[Christer]

The only thing I have to say on the subject is;

At it's worst, my nerves could physically feel audio from the tv or my speakers in the living room.

I schit you not, all I had to do was stick my feet up and aim them at the tv and deep bassy type noises would register and make my feet feel like they were standing on top of a speaker, like that dude in the movie, "it's all gone pete tong". My feet could feel the beat from the other side of the room and not just bass, the soles of my feet would feel like it was rippling and I could feel them change with different frequencies, it was nuts. Tv was slightly louder than normal.

Then it started happening in my hands, but not so bad, and now I'm left with a permanently gimped left thumb, if I touch the underside of my left thumb, I feel it on my left big toe, it's like somebody tickling my big toe, it's weird as schit, but, on the bright side, if I ever have an itchy toe, I just need to rub my thumb.

Im positive that if a bat was in the room with me then and it was in the dark, I'm sure my feet radar would of detected it's ultrasonic squeaks.


As for the real topic, I think that although 20khz is max for the best human ears on the planet ( young kids only, and even then it would probably be a low percentage of them that could hear 20khz ) to phsyically hear.

However, I do think that it is possible that ultrasonic sound has some influence, the same with the other end of the spectrum, infrasonic. Nobody can hear better than 20khz, but I do think infra and ultrasonic frequencies have some influence on us/brain, even though we physically cant hear them.

I bet that if someone were to do eeg's, ct scan's and mri scans with contrast and play normal music, and then play the same tracks but this time ultrasonic and infrasonic tones added, or even just scan them with no music, and then send both those tones down the headset to them without telling them they were doing it. I'm sure the results would show activity in certain parts of the brain that wasn't showing activity before both frequencies were played.

I would put money on that being true, as our brain is highly under utilised and alot of things happen to us subconciously and we just don't know about it.

Thats what I think regarding the topic, and I thought I would share a funny anecdote.

Hmm, I am not sure how some what you say above actually relates to the topic here?

But I can also remember from old days of FM Radio that it sometimes helped curing weird disturbances in Radio reception if I just touched the antenna on my little radio as a teen.
Reception improved instantly.
And if I removed my hand from the antenna the disturbances would return.
Sometimes I had to keep my hand firmly on the antenna for long periods of time to listen without disturbances.
And RF or whatever can sometimes cause dropouts if my HD800 cable is too close to my M Scaler was not unknown even in the days of LP.
My headphone cable to my Jecklin Floats was so radiophonic that for a while I had a friend of mine think I was a really telepathic, simply by telling him what he had just been talking about on his comradio in his car minutes before he came to visit me.
Cheers CC.

 

[tekkster]

Hmm, let me once again reveal my ignorance of tech terms. I have seen the term slew rate before,mainly in specs for amps I think?
But what exactly is it?

And why would it matter with dacs?

And while I am at it and in view of what Rob just replied regarding ringing the Gibbs phenomenon, and similar wasn't one of the main claims for DSD that it does not "ring" as PCM?

I vaguely remember seeing similar impulse pics comparing PCM and DSD where PCM showed ringing and the DSD did not. In my ignorance I did of course think that DSD would have better and cleaner transients than PCM with those shots as indications and evidence of that?
And one of the engineers I know used to claim transients with DSD as being closer to how he heard things live than with pcm, while another one claimed the opposite!
But if I now understand Rob correctly that is not true at all, the way he filters pcm?

And also,no matter how high you go with DSD you still have the fundamental limitations of the format?

So the new DAC from the German company T+A standing for "theory and practice" in German, which now claims to do both DSD 1024 and 3 billion computations per sec in their latest flagship, would still suffer the same basic limitations as any DSD dac?

But would not actually sound better or more resolving than say a Qutest on its own in purely technical terms if I understand Rob correctly?

But they still charge 26 K USD for it obviously? The Qutest sells for under 2k USD doesn't it?

And there is another native 1 bit DSD DAC just reviewed over at CA/AS that apparently costs 45K USD!

And I used to think Chord products were overpriced!

Maybe I will have to re-access my take on pricing a bit, in view of what I keep hearing via HMS and what Rob claims and what HMS costs?
Cheers CC.

This is really just interesting to me, and I'm not sure there is a major effect.

Way back, decades ago, when I was more into analog audio and speakers, slew rate was a common topic, but to some extent I imagine it applies today.

Slew rate is just how fast voltage measurement changes occur, which is a fun number for me to just want to know. Generally measured in volts over microsecond.

