The Model 38 ELF ADSR is a full-featured, wide range Attack, Decay, Sustain, Release (ADSR) Envelope Generator that fits comfortably into a 4 HP parking space. Part of the ELF series arsenal, standard features include an internal trimpot which sets the maximum event range varying from 'standard' keyboard applications (1ms to 10 seconds per phase) to ridiculously long events of over 10 minutes in duration. Four manual controls set the timing of both the Attack, Decay and Release phases and the Sustain level. An LED indicates the output state in realtime.

Expandable architecture via Model 38A

The optional M38A Expander augments the expression of the M38 by adding four independent voltage control inputs (one per envelope phase), and a Retrigger function. Brought into the circuit by an internal ribbon cable, the M38A requires a parent Model 38 ADSR to operate. Only one Expander may be added to a single Model 38.