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New high resolution SACD releases, players and technology.

Not necessarily

*** I really don't think the quality of DVD sources requires more than 24 bit floating point architecture ***

There is no such thing as "24 bit floating point architecture" - that would imply a 15 bit mantissa and 8 bit exponent plus a sign bit, which is clearly not enough to process 24-bit words.

The minimum required to process 24-bits resolution in floating point is a 32-bit representation.

24-bit fixed point is susceptible to round-off/truncation errors - and requires very careful scaling of intermediate results and a 48-bit accumulator. The Meridian approach of doing it entirely in 48-bits is a smart one, but requires twice the processing power.

But if you examine the link that i provided, even a casual numerical analysis would show that the algorithm is very difficult to implement in 24-bit fixed point. A bad implementation could easily reduce the accuracy of the final result to around 8-12 bits. Even a 32-bit floating point design is susceptible to quantization if care is not taken. A 64-bit implementation is ideal because it allows full 24-bit resolution to be carried throughout the entire processing chain with absolutely no danger of truncation even in pathological situations.

*** There are (or were) some much more impressive pre-pros you haven't mentioned: Bel Canto, EAD and Sim Audio (modified EAD) in particular. ***

I haven't heard them, which is why i haven't mentioned them. EAD and Sim Audio are still based on the 24-bit Freescale DSP though, don't know about Bel Canto. In general, I would stay away from any Freescale design apart from the Meridian. In addition to the 24-bit issue, Freescale doesn't provide certified DSP decoding libraries, unlike the other manufacturers, so you either have to rely on an in-house development team (very expensive R&D - hence the high cost of Meridian), or outsource to an outfit like Vinci Labs. I have nothing against Vinci Labs - they do good work, but it reduces the differentiation across models, and I would question their ability to sustain innovation given their limited R&D budget compared to someone like TI. Look at their ability to offer room eq, for example, it's still "coming" but TI and Cirrus Logic have working implementations. And someone like Audyssey isn't likely to write code for a 24-bit platform - it will be nearly impossible to optimize something as complex as that in fixed point.

I haven't opened up my Cary yet, but I suspect (based purely on the specs) that it is using the CS49400 DSP - not a bad chipset, and comes with a good DSP library, but not the latest and greatest. And there are some annoying quirks in the Cary implementation - no DPL2x layering on top of DTS for example.

PS - You may want to do a search on the Vinyl Asylum. A wall shelf doesn't necessarily improve vinyl performance, it depends on your house and your turntable. The general idea is that in a house with a wooden floor (or if you system is on an upper floor), the walls offer better rigidity and avoid floor vibrations. I nearly bought a wall shelf a few years ago, but based on advice from knowledgeable vinyl inmates, I'm glad I didn't since it's debatable whether it would have yielded an improvement in my situation (my house is built on a concrete slab).


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