Since last trying the Benchmark directly to my amp I've changed it's power cord to the Cardas GR and the nickel plated outlet to the Oyaide SWO-XXX. All the time running through my tube preamp to amp.
Trying it again directly to amp with the new PC and outlet and I must say I'm very surprised by the results (rca to rca). Perhaps the GR power cord and the SWO-XXX reduced the harshness and quieted the background noise. But for the first time I'm not unhappy with the sound of the Dac1 to directly to the CJ2500a.
Oh, I've also added the DH Cones. Thanks Cmk....