Gulbransen E4 audio issue

[Guest]

All of a sudden my Gulbransen E4 this week got laryngitis. Not sure how to explain the terrible sound it's making. It now sounds like it's an old fashion gramophone. Does anyone know how to fix it? Would like to add midi function to it to so I can use the console with Hauptwerk or add other instruments to it such as piano or chorus.

[tucsondave]

The first thing to check is the power supply. All voltages should be DC with no AC component. There are 5 supplies. +33v and -33v for the amp, -4v for omega, +10v for keying and expression lamp, and -13v for magnets.

Keying is DC so adding a MIDI interface shouldn't be much of a problem.

td