DVD-A/SACD v PCM - tunes for judging the improvement

[sfdoddsy]

I've been buying a few DVD-A and SAC discs in recent months and finally got a DVD-A and SACD player to listen to them on.

However, about the same time I did that I changed my speaker system to one that uses a digital crossover and EQ system. This means it redigitizes the signal, theoretically losing the advantage of the hi-rez formats, although I bought them in fact for the discrete multichannel.

However, I'm curious to see what I'm missing out on, and whether the tradeoff from the digital EQ outweighs the loss of the highest resolution. It does with ordinary PCM.

Now I'm trying to work out the best way to do the comparison. Swapping in and out a three way active crossover and matching EQ channels won't be easy, but I do have the required analog crossover and EQ.

To make the comparison as fair as possible, I'm looing for suggestions for very high quality 2 channel SACD or DVD-A that has exactly the same mix available on a separate CD. I think it should have been originally recorded in hi-rez as well.

So, any musical suggestions to show the improvement of SACD or DVD-A?

Thanks

Steve




Steve's DIY Dipoles

[JonMarsh]

Hello Steve,

Interesting problem you've got hear.

SACD's are commonly produced in hybrid format, that is, with both a DSD layer, and a "down-res" of the DSD to redbook PCM using the latest Sony SBM process (Super Bit Mapping). Ironically, most of the early Sony disks are NOT hybrid "combo" disks, but just single layer SACD, because they're produced in the first SACD plant built by Sony, which doesn't have this capability. Most SACD's produced by labels like Telarc, Hyperion, Rounder Records, FIM records, Water Lily Acoustics, etc., are Hybrid, as are the new Rolling Stones ABKO releases, and the new Police re-masters, which were handled by Bob Ludwig himself. These new SACD/PCM hybrid releases have much better mastering than the original CD releases, and go back to first generation tapes.

Unfortunately for your purposes, if you want to try to compare SACD to DVD-A, the same recordings are usually NOT available in both formats.

I have a few DVD-A disks, and the CD versions of these same disks, which enables some comparisons. DVD-A can be a very mixed bag, because there is little consistency in recording format; many are using 24/96 with Meridian encoding for a multi-channel mix, and also include DD 5.1, but don't have a stereo high res mix. Some are even "only" 24/48 in multi-channel. I have a Jonath Brookes DVD-A/V combo disk which is a DVD-V music video on one side, and high res 24/192 DVD-A on the other. There have been very few 24/192 pop recordings made.

My personal observation is that for a given amount of bucks spent on the transport and conversion, the DSD side will sound better than the PCM side. So, even $400 SACD players have something to offer, in a sense; the things that go wrong with Redbook PCM are ameliorated to a degree with high res formats, even in less than ideal implementations.

OTOH, using the CD down mixes from hybrid SACD's through my best redbook system at home, and comparing that with SACD from my Sony SCD777ES player, it's an interesting situation. The SACD sounds somewhat more natural and extended in the top end, but from the low bass through presence range, I'd have to still give the clear nod to my DIY CD setup for focus, dynamics, and a sort of vivid naturalness. The CD performance of the SCD777ES, even though it's using the same DAC's, with an upconversion process of the Redbook PCM to DSD, is not in the same class in any part of the frequency range as my main DAC.

This is true on a big system like ThomasW's dipole Acoustats, with RD75's and a ribbon line tweeter array, and it's also my perception through systems as "lowly" as my DIY 8" two way systems. The electronics in this case are both passive preamps, and using Ayre Acoustics amplification in the upper midrange to high end.

With a comparable approach to SACD, I'm sure even better results can be achieved, but in my opinion, other than the Mietner DAC, and the dCS Elgar or Delius, there is no commerically available SOTA SACD system yet.

So, to a degree, I think using a digital crossover setup as many do for their convenience dealing with dipoles is a potential issue; I'd prefer it be at least a 24/96, if not 24/192 rig, because even the majority of todays PCM 24 bit converters barely muster 21 bit performance under ideal circumstances; and if there isn't output gain control implemented AFTER the D/A process for volume control, then things could be much worse at "normal" listening volumes, because of dropping down 10-20 dB into the dynamic range of the ADC and DAC.

Now, the argument can be made that analog electronics suffer from noise floor issues too, and they do, but one has to consider the subjective weighting of low level effects, and digital, with it's issues around time clock jitter, and signal correlated jitter has some problems which go beyond the effects of nearly undetectable background hiss. Jitter issues can seriously compromise converter performance, and render what you think is a 20 bit part as something not even close to true 16 bit performance.

So, here I am, an avid purchaser of hybrid SACD's, and 99% of my listening to them is done on the CD layer with one of my DIY DAC's. Even an older chipset, like the CS8414 and CS4390 can provide some very smooth, natural sound, if the right steps are taken with power supply design, layout, and jitter suppresion, combined with non-feedback HV discrete analog electronics (my output stage runs on +/- 35V! At normal signal levels, the device capacitances and idle current varies hardly at all up to full CD output voltage, which means the open loop THD and IM is very low.) So, while I appreciate the efforts of tweakers who seek to figure out which opamp to upgrade their CD player with, I think that's more of a diversion rather than the solution.

