I sent an email to Paul Blakemore at Telarc regarding the recording/mastering processes in the manufacturing of Telarc CD's (or the CD layer) and SACD's. Paul is an "Audio engineer/editor" for Telarc, and has done all the mastering in converting the Soundstream recordings to SACD's. It's been my contention that no additional work is done for mastering an SACD than for a CD, and that the SACD layer sounds better simply because the SACD itself is better. Not all AR members agree, but Paul enthusiastically does, and sent me a very lengthy and detailed email explaining why.

He explained very thoroughly the difference in the actual recording by the Direct Stream Digital (DSD) process and the PCM process used for CD's. His description is far too lengthy and detailed for me to copy here, but the basics were that the sampling rate of DSD (at 2,8 million times a second) vs. that for PCM (44.1 thousand times a second) allows for a far more accurate musical waveform, as well as greatly increased dynamic range.

All Telarc discs today are recorded via the DSD process. Nothing whatosever is done to a classical DSD recording in transferring the original to an SACD, but the manner in which that DSD recording is transferred to a CD is very interesting:

"The DSD is then simply re-recorded to PCM in a straight transfer after the volume is set for the loudest spot. We use this analog re-recording process from DSD to PCM because we found in repeated listening tests that it sounds better than a digital "downsampling." Theoretically, the direct digital downsample should sound good, but we found that because of the amount of mathematical interpolations that are vinvolved, they actually don't sound very musical. Much of the perception of depth in the stereo image and warmth of the sound is lost or degraded in a digtal downsample."

This would explain why the "redbook" CD of DSD masters sound as good as they do. Telarc has stated too that the CD layer of a hybrid disc, and the redbook CD of that same recording are identical. It also explains why the 50,000/sec sampling rate of the Soundstream recordings didn't translate very well to CD, but now do on being remastered as SACD's.

Insofar as compression or limiting on classical pieces, here is Paul's response:

"I can assure you that on Telarc's purely classical orchestral recordings, whether on SACD or CD, there is no comopression, limiting, or other such dynamic range control used in mastering either the CD version or the SACD version. This would defeat our desired goal of maintining the dynamic range of these kinds of music products. I know, because I master many of these. I also know what techniques Michael Bishop and Robert Friedrich use for mastering straight classical releases, and believe me there is not any mesing around with the dynamic range."

"There is no "mixdown" back at the studios. the best musical performances in the various "takes of the stereo recordings are simply edited together to make the master. There is no additional signal processing or messing about with the sound." (Italics, mine.)

I'd say that answers that question pretty thoroughly and accurately. .