[analogsurviver]

  What the heck does vinyl have to do with DSD? This conversation wanders more than the Lost Tribes of Israel.

Like DSD128 being the only digital so far that is "kind of" capable of capturing 1 kHz square wave from analog test record with all its particularities that, although should not be there in the first place, actually are very good indicator of  the quality of the analog vinyl playback ? Ever even seen how does it look like, let alone understand the reasons why it is like that ?
 
I miss some of the high frequency detail from turntables even in DSD128 recording - and that means certain defects in replay still can not be documented otherwise than connecting the turntable to measuring setup - which can be EXTREMELY hard logistic problem. Ever set up a turntable really well and had to dismantle it for transport and set it up again at least in the ballpark of the precision once already attained - just to be able to take measurements ?
 
With 44.1/16 being UTTERLY useless in this regard ? With anything PCM up to 192/24 "ringing-or-whatever-you-want-to call-it" more or less precisely where you want it to be clean so that you can see what the cartridge is really doing ?
 
Something like that...

 

[bigshot]

LP records have nothing but noise above around 15kHz.

 

[Wizz]

   
It is ironical that the "flat earth" belief is actually the result of naive subjectivism (after all, it obviously looks flat from where one is standing, so it must be true, right ?), yet keeps getting brought up in its defense.

Was thinking along the same lines! ☺
 
Flatearhters have the exact same mindset as these guys.
 
- "my eyes can't be fooled: the earth is flat" / "my ears can't be fooled: 24/96 sounds better than 16/44.1"
- "actually science proved that it's not flat" / "actually controlled listening tests showed that nobody can reliably tell the difference between 16/44.1 and 24/96"
- "I choose to trust my eyes, science is wrong, I know for a fact the earth is flat" / "I choose to trust my ears, these listening tests are flawed, the gear used is not good enough anyway, I know for fact that 24/96 sounds better than 16/44.1"
 
Oh, they'll wake up someday I guess... you can't sleep your whole life long. Or can you? (*shivers*....)
 
This said, I haven't listened to DSD yet, so who knows, maybe I'll have to eat my words and make amends..? I doubt it, but I'll keep an open mind.

 

[Wizz]

  Like DSD128 being the only digital so far that is "kind of" capable of capturing 1 kHz square wave from analog test record with all its particularities

 
References please?

 

[analogsurviver]

  LP records have nothing but noise above around 15kHz.

Not true. Not if at cutting the master lacquer ( or DMM ) is not decided to filter out HF content "to make it easier".
 
It is hard to maintain more than approx 30 kHz on vinyl in the long run ( a single play with an inappropriate stylus/cartridge can shave higs away ) - but it CAN be done. All the way up to whatever the cartridge is capable of  -
and although by accident, it was possible to cut in the record master bias frequency of the analog recorder - exceeding 100 kHz.  
 
This is tough to play back - there were only less than 5 cartridges capable of playing beyond 100 kHz back.
None is in the production anymore ( ecological reasons ) - but cartridges that are essentially/usefully flat to approx 50 kHz are quite numerous in today's market.
 
Using less than real time speed analog record mastering, it is possible to cut frequencies up to at least 
25 kHz divided by the cutting speed - for half speed 50 kHz is reached, for 2/3 speed 37.5 kHz etc. There are cutting heads that can go real time to 27 kHz and beyond - and can extend the bandwidth accordingly.
 
This is roughly frequency response of the DSD128- exact figures depending on the output filtering.
 
It is the minimizing the VERY high frequency ( >> 50 kHz ) noise that gets generated whenever the stylus is approaching mistracking due to tracking low frequencies at high amplitude that I am particularly interested in;  those cartridges that produce less of this noise invariably sound better - and are also apreciably quieter in the groove. I can see that noise on the 100 MHz oscilloscope, but it is MUCH lower in amplitude on DSD128 recording. It can be "heard" as audible noise during tracking of say 300 Hz at ever increasing amplitude; although no hard mistracking is allowed, some cartridges "noise" much more - or less - than others during tracking the higher amplitude signals, despite having roughly similar frequency response. I would like to find out what causes this unwanted behaviour.
 
Vinyl records are in fact a lot less noisy than generally thought; most of the "noise" is in the turntable/cartridge/arm in form of mechanical resonances getting excited, not in the record itself. 

 

[Don Hills]

  Like DSD128 being the only digital so far that is "kind of" capable of capturing 1 kHz square wave from analog test record with all its particularities that, although should not be there in the first place, actually are very good indicator of  the quality of the analog vinyl playback ? Ever even seen how does it look like, let alone understand the reasons why it is like that ? ...

