Photos Phillips roll reader is use

The new reader was commissioned late 2011, set up to record Duo-Art rolls. My 1925 pedal-electric Duo-Art reproducing piano was fitted with the Hunt Virtual valve system and could therefore act as a monitor when recording Duo-Art rolls.

Duo-Art recording setup. The roll reader sits on a tailor-made wheeled cabinet that holds the suction pump, power supplies and MIDI electronics. The computer sits on an adjustable-height shelf that is attached to the door of the cabinet, and when lowered, it and the computer slide into the cabinet when the door is closed. Over 2300 Duo-Art rolls were recorded with this arrangement.

Welte-Mignon recording setup. Welte-Mignon rolls are unique in size, so the standard size spool box built for the roll reader could not be used to record these rolls. Instead, a spool box from a late model, upright Welte-Mignon was found and adapted to fit the roll reader, now without its spool box. An electric motor was fitted in lieu of the traditional air motor, and separate play and reroll speeds were designed into the electronics. As tempo is critical, this was monitored by a period counter displaying the time taken per revolution of the motor drive shaft.

Ampico recording setup. The 1923 Ampico A shown above was the monitoring instrument when recording Ampico rolls. An in-line Ampico expression decoder now allows Ampico rolls to be monitored on the Disklavier.

Decoding Welte expression. Monitoring each recording was done on a Disklavier Pro. This required the expression coding on the rolls to be converted to MIDI velocity values, and the pedal information to MIDI controller data. This was initially done by the analogue electronic circuitry sitting next to the roll reader. The oscilloscope shows the expression level.

This microprocessor-based unit is now used to decode the expression on all types of Welte rolls to MIDI data. The software was developed using data developed from the original analogue decoding system.