It's not exactly related to the DAC. But it kind of is. It's not about the digital side, and it's not exactly about the conversion part, but it is about the resulting, post conversion voltage instructions over time. The DAC delivers those instructions to the Amp, the Amp amplifies them, and sends them over the headphone cable to the driver, which then has to positively and negatively move based on the voltage instructions. Back in the 80's when I was in highschool, it was a topic for amps, because the steeper the slew rate, and the more accurately the amp (which amplifies the resulting analog voltage commands from the DAC) can get from 0 voltage to the designated voltage, supposedly the better transients were. I remember slew rate being a big deal discussion topic back then. Even back then though, it was only on the DIY op amp kits where I noticed differences. The higher end gear we sometimes got to play around with were already so good as to make the discussion kind of moot.


Maybe that still applies today, maybe gear has gotten so good that it's not a number anyone cares about anymore.

Really just a little nostalgic for me, since I remember my friends and I being really into that over 30 years ago as a teenager. And interestingly, maybe because it's a moot point now, slew rates don't show up in measurements of DACs and DAC/amps. So, I'm really kind of curious, and don't believe, necessarily, that there are enough differences in slew rates in today's products to even really matter.

It might....but for me, it's just a fun little thing to do. And c'mon, isn't it just fun to have an oscillator on your desk measuring square waves and seeing how different DACs and DAC/amps respond?

All I need is the movie Weird Science playing in the background, next to the oscillator, and I'm a teenager again (^-^)

 

[Christer]

This is really just interesting to me, and I'm not sure there is a major effect.

Way back, decades ago, when I was more into analog audio and speakers, slew rate was a common topic, but to some extent I imagine it applies today.

Slew rate is just how fast voltage measurement changes occur, which is a fun number for me to just want to know. Generally measured in volts over microsecond.

It's not exactly related to the DAC. But it kind of is. It's not about the digital side, and it's not exactly about the conversion part, but it is about the resulting, post conversion voltage instructions over time.

Back in the 80's when I was in highschool, it was a topic for amps, because the steeper the slew rate, and the more accurately the amp (which amplifies the resulting analog voltage commands from the DAC) can get from 0 voltage to the designated voltage, supposedly the better transients were.

Maybe that still applies today, maybe gear has gotten so good that it's not a number anyone cares about anymore.

Really just a little nostalgic for me, since I remember my friends and I being really into that over 30 years ago as a teenager. And interestingly, maybe because it's a moot point now, slew rates don't show up in measurements of DACs and DAC/amps. So, I'm really kind of curious, and don't believe, necessarily, that there are enough differences in slew rates in today's products to even really matter.

It might....but for me, it's just a fun little thing to do. And c'mon, isn't it just fun to have an oscillator on your desk measuring square waves and seeing how different DACs and DAC/amps respond?

All I need is the movie Weird Science playing in the background, next to the oscillator, and I'm a teenager again (^-^)

Yes I remember it better now that you say so. When I also built some amps in my teens that is when slew rate was often mentioned in specs.
Enjoy your teen flashback.
And who knows ? Maybe it still matters?
Cheers CC

 

[analogmusic]

Digital playback weakness always been transients ...

 

[Chester Rockwell]

what filter on H2/tt2/qutex with m scaler are people using, white or green and why ?

I’ve been using the green filter as I assume the 705/768 file generated by the M Scaler benefits from filtering like standard hi-res files do.

 

[schnesim]

And also,no matter how high you go with DSD you still have the fundamental limitations of the format?

IIRC Ted Smith said, that in order to overcome the issues of DSD they upsample the signal 20x in order to push the noise way out of the audible range.
Seems viable to me...

 

[Christer]

IIRC Ted Smith said, that in order to overcome the issues of DSD they upsample the signal 20x in order to push the noise way out of the audible range.
Seems viable to me...

Hello, yes I am aware of that too.

But isn't that what Rob has been doing too for quite a while?

With my limited tech knowledge I don't know how much he upsamples the signal compared to Ted Smith though?
But according to Rob upsampling DSD is not enough. According to him and what I sometimes hear comparing at least DSD 64 against HI RES PCM there are other issues too.

Warm,sweet ,nice and,analogue like,as DSD can sound at its best it still tends to sound a bit lacking in resolution to me compared to the very best of PCM.

But as I have said before, I never hear any of the hardness that can sometimes make even some hi res pcm less enjoyable than DSD.

Cheers CC

 

[dmance]

Hello, yes I am aware of that too.

But isn't that what Rob has been doing too for quite a while?

With my limited tech knowledge I don't know how much he upsamples the signal compared to Ted Smith though?
But according to Rob upsampling DSD is not enough. According to him and what I sometimes hear comparing at least DSD 64 against HI RES PCM there are other issues too.

