| Digest Nr | Subject and Author |
|---|
 |
| 2023.05.28.01 | Seek Hupfeld Helios Rolls or MIDI Files, from Ron Schmuck |
| 2012.03.15.06 | FS: Hupfeld Helios, Triphonola & Welte Organ Rolls, from Klaus Peuler |
| 2010.10.25.04 | Seek Hupfeld Helios Rolls, from Dave Bowers |
| 2010.07.30.05 | FS: Hupfeld Helios & Welte Cottage Rolls, from Klaus Peuler |
| 2010.01.08.04 | Seek Image of Hupfeld Helios Roll Label, from Niels Berkers |
| 2009.05.27.04 | Seek Hupfeld Helios & Clavitist-Universal Scales, from Niels Berkers |
| 2009.05.11.05 | History of Hupfeld Helios Orchestrion, from Brian Smith |
| 2000.08.04.12 | FS: Hupfeld Helios Tracker Bar, from Brian Thornton |
| 2000.07.29.08 | FS: Hupfeld Helios Tracker Bar, from Brian Thornton |
| 1999.06.10.11 | FS: Hupfeld Helios, from Bill and Dee Kavouras |
| 1998.03.24.11 | Hupfeld Helios Soft Swell Control System, from Brian Thornton |
|
