@rvpiano there is something else you might try. Your CJ preamp is capable of 20 volts output. The Benchmark amp has three gain settings. Try setting the Benchmark gain to a lower setting. Hopefully it isn't already at the ~2v setting. Krell has been known to run one stage of the amp high into the next stage, giving the dynamics a boost.
Mick designer of Supratek believes line stages must have high output for this very reason. He realizes it won't be optimal for every amp and system, so the linestage as adjustable volume and another control for output voltage. My PS Audio S300 amp has an stage in it and 10db more gain than the Orchard Audio Stereo Ultra DMC V1 amp. I have to change the preamp to match the amp. Your amp is providing the same adjustment.
Good luck,
aldnorab