Traditional relay

The relays originally provided by the theatre organ builders were very complex pieces of equipment. There are many parallels with early telephone engineering and it is not surprising that Robert Hope-Jones, one of the early theatre organ pioneers, came from this background.

The essential inputs are from the stopkeys (which stops are ‘on’) and from the keys (which notes are being played); the outputs going to the magnets in the windchests in order to make the pipes play.

Relays fall into two categories, Stop-switch relays (favoured by Wurlitzers and Christies) and Matrix relays (favoured by Comptons).


See further:

Matrix relay

Stop switch relay