Hi.

rule of thumb, don't go any longer than 50 feet with RS-232 serial.

Yeah, but I have used a RS422 serial cable (with one converter to RS232 on each end) as long as 150feet to connect my empeg. Worked great.

I probably won't ever do that again though. It was only a test to check the cables, and my empeg was the only serial device that was available at that time (apart from my PC obviously).

cu,
sven