I just went through what might be a similar issue to what
you may be hearing with Redbook CD.
I had been using an Oppo-93 SPDIF out to my Yggdrasil Analog
2 with a Jorma Digital cable (RCA at Oppo, BNC at the Yggdrasil). I was never quite satisfied with the
sound. It seemed to be somewhat mechanical,
bleached, or lacking tonal densities, with the mid-bass sucked out, and an
emphasis on the treble. From memory, I
seemed to recall getting better overall quality sound when I was using a CAL
Delta transport with a lesser DAC (CIA VDA-2) and cabling.
I had read the Oppo 93 had high jitter and knew that was a
problem. I also speculated that something might be occurring with the PCM conversion
as the clocks in the Oppo are a different frequency than a dedicated CD
transport, and error correction methods (Reed-Solomon or something else) could
differ.
On a whim, I tried another Blu-Ray player and heard a
difference. That was enough to convince
me to get a dedicated CD transport. I
recently purchased an Atoll DR-200 Signature, and the sound is significantly
better. Now, CDs sound more analog and
fluid , tonal densities have improved, the mid-bass is back. The system “boogies” again!
I’d suggest you try another transport. Even as a simple experiment, another Blu-Ray
or DVD player. Even better, would be
trying a CD player or transport that uses a dedicated 44.1 kHz clock.
Perhaps the problem is not with the Oppo as a transport, but eliminating it as a variable should yield some useful information.