Gear Info



Grampian Ambiophonic Unit – Type 666

In addition to all our Grampian 636 information, we also picked some info about the Grampian ‘Ambiophonic’ Unit, Type 666. An interesting (and very rare) piece of 60s gear: a version of the famous Type 636 designed to use the reverb “to alter apparent room acoustics” in auditoria.

We’ve been fortunate enough to have one of these (pictured above and below) come through our hands; essentially what you have is a broadcast-quality, very clean-sounding Grampian Type 636. So it won’t produce the famous overdriven distortion, but produces a great, rich reverb effect that is good with pretty much anything. Very uncommon, these were apparently built for the BBC and used by BBC Radiophonic Workshop.

Below are links to the documentation we were given – you can view and download from the links below. Note that these were given to us to distribute and are free to use, however if you use, re-post or share them then please add a credit and a back link.

Original Grampian Ambiophonic brochure & technical spec

Schematic: Grampian Ambiophonic Unit Type 666


This page is part of our collection of resources on the legendary Grampian Type 636. Read more about this remarkable unit and see all the information we have gathered over the years here. We’re fanatical about these units and sound they can produce if restored to full functioning – if you are looking for one of these units, or have one to sell in any condition, please get in touch.

More Grampian Goodness

Resources & info from around our site:


Grampian Reverberation Unit Type 636

A growing collection of information about the Grampian 636: history, schematics, manuals, sound & video clips; plus our Soundgas Type 636 project to recreate this iconic...


Grampian 636 Instructions & Schematics

Directory of original Grampian documentation we have, including tech specs, schematics and articles, to view and download.


Grampian Type 636 Operating Instructions

Grampian Type 636 Operating Instructions & Technical Specification reproduced into a searchable format.


Grampian User Tips

Some useful info for using a Grampian 636 in a modern studio set up. By no means a full user guide, but this should help you...


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