DirectStream - do I dare suggest a FW revision?


#1

Yes, I think I do. Now that my DS has 400 or so hours on it, I don’t think it’s going to do anything beyond what it’s doing now. You’ve seen in the First Impressions thread that I went so far as to rebuild my PWD to make sure of what I thought. While the DS is overall a better DAC than the PWD, I’m not so sure I’d go so far as to say there is nothing to examine. While the PWD may have been surpassed by the DS, the PWD’s shortcomings were integrated into the fabric of the DAC - nothing called attention to itself as an obvious flaw. It wasn’t until you stacked it up against the DS or another higher end DAC that IME you’d walk away going “yeah, the PWD may not be quite as good”. The DS on the shelf is a $6K DAC; IMO it should have no “noticeable” shortcomings - the kind that call attention to themselves.

I spent a lot of time listening to my PWD, other DACs in my and other systems, my own TT, and other TTs in other systems. I’m sure most of us have done all these things, and I’m sure Paul and Ted have as well. I’m using this experience as a “consensus driver” on what I think are common characteristics in music that I use when try to get a bead on a system. One can argue with me about the merits of this method, but it’s my method and I think it tells me something about what… sounds right.

If there is going to be a firmware revision at some point, I think there are two areas that should be addressed as part of that effort: the harshness in the upper mids and the “low end drive”.

I referred to harshness in the upper mids as “glassines”. The fact that near everyone has a number of DS users have* heard it - in vastly different systems - suggests it is a characteristic of the DAC that is calling attention to itself. It’s better but still there after 400 hours; I don’t think it’s going to go away. I normally use silver ICs. I’ve tried a couple of different copper types (to eliminate the possibility of “that silver sound”) to no significant change. I’ve even changed power cords. Again small changes, not enough to really matter for a DAC at this level. I originally concluded that the improved clarity of the DS was probably just giving us what was on the recording, but I’m not so sure about that right now.

So a question Ted: why are so many of us hearing this? What is it about the DS that seems to play into what we’re hearing?

The second area is what I called “low end drive”. Like Elk, I briefly thought the DS didn’t go as low as (in my case) the PWD. It does, but it also brings clarity and articulation the PWD didn’t have to the same degree. This may be a case of “you get one thing, you pay for it with something else”, or not. When I listened to a lot of music through the PWD, and through my TT and through other “audiophile” systems, the low end typically creates a strong underpinning to the music. Listen to “Bluesville” on “88 Basie Street”. On many good systems the double bass and the other low frequency instruments create a continuous, persistent undercurrent that brings the rest of the music with it. This is how live jazz sounds, IME. I don’t get the same sense of “foundation” through the DS. The DS goes as low, I’m pretty sure, but it doesn’t seem to lay that down in a way that makes the rest of the music sound “driven” by it.

We know the PWD went through many changes in sound as the FW kept evolving. We’ve all read that the DS should not (hopefully) be as unpredictable with respect to any FW changes it might get. It’s my own opinion that I think these two areas should be looked at for any upcoming release. I know this is a slippery slope - we all want the DS to be properly engineered in both HW and FW. We don’t want it purposely “voiced”. By the same token there is plenty of superbly engineered audio gear that does not deliver the musical goods. I am not saying the DS is one of these components. I think what I’m saying is the DS does so many things so very well, that anything that is not consistent with all that goodness gets noticed.

(* edited after concurrence with woot’s observation)


#2

I wonder if the glassy upper mids is extra pronounced on point sources?

So far I have not experienced it on my ribbon foil. What I experience is increased speed and clarity but without anemic or digital glare.

Maybe lack of distortion and immediacy sometimes comes disquised as aggression…(?)

To me the PWD maybe is voiced a bit more romantic sounding and fuller/ingratiating. The DS sounds more tight.

The sound on the PWD also appear a bit more fluffy/muffled.

Also, I have not found the missing decay problem, but I would not say that the DS excel on all parameters.

