NOS vs. OS DACs-My Take
Jan 12, 2009 17:47:12 GMT
Post by rickcr42 on Jan 12, 2009 17:47:12 GMT
The below is an opinion,my own,and as such reflects my personal journey with trying to get my sampled audio (digital) to sound as good "overall" as my un-sampled audio (analog) and I have to say it has been a long road and is still one not totally resolved.
On paper there is no contest in linearity,bass extension or dynamic range but in the time/phase realm ?
You woud be hard pressed to even find this spec mentioned other than in either a cryptic fashion or to tout some "new trick" circuitry used to separate one manufacturer's product from another's which you really need to take with a grain of salt mostly these fancily named circuits usually just a variation on what everyone else is offering- (no new "wheels" invented here mostly,just ad copy saying it was so
)
Funny thing is,if you go ONLY by the raw data-the "spec" one would if they are to be beleived really start to question what they hear because there is a disconnect between the information and the reality of listening that mostly is so wide one would think either one side is delusional or the other flat out lying and the "WAR" is and has been raging for decades.So what is the truth of things ? What does the listening say that the data sheets do not ?
For one,that we can recover rapidly from small "warts" that occur over a very short time (pops/ticks) or that do not take away from the music even is ever present (low level hiss/noise) AS LONG AS the music draws you deeper into the actual performance because it is so emotionally "correct" that it grabs you-much like audience noise or the odd firecracker at a rock concert not taking away from a live musical event.
what we can NOT disregard is when the entire musical session is flawed or that no matter how hard you try you look to the person next to you and say "can't put my finger on it man but something is just not right here man.The drummer is out of sync or the guitars are a tad late or the singer is missing his marks but SOMETHING IS WRONG HERE.That or maybe like having a crap seat in a venue not known to have great acoustics or if it does,onely in a few slected sweet spots or maybe if an outdoor venue one where you find yourself in an "echo" chamber and you have to move around until you find the "null".These constants totally ruin what could have been a good experience but that in the end leave one wondering why the hell they bothered (been to some damn bad live events in my time and I have to say I usualy left pissed
)
anyway.Here is how I translte the above into the domestic music playback experience with digital as the main topic and "sampling" as the sub topic.
Again,these are my findings based on many years of listening and remeber-when the CDP first came out:
1-ALL were 14 Bit NOS based because there were no digital filters yet
2-There WAS NO SPDIF stream other than for data testing because there were NO external DACs yet so jitter was not the problem it is now
3-ALL anti-aliasing filters SUCKED in the beginning being extremely steep brick wall filters in order to keep the aliasing out of the audible signal and why the oversampling digital filter was invented to begin with
4-Once designed then implemented It mostly didn't help the analog stages anyway the actual build sucking so bad
5-There was not a whole lot you cold do about it there being not many options to choose from (for example op-amps,quality passive parts,etc)
So you pretty much bought the machine and lived with pretty damn bad sound but that you could take to the car,play in a "walkman" or boom box and in the end get sound that was better than other alternatives plus once Columbia/CBS/Sony Music decided to kill the LP you had no choice anyway for new music so you bit the bullet and dealt with the shit sandwich put on your plate.It sustained (it Was music right ?) but in the end still tasted like shit so when Meridian and AVA decided to make the machines BETTER then later PS Audio offered the (as far as I know anyway) FIRST external DAC we finally had a means to change our stars and maybe in the process get back what we had lost when they took our records away-THE MUSIC
OS vs. NOS DAC Stages
____________________________________________________
The claims by the NOS lovers is that the sonics are more "analog" sounding than a "normal" DAC with an oversampling digital filter while the "OS" crowd claims the NOS DACs lack detail and are thus not accurate so who is right ? Both ? Neither ?