Do you assert this as a result of what you hear, or because you have scope pictures to prove it? Pictures taken using an analogue oscilloscope to display the analogue output, not a digital sampling scope? Remember, this is the Sound Science sub-forum.
 
Somewhere in my paper files I have an article from the 80s which includes a SEM photo of the square wave groove on a CBS STR-112 disc. It clearly shows ringing of the cutterhead on the square wave "edges" (on an LP, a square wave physically looks like a triangle wave.) Ironically, cartridges which most clearly show this ringing are the most accurate...

 

[bigshot]

  Not true.

 
Yes it is. I produced an LP back in the day. At the cutting stage, along with the RIAA curve, they applied a high frequency roll off to prevent ultra high frequencies from prematurely wearing into distorted mush. As I remember, the roll off started around 15kHz. Not anything that would affect the music.
 
It doesn't matter what a cartridge is capable of playing back. Those frequencies aren't in the grooves. Any frequency above the rolloff is just noise from imperfections in the vinyl.

 

[RRod]

  Do you assert this as a result of what you hear, or because you have scope pictures to prove it? Pictures taken using an analogue oscilloscope to display the analogue output, not a digital sampling scope? Remember, this is the Sound Science sub-forum.
 
Somewhere in my paper files I have an article from the 80s which includes a SEM photo of the square wave groove on a CBS STR-112 disc. It clearly shows ringing of the cutterhead on the square wave "edges" (on an LP, a square wave physically looks like a triangle wave.) Ironically, cartridges which most clearly show this ringing are the most accurate...

 
If you could find and scan that pic I'd love to see it. Do the graphs in this post reflect typical square-wave activity in vinyl?

 

[castleofargh]

the famous DSD is analog is marketing genius. I hope the guy who thought about that got himself a giant pool for his house with that communication strategy. a sample is a sample, they made it 1bit so that they could put a lot of them in, but there is only so much you can write in a 1bit sample ^_^. and between that sample and the next one, there is still a all bunch of nothing just like on any PCM. nothing went analog, they just used more samples to say the same thing.
 
 
 
if some want to argue on a pure objective level that DSD is better than 16/44, sure it is. we all know it. but is DSD better than 24/96? no it's not, and we also all know it.
the 1bit signal is BS, most DSD DACs are PCM delta sigma set to do the trick. and real DSD DACs tend to now go with several bits because it was such a stupid idea to use only one bit from the start knowing that the resulting noise would be a disaster.
 
but when the oldschool audio elite spits on delta sigma because it's adding lot of noise compared to discrete good old R2R DACs, the same guys acclaimed DSD that had a lot more noise and used the exact same voltage up/voltage down system that you get on a pulse modulated DAC. on PCM you have 2 sample values and the DAC will generate the proper series of ON/OFF rapid actions to get from sample A to sample B.
on DSD the signal is already ON/OFF orders. the result is pretty much the same, it only required more data to get the same result.
 
DSD goes a lot faster when it comes to samples so it could record more ultrasonics for no reasons. that is true, but after all the heavy trim job done with noise shaping to get it out of the audible range, you still have to cut it out. else it might actually be a real problem for your system(and again were talking huge noise will lot of energy from 1bit, not from 16 or 24bit quantization). so in the end they cut it out at about the same place as you'd do on PCM. so no better ultrasounds on DSD!
 
 what's the result of all that? PCM 24/96 gives the same accuracy as DSD, it's almost troubling to see how close they are on most tests. and it isn't going to change much when you realize that 99% of all DSD available come from PCM masters that were reencoded.
 
oh but that's forgetting that DSD is a problem even at mastering level, and almost all the guys making DSD masters actually work on a system that turns the track into PCM for mastering and back to DSD at the end. because it is such a bad data storage medium that we don't actually have much tools to work on it.
 
 
 
 
 
 
 
so all in all, people buying DSD are buying mostly remastered PCM encoded in a difficult to handle format, that you can't actually use on most of your gears unless you convert them back to pcm(on the fly or not). the real evolution is that they successfully sold us a strong DRM shaped as a new media. and we smile while getting lied to, something us audiophile seem to really enjoy a lot.

 

[analogsurviver]

   
If you could find and scan that pic I'd love to see it. Do the graphs in this post reflect typical square-wave activity in vinyl?

Yes, they do. There is LOTS to know and consider in order to be able to interpret the results correctly. The square wave that most perfectly "approximates" the perfect square wave IS NOT the accurate representation of the signal actually engraved in the groove.
 
I also have somewhere bookmarked link to SEM pic of the ringing in test record - published IIRC in Popular Electronics early 80s.
 