Warm,sweet ,nice and,analogue like,as DSD can sound at its best it still tends to sound a bit lacking in resolution to me compared to the very best of PCM.

But as I have said before, I never hear any of the hardness that can sometimes make even some hi res pcm less enjoyable than DSD.

Cheers CC

With my highly resolving and RF noise-free loudspeaker system: voxativs, AC isolated REL subwoofer, optical isolation on DX, HMS on batteries, etc, - my distinction between DSD and PCM is simply that PCM brings in a much more compellingly real soundstage than DSD. There is also a certain effortlessness to PCM listening sessions vs DSD. Now, I have no certainty of the provenance of my recordings but regardless, there is some solid truth in what Rob says that the inherent noise in DSD-based playback, no matter how high you push it up in freq, affects the ear/brain's ability to accept it as reality.

 

[mlxx]

And also,no matter how high you go with DSD you still have the fundamental limitations of the format?

So the new DAC from the German company T+A standing for "theory and practice" in German, which now claims to do both DSD 1024 and 3 billion computations per sec in their latest flagship, would still suffer the same basic limitations as any DSD dac?

Check out this excellent video...

It's long and a bit technical but explains some of the digital magic.
Keep in mind that 1 bit DSM is what Sony branded as DSD, multi bit DSM which is a lot better is no longer DSD.

Also a post from Rob about different DSD rates.
https://www.head-fi.org/threads/chord-electronics-dave.766517/page-741#post-14220496

 

[514077]

IIRC Ted Smith said, that in order to overcome the issues of DSD they upsample the signal 20x in order to push the noise way out of the audible range.
Seems viable to me...

But then, they bring the final output back down to DSD128. So, even if you have something in 256, it does you no good. I never understood that. (Unless I'm wrong)

 

[514077]

Check out this excellent video...

It's long and a bit technical but explains some of the digital magic.
Keep in mind that 1 bit DSM is what Sony branded as DSD, multi bit DSM which is a lot better is no longer DSD.

Also a post from Rob about different DSD rates.
https://www.head-fi.org/threads/chord-electronics-dave.766517/page-741#post-14220496

The more I read Rob's posts on DSD, the more I'm slowly beginning to understand what's wrong with it. I'm not a digital engineer by many means, so I have to be hit over the head a few times for it to sink in. I still like to listen to Paul' McGowan's podcasts, but I've not risked buying one of his DSD-based DACS. I think he likes DSD for its analogue qualitys: he refers to DSD as analogue. And I've obviously chosen Rob's technology over PS.
However, in the long run, it still depends on each choice of content. I like some DSD, still.

 

[dmance]

The more I read Rob's posts on DSD, the more I'm slowly beginning to understand what's wrong with it. I'm not a digital engineer by many means, so I have to be hit over the head a few times for it to sink in. I still like to listen to Paul' McGowan's podcasts, but I've not risked buying one of his DSD-based DACS. I think he likes DSD for its analogue qualitys: he refers to DSD as analogue. And I've obviously chosen Rob's technology over PS.
However, in the long run, it still depends on each choice of content. I like some DSD, still.

UE, PSAudio DACs use a high frequency multibit internal stage ... similar to all DACs. Rob's DACs directly modulate the output from the multi bit stream whereas Ted brings everything down to a single bit stream for simple low pass filtering. Both sound good and there are arguments both way for which is technically best. I much prefer Rob's approach.
I think Ted's new $25k TSS DAC would be a more fair comparison with Rob's M stack. Ideally an optical link for DX would provide the same benefit as Ted's two box design for a fraction of the cost.

 

[Deftone]

There is no dedicated headphone amp but headphones could be driven from the TSS outputs but not intended to work well with all headphones this way.

I think the dCS bartok (£12,000) is much more closer in price as Dave + Mscaler (£13,000) TSS will be $25,000+

 

[Christer]

The more I read Rob's posts on DSD, the more I'm slowly beginning to understand what's wrong with it. I'm not a digital engineer by many means, so I have to be hit over the head a few times for it to sink in. I still like to listen to Paul' McGowan's podcasts, but I've not risked buying one of his DSD-based DACS. I think he likes DSD for its analogue qualitys: he refers to DSD as analogue. And I've obviously chosen Rob's technology over PS.
However, in the long run, it still depends on each choice of content. I like some DSD, still.

Hello UElong,
It seems we are maybe "in the same boat" regarding the tech and spec bits,you and me.
I also need to regurgitate the "tech bits" and chew them a few times,before they sink in.
My tech knowledge is VERY limited.

