I'm running a McCormack DNA-500 (10kohm input Z) with a Dehavilland UltraVerve (600 ohm output Z), and the combination is terrific.
The impedances you are dealing with are probably in the same ballpark. If you stick to the 10 to 1 rule, i.e. the amp'z input Z should be at or greater than 10x the output Z of the preamp, you should be ok.
The impedances you are dealing with are probably in the same ballpark. If you stick to the 10 to 1 rule, i.e. the amp'z input Z should be at or greater than 10x the output Z of the preamp, you should be ok.