I will be posting square wave from vinyl. Please have some patience - I would like to do it right. There have been some incorrect explanations, whatever  little is available online is from one, in best case 2 test records - but none from the third one. It will be shown that cartridges have FAR better frequency response than cutterheads, it will be shown how to separate "ringing" of cartridge from "ringing" of test record ( cutterhead) - etc. The best test record for testing frequency response with a pulse method was NEVER available outside JVC - that's why they were able to produce cartridge mid 70s that overall still has not been equaled, let alone exceeded. A friend had this cartridge late 70s - and it is "perfectly boring" ( a la Quad ESL 57 or 63 ) ; it will not add or remove anything from the recorded signal. We were young, hype for emerging MC cartridges was super strong, we wanted "something new" - and that JVC cartridge ended God only knows where. Pity indeed - as nowadays it is next to impossible to get and if it does show up for sale, it is serious money.
 
That in-house-only JVC test record has been mastered at 1/10 of playing speed - meaning the pulse to be good to approx 250 kHz , enabling making the cartridge that was VERY flat past 60 kHz . No breakups, high Q resonances, loss of channel separation around resonance, etc, etc. Still only wishful thinking for most other cartridges ever produced.
 
I do not own equipment to present graphs etc; will be posting actual files recorded from test records and occasional screenshot from an analog oscilloscope. Remember - digital storage oscilloscope is also a PCM device and is subject to same limitations as ADCs and DACs - and therefore will be used only as an information and not something serious. A modern day expensive digital scope might be "kind of" good enough.
 
Whenever required, the files will be DSD128 - where not, I will be 48/16 for the sake of as broad compatibility as possible and reduced file size. From these, any analysis should be possible, depending on access to/availability of test equipment.

 

[bigshot]

Every home should have an LP with square waves on it.

 

[charleski]

on PCM you have 2 sample values and the DAC will generate the proper series of ON/OFF rapid actions to get from sample A to sample B. on DSD the signal is already ON/OFF orders. the result is pretty much the same, it only required more data to get the same result.
 

Since almost all DACs these days are PDM/bitstream/delta-sigma, I think the difference really is just that when feeding them a PCM signal the DAC itself needs to perform the requisite upsampling, decimation and noise-shaping, whereas with DSD that step has already been done and the data stream can go directly to the bitstream switch. It's hard to think of any reason why one path should be better than the other, unless you're using a DAC that's very poorly engineered.

 

[castleofargh]

 

on PCM you have 2 sample values and the DAC will generate the proper series of ON/OFF rapid actions to get from sample A to sample B. on DSD the signal is already ON/OFF orders. the result is pretty much the same, it only required more data to get the same result.
 

Since almost all DACs these days are PDM/bitstream/delta-sigma, I think the difference really is just that when feeding them a PCM signal the DAC itself needs to perform the requisite upsampling, decimation and noise-shaping, whereas with DSD that step has already been done and the data stream can go directly to the bitstream switch. It's hard to think of any reason why one path should be better than the other, unless you're using a DAC that's very poorly engineered.

yup that's my point(or one of them). DSD is a niche, real DSD recorded in DSD and not PCM converted are a niche in the niche. and most of them still end up being processed pretty much the same way (except for hardcore R2R NOS DAC users). so expecting anything more than maybe a different mastering when buying a DSD is really optimistic thinking.

 

[diamondears]

Was thinking along the same lines! ☺

Flatearhters have the exact same mindset as these guys.

- "my eyes can't be fooled: the earth is flat" / "my ears can't be fooled: 24/96 sounds better than 16/44.1"
- "actually science proved that it's not flat" / "actually controlled listening tests showed that nobody can reliably tell the difference between 16/44.1 and 24/96"
- "I choose to trust my eyes, science is wrong, I know for a fact the earth is flat" / "I choose to trust my ears, these listening tests are flawed, the gear used is not good enough anyway, I know for fact that 24/96 sounds better than 16/44.1"

Oh, they'll wake up someday I guess... you can't sleep your whole life long. Or can you? (*shivers*....)

This said, I haven't listened to DSD yet, so who knows, maybe I'll have to eat my words and make amends..? I doubt it, but I'll keep an open mind.

That's the point. You got it. Exactly what I'm saying. Bfreedma totally missed it.

 

[castleofargh]

http://sdg-master.com/lesestoff/attachment.pdf
 
you think what you want of the thesis itself, but look at the pie charts p29 30 31. I find it to be one of the best example of sighted bias and why cognitive dissonance is such a real thing in everybody's life.
the number of subjects isn't really significant so I wouldn't use it to "prove" that DSD sounds like PCM, but it's still in accordance with most trials on the subject. but in a world were people go pay 1000$ for a headphone cable, it's not so strange to still see people going all Don Quixote against PCM.