Scott, I think, perhaps, the most important point of Dave's investigation may be that it recognizes there is something to be investigate. Meaning, there are time-domain distortions associated with bandlimited sampling and reconstruction. Attempting to quantify the subjective impact (if any) of such distortions on music reproduction is a seperate thing. I've found the first task is simply getting the basic recognition that frequency-domain performance doesn't necessarily alone define technically perfect reproduction of a signal. It may also depend on how sensitive the signal and the receiver are to time-domain distortion. In the case of digital audio, the receiver is the human hearing system. After that recognition, the rest becomes a debate over the audible significance.
I haven't yet examined Dave's research, but will check out the link you provide, thanks. I would add, however, that the time-domain questions aren't single dimensional. By which, I mean that a typical digital audio recording and playback chain will have multiple impulse reponse functions stemming from the multiple bandlimiting filters in the chain cascaded with each other. I've suspected that these cascaded functions may be dynamically interacting with each other to deleterious effect. Perhaps, there is an effect taking place which is akin to the multiplying of distortion order when cascading stages of a linear amplifier. But that, admittedly, is only conjecture.
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CD's are awesome. Audio coded in 16 bits on an optical dsc that costs peanuts to manufacture, and if played on decent equipment provides a thoroughly immersive musical experience. Sure, LP's sound wonderful, but they wear out, they click and pop and you need a finnicky TT and pickup to get the best out of them. Something which seems to have been completely lost on the audio illuminati. So,let's stop all this whining about how bad CD's are and enjoy the effing music.
ticknpop, you ask a useful question. Yes, I once designed the analog electronics for a CD player, however, it was never built. I think that one of the BIGGEST reasons for less that adequate quality in high quality digital playback IS the ANALOG CIRCUITRY, and perhaps Xtal stablity, and power supply quality.
At this time, I have commissioned an OPPO to be modified. It is late in arriving, but I am hopeful that it will arrive, sooner than later. I am getting a discount on the mods, so I can't complain too much. For sure, we will heavily modify the analog circuitry and the power supplies.
Something that I did find important was the basic weakness of the regulated power supplies above 1 Meg Hz. They are just invisible. My first high speed shunt regulator was designed for the CD player and later adapted to the CTC Blowtorch power supply.
For the record, I generally don't like digital playback. I just will not listen to it for more than a 1/2 hr or so, before I am bored. Not true with quality vinyl recordings or analog master tapes. Why, I can't be certain, perhaps I formed MY sonic impressions BEFORE digital became available, and I can sense the LACK of something. However, I have heard GOOD EXAMPLES of digital playback, whether it is a particular CD or a really high quality digital playback system. I have also heard extremely expensive digital playback systems that seemed to do everything right, on paper, but just sounded lousy. No expense spared in these set-ups, and even though I should have been beholden to the person who paid my air fare to hear it, I found it marginal, nonetheless.
We all know that digital is improving, becoming more than just the minimum CD quality, at a still lower price, so there is hope IF not for me, than for everyone else. I will make my evaluations when I get my OPPO.
At this time, I have commissioned an OPPO to be modified. It is late in arriving, but I am hopeful that it will arrive, sooner than later. I am getting a discount on the mods, so I can't complain too much. For sure, we will heavily modify the analog circuitry and the power supplies.
Something that I did find important was the basic weakness of the regulated power supplies above 1 Meg Hz. They are just invisible. My first high speed shunt regulator was designed for the CD player and later adapted to the CTC Blowtorch power supply.
For the record, I generally don't like digital playback. I just will not listen to it for more than a 1/2 hr or so, before I am bored. Not true with quality vinyl recordings or analog master tapes. Why, I can't be certain, perhaps I formed MY sonic impressions BEFORE digital became available, and I can sense the LACK of something. However, I have heard GOOD EXAMPLES of digital playback, whether it is a particular CD or a really high quality digital playback system. I have also heard extremely expensive digital playback systems that seemed to do everything right, on paper, but just sounded lousy. No expense spared in these set-ups, and even though I should have been beholden to the person who paid my air fare to hear it, I found it marginal, nonetheless.
We all know that digital is improving, becoming more than just the minimum CD quality, at a still lower price, so there is hope IF not for me, than for everyone else. I will make my evaluations when I get my OPPO.
What? We all have to agree with you, or else we're whining? Listen, you are entitled to judge what you hear from CD, but you are not entitled to judge what I hear. Okay?
I can assure you that, unless you abruptly begin to try to pass a kidney stone, you will enjoy that jazz more than I enjoyed the pieces last night (although there were moments and even a couple of nice pieces).
One thing I'd have loved to see: the peak SPL for some particular percussion sounds. The church was a bit more live than ideal, but for most of the music served well. But there was a piece for flute and diverse percussion, and one struck instrument in particular was excruciating. I could hear IM distortion quite audibly. Later a violinist was producing such abrasive sounds on her fiddle that I pratically expected her to begin to saw it in half. I remarked to my friend Ursula that the next step would be to set it on fire, a la Hendrix.
But that's probably been done. In "New Music", like sex, if you can think of it someone has already done it
Showing steps and impulses is one thing (and unrealistic), the pictures of these distortions with real instruments are far less dramatic. I would welcome a chance to be shown contrary evidence. In the mean time I enjoy many CD's and the CD's that I have made from select LP's and think the music biz has far more important things to improve.