But don't forget, I'm the analog curmudgeon around here, so don't take my comments too seriously, but by all means trust your ears...

I suspect you can get very good performance with your current system, and the limitaions with the digital crossover may be more than offset by the benefits of the easy EQ and the advantages of dipole system performance. But in thinking, what will it take to get to that next level, someday, you will probably want to revist that part of your reproduction chain.

Best regards,

Jon




Earth First!
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We'll screw up the other planets later....

[sfdoddsy]

That's kind of what I'm thinking, and since I will have the software I can change later. And 1000+ CD v 20 hi-rez or so is no reason to change now.

However, I am curious to hear the benefits of hi-rez, and also to see whether those benefits are still valid even when re-digitized.

I'd thought about using Patricia Barber's 'Modern Cool' since I use it for evaluation anyway, but apparently the remaster to SACD was remixed as well. Ditto the new Stones SACDs.

So initially, I am going to burn a CD copy of the mix on a couple of hyrbid SACDs I have (Mischa Mengelberg is burning now) and load that in my CD player so I can flick between that and the SACD.

This way I have a base to compare hi-rez through my system as it is, and also through the analog crossover and six channel analog parametric EQ I bought recently for center and surround use.

But more tune suggestions would be great.


Steve




Steve's DIY Dipoles

[JonMarsh]

Not knowing what your tastes are, it's not easy to recommend. But most everyone I play Alison Krause for enjoys her. "Forget about It" is the hybrid SACD title. The new Sting remasters are excellent, so if you're into pop, and familiar with the old ones, one of those would be a good choice. I like the Hyperion classical disks quite a bit, and most of Telarc's are very good, too, including there new Carmina Buranna release. Plus there's some great Jazz on Telarc, like Oscar Peterson.

To do a test like you're talking about, you might have the best luck if you can find a dealer that sells the higher end units, and will allow home demos. Many high end dealers in the US do this, but it's also true that many of them don't carry SACD yet, or are just getting into it a bit, because their existing lines don't make a player. This is why Sony came out with "statement" players like the SCD-1, and the SCD777ES, because no one else would be offering them for a while.

Last, my point regarding conventional PCM is that the quality you get is very dependent on the quality of the implementation, as well as the digital signal transport. Timing errors (jitter ans so forth) in the internal circuitry can degrade performance substantially over the specs, and because for many of these units, it's signal correlated, it's much wose with real music or signals like Dean Jensen's spectral contamination test then for the single sine tones usually used for testing.

This is what concerns me, because to my ears, the analog inputs of every pre-pro I've heard to date (which do basically the same thing with an input ADC as a digital crossover EQ unit) suffer from "digititus", re what they do to the analog signal, and they don't generally do PCM CD SPDIF inputs justic either. Just compare how these Pre-pro's perform on analog or digital inputs, with the performance of a good upsampling/re-clocking DAC like the Music Fidelity A324.

Best regards,

Jon




Earth First!
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We'll screw up the other planets later....

[sfdoddsy]

Yes, I have the HYperion 'Coronation of King George' disc - very nice.

However, regarding the type of SACD player employed in testing. It seems to me that if you can only hear real differences using a high end player, then those differences might be smaller than is often mentioned.

Steve




Steve's DIY Dipoles

[JonMarsh]

On any SACD player at any price point that I've heard - from $300 to $5,000, the DSD layer of a hybrid disk sounds better than the CD layer on the same player. So, in the sense that at $400 you can probably get better overall sound with SACD than with just CD, due to the benefits of the "Hi Rez" format, it's a no brainer. But just how high a res you're really getting is all dependent on the gear and the implementation overall. This is just as true for SACD as it is for CD.

Problem is, we can't compare a moderate price yet relatively SOTA CD player (like, say, the Ayre CX-7) against a comparable SACD player, becuse the latter doesn't really exist as far as doing the implmentation on a comparable level (ultra low jitter clocks, non feedback wide band balanced differential D/A, non feedback low distortion class A output). But hopefully, someday it will.


Now, the $64 question is how good are the digital electronics in units like the driver rack, the Rane, or the new Behringer? Especially, since they must include ADC, as well as a D/A. This is where I have substantial reservations, but do keep an open mind that the benefits- the ability to implement a high quality dipole easily, and the benfits which devolve from that, compared with typical monopole speakers (and rooms), outweigh the costs.

Best regards,

Jon




Earth First!
_______________________________
We'll screw up the other planets later....

[Brandon B]

Not knowing what your tastes are, it's not easy to recommend. But most everyone I play Alison Krause for enjoys her. "Forget about It" is the hybrid SACD title. . . .
Jon

Add her "New Favorite" album to that as well.

BB

[JonMarsh]

Yup, got that one too, it's very nice, though closer to her bluegrass roots; "Forget About It" is more of a crossover album.

~Jon




Earth First!
_______________________________
We'll screw up the other planets later....