# Yamaha CS-5
“In working order, I have tested the EXT-IN using another synth (yamaha DX100 also for sale, see other items) the EXT-IN is a cool feature of this synth and allows for the filler to be used on an external sound source and then the various knobs to be tweaked in real time to trigger some amazing sounds.
This synth pre-dates midi but does have the CV out which can be used with a MIDI convertor.
I have tested all the Knobs and switches, all do their job, a couple of crackles on the VCA intial Level and the VCF switch, but all the main switches/knobs like the Cut off Freq, Resonance work just fine.” Link