Sounds like fun, but how about being a serious musician and geting asked to perform one of these pieces. A woman friend described playing in a piece where the score abruptly stopped and said simply that there is a can of rocks on the floor pick it up and do whatever you want with it.
Unfortunately, inherent in this notion is that old bias of deeming a measurement which doesn't appear offensively to the eye is therefore, not offensive to the ear.
Reminds me of the late Charlotte Moorman, a cellist beloved of the new music folk, who variously performed in the nude (with a breast draped over the instrument, and another time underwater.
More seriously, if, in a number of pieces last night, a single fragment or two were used for development in a movement, allowing for repetition, transposition, and various other transformations in the service of the music, there could have been some interesting music, and comprehensible music at that --- even (gasp) beautiful music. But most of the composers in this realm are afraid to write anything resembling a tune, afraid to repeat anything for the most part, lest it sound somehow trivial.
At least most have moved away from serial composition, epitomized by Webern (at least his pieces were short).
There is a chamber music series that I support that does have some stylistic guidelines and attempts to get composers who are willing to adhere, and has funded some beautiful music over the past 25 years. I spoke to the founder and artistic director last night and commented on the rather formulaic gestures in the first piece on the program. It turned out that he had, at the urging of a friend, asked the composer for a new piece. The latter declined after reading the guidelines. That same person has done some film scores and achieved a fair measure of success thus. I told my friend that I suspected, when asked to provide new "absolute" music, often such composers want to go out of their way to show that they can write music as "difficult" as anyone when given the chance, and he agreed.
measure the wholechain
I am pretty sure I said awhile back here -that one needs to measure the whole entire chain and not one or two pieces of equipment in isolation to see what the distortion is in total... that which we have to endure in listening to hifi music. The recording chain and the playback chain... I would bet a whole dollar that it is pretty ugly.... Doing such an exercise will point to the culprits responsible for the such miserable state of hifi after so long. We know two major points are the recording methods and the speakers and the way they are used etal. But, almost as bad is from recording mic preamp to power amp speaker terminal as a whole string/chain. -RNM
I am pretty sure I said awhile back here -that one needs to measure the whole entire chain and not one or two pieces of equipment in isolation to see what the distortion is in total... that which we have to endure in listening to hifi music. The recording chain and the playback chain... I would bet a whole dollar that it is pretty ugly.... Doing such an exercise will point to the culprits responsible for the such miserable state of hifi after so long. We know two major points are the recording methods and the speakers and the way they are used etal. But, almost as bad is from recording mic preamp to power amp speaker terminal as a whole string/chain. -RNM
well yes what do you expect if you saturate tiny rust particles glued to a piece of mylar being dragged across over, around, through a maze of metal and plastic guides, idlers with mechanical speed variations from seconds down to uS in motors, bearings, stick slip
set the “0 dB” level to where the tape is saturating enough to give 3% 3rd harmonic distortion – then regularly record above 0 db
don't forget to "dither" those saturating particles with 100+ kHz AC bias if you want any low level linearity at all - at least for those particles that didn't fall off with all the rubbing or get remagnetized by the adjacent layer of tape...
repeat the record/playback a few times in mastering, editing - likely move to a different tape machine for feeding the cutting lathe - hope the tech really knows what to do with the head alignment, frequency test tone tracks you did remember to include on the master
could write several times as much about the vinyl cutting, replication, playback process off the top of my head but dinner calls....
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John - i have an OPPO with upgraded power supply that I primarily use as a transport for my PMD 200 equiped 1704 Burr Brown DAC (last version of the HDCD decoder ) 24/96 with jfet analog stage. I find the Oppo 95 analog stage even with upgrades not much better than older CD players - the analog stage still needs a lot of work, even though it's marketed as the cats meow of modern players with it's 32 bit 192 khz Sabre DAC . It's a great universal transport though and sounds better through older DACS which have more room to build shunt regulators and discrete output stages
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ticknpop said:
I've heard many very favorable reviews of the Oppo 95 via it's analog stereo output, even in comparison to some $5000 DACs. I don't have the Oppo 95 but the older Oppo special edition with NuForce mods (Nuforce Edition). Has the same Sabre 32 DAC. It can sound very very good, with good source material.
Subjective opinions vary of course, though many say the Oppo sounds laid back. I heard one person prefer his upfront sounding older DAC.
But, I've had expensive CD Playback in our system, and the Oppo has been my personal favorite, plus it plays all different formats. I prefer it our Sony SC1 and Benchmark DAC though the Benchmark is close. The Oppo seems to have a more full bodied sound.
Just my subjective opinion though. We all have our preferences. And we all have different systems, so one component may compliment one system better than another.
John
One thing I was going to mention to JC, but didn't was how good many HDCD recordings can sound on the Oppo, even when compared to good SACD or Bluray. I never know what stuff is HDCD encoded till I put it in. But it's nice to see that it's still being used on some new popular music.
John
John
For the record, 0Vu on the meter of an Ampex master recorder initially represented 1% distortion in about 1950. By 1968, the distortion had dropped to about 0.7%, following significantly further in the next 10 years by at least 4 times, maybe more. Some people reset their Vu meters to a higher operating level, but not everybody.
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