Can I use the stock dc servos with bei encoders with new servo drives or would I have to replace the motors to

Can any one recommend good drive to use with them?

Thanks ,john

You can certainly use the stock servos as long as the encoders are 5v square wave.
You can also use the original amplifiers if you use one of the external controllers that are capable of sending out analogue voltage (+/- 10v)
I use the CSMIO/IP-A on my Chiron and it is the best controller I have used.
The others that can do that are the DSPMC , the  Kflop and the Galil.

Hood