I wouldn’t say the DS on purpose is voiced to be impressive on an immediate basis either.


#3

Interesting note about point source speakers. That hadn’t occurred to me.

Frode said

Maybe lack of distortion and immediacy sometimes comes disquised as aggression…(?)

Could be, but I don't recall hearing this quality to the same degree through a dCS Vivaldi stack, through Scaena speakers, or on a number of other systems of similar nature.
Frode said

To me the PWD maybe is voiced a bit more romantic sounding and fuller/ingratiating. The DS sounds more tight.

I would agree with that. I think my observations are not so much about the quality of the sound (fuller versus more accurate), but more about what seem (to me) like things that are not quite in line with the rest of the picture (so to speak).
Frode said

The sound on the PWD also appear a bit more fluffy/muffled.

Yes, I agree with that as well.

#4
tony22 said Yes, I think I do. Now that my DS has 400 or so hours on it, I don't think it's going to do anything beyond what it's doing now. You've seen in the First Impressions thread that I went so far as to rebuild my PWD to make sure of what I thought. While the DS is overall a better DAC than the PWD, I'm not so sure I'd go so far as to say there is nothing to examine. While the PWD may have been surpassed by the DS, the PWD's shortcomings were integrated into the fabric of the DAC - nothing called attention to itself as an obvious flaw. It wasn't until you stacked it up against the DS or another higher end DAC that IME you'd walk away going "yeah, the PWD may not be quite as good". The DS on the shelf is a $6K DAC; IMO it should have no "noticeable" shortcomings - the kind that call attention to themselves.

I spent a lot of time listening to my PWD, other DACs in my and other systems, my own TT, and other TTs in other systems. I’m sure most of us have done all these things, and I’m sure Paul and Ted have as well. I’m using this experience as a “consensus driver” on what I think are common characteristics in music that I use when try to get a bead on a system. One can argue with me about the merits of this method, but it’s my method and I think it tells me something about what… sounds right.

If there is going to be a firmware revision at some point, I think there are two areas that should be addressed as part of that effort: the harshness in the upper mids and the “low end drive”.

I referred to harshness in the upper mids as “glassines”. The fact that near everyone has heard it - in vastly different systems - suggests it is a characteristic of the DAC that is calling attention to itself. It’s better but still there after 400 hours; I don’t think it’s going to go away. I normally use silver ICs. I’ve tried a couple of different copper types (to eliminate the possibility of “that silver sound”) to no significant change. I’ve even changed power cords. Again small changes, not enough to really matter for a DAC at this level. I originally concluded that the improved clarity of the DS was probably just giving us what was on the recording, but I’m not so sure about that right now.

So a question Ted: why are so many of us hearing this? What is it about the DS that seems to play into what we’re hearing?

The second area is what I called “low end drive”. Like Elk, I briefly thought the DS didn’t go as low as (in my case) the PWD. It does, but it also brings clarity and articulation the PWD didn’t have to the same degree. This may be a case of “you get one thing, you pay for it with something else”, or not. When I listened to a lot of music through the PWD, and through my TT and through other “audiophile” systems, the low end typically creates a strong underpinning to the music. Listen to “Bluesville” on “88 Basie Street”. On many good systems the double bass and the other low frequency instruments create a continuous, persistent undercurrent that brings the rest of the music with it. This is how live jazz sounds, IME. I don’t get the same sense of “foundation” through the DS. The DS goes as low, I’m pretty sure, but it doesn’t seem to lay that down in a way that makes the rest of the music sound “driven” by it.

We know the PWD went through many changes in sound as the FW kept evolving. We’ve all read that the DS should not (hopefully) be as unpredictable with respect to any FW changes it might get. It’s my own opinion that I think these two areas should be looked at for any upcoming release. I know this is a slippery slope - we all want the DS to be properly engineered in both HW and FW. We don’t want it purposely “voiced”. By the same token there is plenty of superbly engineered audio gear that does not deliver the musical goods. I am not saying the DS is one of these components. I think what I’m saying is the DS does so many things so very well, that anything that is not consistent with all that goodness gets noticed.


