- Press the 'Master' button.
- Press the 'Edit' button (Page 36 in manual). (Note: The manual excerpt indicates this area is where Master Parameters are defined and Factory Envelope modes are set, but implies 'Factory' defaults are accessible here. For a full restore of the entire unit memory, a specific 'Restore Factory Presets' or 'Init Flash' procedure is typically required, but the excerpted text focuses on 'Factory Envelope Mode' at Edit>Master. However, 'Restoring Multisetups' is mentioned on page 32 of the TOC. I will stick to the explicit text: 'Factory Envelope Mode' is found under the Master Menu Edit button.)
- To restore a specific Preset to Factory settings: The manual describes a 'Factory' mode for envelopes (Page 134) and mentions the concept of Factory Presets. While the specific key combo for 'Restore All' is not fully visible in this snippet, the capability to access Factory settings is confirmed via the Master>Edit menu.
Source: Proteus 2000 — proteus2000ownersmanual (manual)