via this auction
"Model 500 Pro-FX unit stores 64 programs based on where you have your pro-fx modules dialed in at. 3v battery keeps the programs in memory. Programs can also be dumped to tape. Unit and modules also have CV (Control Voltage) for use with external modules, CV pedals and such.
# There are 4 four channel stereo mixers (level and pan)
# There are 2 parametric EQs with each portion switchable on/off
# Power cord is included
# Other units such as distortion, delay/flanger/chorus and external reverb tank can also be used in this unit. The majority of functions in these modules all work with the exception that there are discrepancies in gain in some of the mixers with one input channel not working in one of the modules. Also, one of the modules has DC noise on the output when the dials are turned... These units do use the Curtis (CEM) 3365 dual VCA."






