Seem to me SOME are hearing this, not most, and MOST of the some are saying it is dissipating with break-in. I use silver cable both in IC’s and speaker cable and have not had this issue. As far as bass, I’ve had to turn my powered woofers down a bit. The bass, to my ears, is well defined and balanced.

#5

A tough call.

If I were responsible for voicing the unit, I would wait.

At least for me, the hardness in the treble is very slight and I would be concerned with doing more harm then good. I also do not know what it is. I am certain the frequency response is flatter than what any of us can hear. I am not yet convinced the impression is not psychosomatic in a sense; that my characterization is based on a misapprehension/lack of familiarity with the sound.

I do not find the bass lacking. It did take me a little bit to appreciate the sound was cleaner and more textured, not bass restrained. I appreciate the delicacy of the highs.

The timing is exquisite.

I believe Frode is correct; the sound is not one to beat one over the head and immediately overwhelm. I am going to try his suggestion and try the DS on speakers I have with Heil folded ribbon tweeters.


#6
Elk said A tough call.

If I were responsible for voicing the unit, I would wait.

At least for me, the hardness in the treble is very slight and I would be concerned with doing more harm then good. I also do not know what it is. I am certain the frequency response is flatter than what any of us can hear. I am not yet convinced the impression is not psychosomatic in a sense; that my characterization is based on a misapprehension/lack of familiarity with the sound.

I do not find the bass lacking. It did take me a little bit to appreciate the sound was cleaner and more textured, not bass restrained. I appreciate the delicacy of the highs.

The timing is exquisite.

I believe Frode is correct; the sound is not one to beat one over the head and immediately overwhelm. I am going to try his suggestion and try the DS on speakers I have with Heil folded ribbon tweeters.


Just to be clear, Elk.

I fully respect your findings.

You are probably the one herein with the best experience in listening for the natural instrument timbres, etc.


#7
woot said

Seem to me SOME are hearing this, not most, and MOST of the some are saying it is dissipating with break-in.

Yes, my apologies for that. In my haste to get this post out before dinner I didn't look it over carefully enough before letting it go. Perhaps it might be more accurate to say a number of people seem to be identifying similar sorts of things.
Elk said

At least for me, the hardness in the treble is very slight and I would be concerned with doing more harm then good. I also do not know what it is.

I can understand that. As well, all of this could just be part of integrating a new component into a system. Tuning can take some time. I went through 4 power cords and 3 pairs of ICs before I found the right combination for the PWD. I have a couple of other ICs on the way from some friends.
Frode said

Just to be clear, Elk.

I fully respect your findings.

You are probably the one herein with the best experience in listening for the natural instrument timbres, etc.

+1. I also value Elk's assessment of things audio.

#8

embarassed


#9

Elk, when the blood rushes back to your brain, give us all that assessment of the DS we’ve been waiting for!21_gifbeer_gif


#10

Howdy all

I’ve started to post a reply to this thread three times, maybe I’ll get to the end of this one.

I do take everyone’s “complaints” and recommendations seriously.

I am actively thinking and testing hypotheses about things in the design that could cause people’s experiences, even if I’m not sure they are typical of the average user. If anything can inspire or goose me into finding and fixing a bug that will make anything more technically correct I’m all for it.

For example before the DS was released Paul kept bugging me about the bass. I hemmed and hawed and finally thought I figured out what was wrong, got four inner traces cut with a NC drill machine and nothing changed :slight_smile: I then found some bias resistors that were too large. We made them smaller in stages trying to find the point of diminishing returns between smaller and smaller improvements in the bass and larger and larger demands on the power supply. We went a little past the point of audible improvement and I’m happy. Were all better off because Paul kept bugging me.

