VOX - TRS - Berkeley II / Conqueror

Vintage 1966-68 Vox JMI / Vox Sound Equipment Ltd 2-Button Cast Footswitch - M = MRB, T = Tremolo

Original heavy cast iron housing with tough silver hammerite finish. Embossed serif VOX logo, M and T in circles. This is the rare MRB/Trem version from the Conqueror / Supreme / Berkeley family, not the common Reverb/Trem.

This pedal controlled reverb, tremolo and MRB (mid range boost). The factory used the same casting for D=Distortion, R=Reverb, V=Vibrato versions.

Features:

• Body: cast iron coated with a tough silver hammerite finish — serif VOX mould
• Buttons: 2x pushbutton — M is momentary, T is latching — factory correct for MRB
• The MRB foot switch is unique in that it does not have a latching mechanism. It is a "momentary" style switch. One must hold the button down to engage the effect
• Cable: original hardwired 10ft approx vinyl jacket, 1/4" TRS stereo plug
• Base: shaped metal plate with ridged rubber, single central screw (2BA/4BA)

Function / Wiring Notes for Tech Buyer:

• This is a passive grounding switch — no battery, no LED. The amp provides the voltage and the footswitch shorts to ground.
• TRS wiring:
• • Sleeve = common ground
  • Tip = M - MRB - momentary to ground - closes only while held - Pin 4: To momentary switch to ground for MRB
  • Ring = T - Tremolo - SPST latching to ground - Pin 1: To Tremolo switch to ground - click on / click off
• Switch type: An exact replacement for the tremolo and reverb switch mechanisms Thomas two, three and four button pedals. Also suitable to replace the reverb and tremolo switches in JMI and VSL three button foot pedals. It also can be used in the MRB circuit. Latching = SPST latching, Momentary = SPST momentary.
• Test with DMM: T latched = ring to sleeve 0 ohm, unlatched = open. M held = tip to sleeve 0 ohm, released = open.

Compatibility:

• Berkeley II V1081 / Berkeley III V1084 - MRB + Trem - The US Vox V1081 and 1084 solid state Berkeley II and Berkeley III included this accessory three button foot pedal. This pedal controlled reverb, tremolo and MRB
• Conqueror, Defiant, Supreme, Virtuoso when configured for 2-button MRB/Trem
• Cambridge Reverb II V1032
• AC30 Super Reverb Twin / AC15 Twin Reverb if configured for MRB + Trem - also works as Reverb + Trem if you swap labels — circuit is identical, just grounding
• Will also switch reverb/trem on modern AC15C1, AC30C2, AC15VR, AC30VR via VFS2A jack — but collectible value is as vintage JMI

Condition:

Good vintage condition. Original hammerite with light edge wear and patina as photographed. Logo crisp. Cable and TRS plug original, no cuts. One silver metal cap, one black plastic cap — indicates one switch was serviced at some point with later Vox enclosed switch — functions correctly now. Latching action positive on T, momentary return positive on M. Base rubber intact.

Sold as-is, as tested with meter — no amp test available. No returns on vintage electrical.

Includes: Footswitch only, as pictured.

From private collection, Alpine, UT. Packed well.