I had a D-85 before I got the portabilzed C-605, and it had the same type three keyboard setup...the sound was analog, and pretty good for the day...it weighed a ton.
The motorized faders on the FS-series were troublesome Don...did you ever have to get them fixed?
The FS-500 was quite the instrument all the same...I use to play one for hockey games at the local arena....the Brass Sounds were very strong...you had to be careful.
They had it piped into the house speaker system.
Ian
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.