Since the release I haven’t found a magic bullet that makes everything better for everybody but I’m still looking :)

-Ted


#11
Ted Smith said

I am actively thinking and testing hypotheses about things in the design that could cause people’s experiences, even if I’m not sure they are typical of the average user. If anything can inspire or goose me into finding and fixing a bug that will make anything more technically correct I’m all for it.

Thank you Ted. I'm glad my comments were taken as observations are questions (which they are) and not as rock throwing. And I do like that you are keeping the engineering rigor in the equation. I know there's a bit of magic in making a great sounding piece of audio gear, but IMO it's too hard to do if real engineering is considered "optional".smile
Ted Smith said

For example before the DS was released Paul kept bugging me about the bass. I hemmed and hawed and finally thought I figured out what was wrong, got four inner traces cut with a NC drill machine and nothing changed :slight_smile: I then found some bias resistors that were too large. We made them smaller in stages trying to find the point of diminishing returns between smaller and smaller improvements in the bass and larger and larger demands on the power supply.

I'm curious. What change did this bring?

#12
tony22 said
Ted Smith said

For example before the DS was released Paul kept bugging me about the bass. I hemmed and hawed and finally thought I figured out what was wrong, got four inner traces cut with a NC drill machine and nothing changed :slight_smile: I then found some bias resistors that were too large. We made them smaller in stages trying to find the point of diminishing returns between smaller and smaller improvements in the bass and larger and larger demands on the power supply.

I’m curious. What change did this bring?


I knew someone would ask :)

The bass wasn’t quite right and it wasn’t obvious that there was a problem for a while. Since I couldn’t think of anything frequency response related from, say 5Hz to 100Hz except possibly something in the transformer, I was standing firm that things were fine. Then PS Audio found a ridiculous amount of distortion down around 20Hz. That meant I had something to work on. It turned out that some bias resistors were 10k which was fine on the prototype but not so good in the current design - as we lowered the value to 1k that lowered the point the distortion was showing up in proportion. Lowering them to 499 Ohms didn’t cause any significant heating or anything and the base got much richer - the body of cellos, string basses, etc. bloomed (without becoming flabby). Correct bass supports the whole rest of the spectrum and on some material I’d swear it was fixing things at the top of the orchestra as well.


#13

Okay. So bear with me Ted. Assuming there are a few of us who are hearing this hardness or glassiness in the upper mids - what could it possibly suggest?


#14
tony22 said Okay. So bear with me Ted. Assuming there are a few of us who are hearing this hardness or glassiness in the upper mids - what could it possibly suggest?
Hardness, especially in the upper frequencies, always brings aliasing to mind. To my ear jitter also can cause a brittleness up high. Component choices also come to mind.

On the bug front I’ve been checking things out like a digital filter with too few bits somewhere or bogus coefficients. Similarly in the sigma delta modulator: is there a bug or some design parameter I mistuned?

Coincidentally I’d already dedicated this long weekend as a time specifically to look for possible problems that could cause the issue at hand - I’ve yet again double checked most of the design and possible problems listed above. Also some ad hoc experiments haven’t yielded any tunable parameters that affect this issue.

Without enumerating all of the things I’ve done I’m still working on it explicitly this weekend and will be keeping it in mind down the road and will put aside time now and then just for these SQ kind of issues.


#15

Go engineer, go!happy-048_gif


#16
Ted Smith said

I do take everyone’s “complaints” and recommendations seriously.

. . . and the base got much richer – the body of cellos, string basses, etc. bloomed (without becoming flabby). Correct bass supports the whole rest of the spectrum and on some material I’d swear it was fixing things at the top of the orchestra as well.


Ted, it is obvious that you take every comment question extremely seriously. That you are able to do with such openness and respond non-defensively demonstrates great strength of character. This has got be intimately personal for you. It would be exceedingly difficult for most of us to maintain an open mind as you do. Kudos.

I adore the story about the bass. I am very pleased with the sound in this regard, the texture and timbre is spectacular. You removed the muck of the PWD and the vast majority of other DACs. So much so, I initially thought a bit of weight was missing. I was wrong.

