Originally Posted by George Mills
Originally Posted by VirusKiller
Three things:

1) I'm pretty certain that the 518 and subsequent Meridian resolution enhancement "stretches" the signal to the new word size rather than adding zeros in the LSBs.

No way it does that. The way SPDIF is implemented you can't.

Like Steve said a bunch of posts back. You can kind of think of SPDIF as ALWAYS 24bit. It's just a matter if these VERY low level bits are used or not.

Thinks of CD's as really 16bit with least significant 8bits as 0 (WHEN TRANSMITTED over SPDIF). If you just stretched that you push real good audible bits down into the abyss you can't hear.

518/568 MAY internally stretch 16 it out to 72 bits. But once it gets back to SPDIF and it has to be more or less on the same volume scale as what came in. Which means the most significant 16bits HAVE to stay as the most significant 16bits.
I'm not convinced of this as it seems contrary to everything the 518 is designed to do. The 518 manual states that dither is applied when performing a "Step up in dynamic range". This would only be necessary if a non-trivial DSP operation is being performed.

However, I accept this is unclear. Maybe I'll do some experiments with my Tascam when I (eventually) get home. (Holiday extended by six days minimum at the moment...).

One thing's for certain though. Adding my 518 in front of all my stereo sources prior to Radiance/HD621 will be a good thing to do, particularly if I can automate the amount of digital gain on a per-album/track basis.

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