But I also have to add that especially since getting the M Scaler,although DSD SQ also benefits from it, compared to my Chord DACs on their own ,I more and more also HEAR what Rob says when comparing SQ between DSD and HI RES PCM.

What raised my interest a bit again regarding the old DSD/PCM debate, was the review over at formerly CA now /AS of the new APL DSD DAC.
And particularly where the reviewer heard how this VERY expensive, 45k USD! DSD DAC tended to clump together instruments with a 176.4 PCM recording of very complex, very densely scored music.

The piece which I know quite well, was the Passacaglia from a work by Benjamin Britten.

A stunning piece musically, but also very good material to compare how different links in a reproduction chain can influence and colour the end result.

Judging from what I hear more and more from HMS, this short but imho maybe MOST telling paragraph in the review made me suspect that as Rob keeps stating over and over again,the inherent format limitations of DSD could be the main cause of the lumping together of instruments that the reviewer heard in his system from this recording?

Much as I really like some of my DSD 64 albums musically, they don't seem to dig quite as deep into the VERY VERY low level inner details as my best HI RES PCM albums.

But at the same time I have to admit that sometimes at concerts,my first thought can still occasionally be, WOW, those wonderfully mellow and warm strings sound more like DSD than PCM to me.

THE good thing about even the Sony/Philips orginal 1 bit DSD 64 imho,is that it never sounds as hard as PCM sometimes does,especially 16/44.1.
And neither does live acoustic music in most halls.

Although there are some exceptions there as well in my experience. Both Berwaldhallen in Stockholm and Rudolfinum in Prague can sound a bit abrasive and hard with some music and from some seats in those halls.

And the good thing for me with the M Scaler and Rob's current approach and handling DSD it seems to retain "the good bits" pun intended, while adding a bit more resolution and space, and getting rid of most of the noise.
But I still tend to hear a slightly higher noise floor with DSD than with my best PCM albums.
I think Rob once said the way he does DSD he gets "the best of two worlds" didn't he?
Finally, before analogmusic gets me again....
Ho Hum... And let's just enjoy the music...
Cheers CC

 

[514077]

Hello UElong,
It seems we are maybe "in the same boat" regarding the tech and spec bits,you and me.
I also need to regurgitate the "tech bits" and chew them a few times,before they sink in.
My tech knowledge is VERY limited.

But I also have to add that especially since getting the M Scaler,although DSD SQ also benefits from it, compared to my Chord DACs on their own ,I more and more also HEAR what Rob says when comparing SQ between DSD and HI RES PCM.

What raised my interest a bit again regarding the old DSD/PCM debate, was the review over at formerly CA now /AS of the new APL DSD DAC.
And particularly where the reviewer heard how this VERY expensive, 45k USD! DSD DAC tended to clump together instruments with a 176.4 PCM recording of very complex, very densely scored music.

The piece which I know quite well, was the Passacaglia from a work by Benjamin Britten.

A stunning piece musically, but also very good material to compare how different links in a reproduction chain can influence and colour the end result.

Judging from what I hear more and more from HMS, this short but imho maybe MOST telling paragraph in the review made me suspect that as Rob keeps stating over and over again,the inherent format limitations of DSD could be the main cause of the clumping together of instruments that the reviewer heard in his system from this recording?

Much as I really like some of my DSD 64 albums musically, they don't seem to dig quite as deep into the VERY VERY low level inner details as my best HI RES PCM albums.

But at the same time I have to admit that sometimes at concerts,my first thought can still occasionally be, WOW, those wonderfully mellow and warm strings sound more like DSD than PCM to me.

THE good thing about even the Sony/Philips orginal 1 bit DSD 64 imho,is that it never sounds as hard as PCM sometimes does,especially 16/44.1.
And neither does live acoustic music in most halls.

Although there are some exceptions there as well in my experience. Both Berwaldhallen in Stockholm and Rudolfinum in Prague can sound a bit abrasive and hard with some music and from some seats in those halls.

And the good thing for me with the M Scaler and Rob's current approach and handling DSD it seems to retain "the good bits" pun intended, while adding a bit more resolution and space, and getting rid of most of the noise.
But I still tend to hear a slightly higher noise floor with DSD than with my best PCM albums.
I think Rob once said the way he does DSD he gets "the best of two worlds" didn't he?
Finally, before analogmusic gets me again....
Ho Hum... And let's just enjoy the music...
Cheers CC

Enjoying the music is credo. Would you happen to have a link to that review? I like reading reviews if only for relaxation.