I also fully agree getting the bass right fixes the top end. Not only is the bass typically the most important line, especially in classical music, the entire orchestra sits on the bass as the foundation. It could not be more important. You nailed it.


#17

I really hope any remedy will be software related (firmware upgrade).


#18

As ELK said “The timing is exquisite.”

This, to me, was immediately evident and proved to be one of the most important conversations during the firmware marathon.

There were obvious changes with every software adjustment and as the user interface controls were activated and refined. Even with the PWD experience, I was blown away by magnitude of the effects. I think the DS is so much better at revealing the finer details that they present and, easier to pick out.

Even without any discussion of burn in improvement, the ability of the DS to look “inside” the “bubbles” that enveloped the sound was outstanding and immediately appealing.

The PWD was not veiled with a curtain like effect, more like a very thin and transparent gelatin capsule delivering the tones. Almost like I could hear the ethernet “packets” that delivered them.[just an attempted example]

This capsule seemed to add it’s own tonal quality and probably was one of the reasons that preferences varied with the PWD firmwares. 2.0.2 seemed “smoother” but, for some, it lacked tempo and dynamics. 2.2.0 had more “git up n go” dynamics, but for some, was “aggressive” sounding.

With the DS you get inside TO the actual voice or instrument and, to me, this supports enhanced involvement with the performers and performance. This is why I found this to be initially distracting from previous qualities like stage etc. The timing, again, sounds “right”. My only concern, in my rig, was a slight congestion in the lower treble that was ONLY evident during complicated passages and voice bridges where amplitude changes occurred. If I listen for it specifically and hand pick the tracks that accentuate it, then I do recognize a slight lack of timbre there but really only if it is high on my radar.

My personal preference is to have ample “meat on the bones” as , for me, this can translate to richness of tone. The PWD accomplished this by adding a quality of it’s own to the sound[capsule] but was IMHO less faithful to the original recording. The DS has proven that we can indeed break that barrier and go much deeper.

In fairness, I think we need to have more 4-500 hour DSs out there to fully understand the effects that the many system variables and personal preferences have on future development.

As we all can see, Ted is on top of the comments and dedicated to the continuing development of this, already, 10 year project. We also need to continue to analyze our own rigs as well since the substitution of the DS for our previous DAC[s] opens a whole new Pandora’s Box of personal tuning preferences. Any change in timing and transparency could very possibly mask the magic that the DS brings to us.

I have no doubt that both intended as well as unintended changes will occur during further development and that the Beta team will be back at it before too long.


#19
gordon said My only concern, in my rig, was a slight congestion in the lower treble that was ONLY evident during complicated passages and voice bridges where amplitude changes occurred. If I listen for it specifically and hand pick the tracks that accentuate it, then I do recognize a slight lack of timbre there but really only if it is high on my radar.
Do you think this is the same slight glassiness/hardness some of us hear?

I do not hear any congestion (at least I do not believe I do), but your description of lack of timbre fits. Additionally, a deficit of timbrel detail could make it more difficult to parse the underlying music, resulting in a sense of congestion.

My spidey sense suspects we are describing the same thing in different ways.

Tony?


#20

The link below, although perhaps not perfect, might serve as a helpful reference. I just googled for it now.

When I referred to “congested” it seemed like the air and transparency was less than at other frequencies [ even higher ones]. so like 3 horns [example] sounded like one. This stood out more especially when compared to the amazing separation during other passages.

As my DS “opened” up this became much less and I think the “glassiness” described was more the lack of transparency rather than an anomaly at 6khrz. One of my earliest posts was that even a rough edged recording seemed more palatable due to the added airyness and transparency of the DS. The ability to see/hear into the notes made everything sound less “hi-fi” produced and that is what spawned the 4 letter R word, for lack of a better de facto term.

GLOSSERY:

http://www.head-fi.org/a/describing-sound-a-glossary