Here is my take from personal experimentation in more than one system (my own various and the systems of others) and is an opinion based on personal taste and my close to forty years of having an interest in audio technology and music appreciation.
first and foremost let me get one thing out off my chest.I don't give a crap HOW something measures as long as it plays MUSIC and by that I mean the gear get the hell out of the way rather than try to be the "star" player.If during a listening session I find my attention is more diverted to the gear rack,the "visual" aspect rather than listening deeper into the music then that eval can only be considered a failure on the part of the equipment to get to the background allowing the music to be the focal point during the session.
for this reason i take damn near every "expert" opinion or company white paper or tech freaks recommendations for whatr they are-trying to choose system componants "Blindly" as in reading then purchasing instead of LISTENING then making a decision as it once was in the dark days of the local audio salon where the good ones would leave you alone with the gear playing YOUR music selections and not with cuts that portray the strengths oif the gear while staying away from those that do not OR using tech speak knowing you have no friggin' clue what they are saying but realizing the intimidation fasctor alone (no ne likes to look stupid) may seal the dale and thus earn the commision.
So with the above as the set-up here is my experience with both DAC topologies which for now will stay in the multibit DAC chip realm.
Typical NOS DAC digital:
At first blush yes,they do sound more analog than what you typically hear from a digital audio source;Harmonics sound natural,there is a "flow" to the performance that sounds like a complete piece rather than one disassembled then reassembled WRONG so that wile recognizable for what it is sounding so artificial you wonder just what the hell happened to the "soul",the human touch during reassembly.
Then you listen deeper and you hear "things" that you think at first is just you being a picky hard to please audiophile that is never happy so you self doubt in the knowing that hell.it IS better than what usually passes for good audio fare so it MUST be correct right ?
WRONG !
If you are like me and you have access to versions of the same exact performance but in other formats it becomes apparent there is something not quite right here.That even the lowly cassette version brings forth things tape hiss and all that are just NOT THERE in the NOS DAC digital version !
what things you ask ? How about a top end that even in my old age and with impaired hering (natural age attrityion,loud rock concerts in my youth,a damn lot or live ordinance going off all around me during my "war pig" years..).There is a sense that the music is quitting before my physical limitations hav a chance to kick in so while yes,th sound is pleasing it leaves one wanting,staining to hear things that will not come forth with those things being EXITEMENT !
Hell music is an emotional medium so when everything takes on a placid "everything is juuuuust fine here,no problems,just cruising along taking in the sights" quality then you may as well be in a freakin' elevator or at your worst nightmare wedding,you know,the ones where for fear of pissing off an segment of either side of the newly joined families you go for BLAND over "this is a new beginning so let us teat this joint up and let them KNOW we are HERE !"
It is soft,somewhat limp and lacks ultimate "life" and even though the music delineates very well it seems to be asleep on the uptake or put another way,the zero to MUZAK ramp up is agonizingly slow when compared to the pace portrayed by the identical LP version which sounds similiar but it is as if someone woke up the band and upon realizing they were just going through the paces decided to put on a SHOW that you won't forget any time soon !
Tonally nice,very easy to listen to (especially small scale music) but in the end a bit of a snore and for me that just won't do.
Typical OS DAC digial:
HOLY SHEEEIT ! THERE IS LIFE ON PLANET EARTH AFTERALL !
The life is back,there is pace,there is energy,hell it is DAMN EXCITING and life is again good !
But wait...........something....uh......er...something is......ah........hmmmmmm....nope.Don't like it.Sounding like a breath of fresh air after almost falling asleep but dammit,that is not right either but more "well,the band musta got that crank they were looking for 'cause MAN they are wired up tonight !Someone needs to toss a couple of 'ludes up there before someone has a damn heart attack !
what at first listen sound like the energy and life were put back,that the upper end extension has thankfully returned,that what youy wanted to hear is finally being played becomes a shortened listening sessions because for some unkown (at first) reason you find you are not relaxing but tensing up and that if someone were to look at your face unknown by you they would think you were pondering a weighty problem needing closure which in the end is kinda sorta true because while exciting it wears badly and you find yourself turning the music DOWN where you formerly in an attempt to gain same damn excitement in your life turned it UP !
WTF ?
Hard to please ?
Well yes.Listening to music is about as personal experience as it gets so if you are NOT building a system and selecting to please yourself but others than no amount of audio forum "the guru speaks" can help you and I feel for ya 'cause you are lost in the forest and have no idea which way is home and may not recognize it even if you see it your self confidence level so low.
For me personally what at first passes for detail and "life" transforms in a not too very long time to "artificial".Yes there is life but not REAL life,artificially "enhanced" larger than real added life (many call this detailed thus MUST be accurate because everything is so etched in space).Yes there is detail but it LEAPS OUT becoming a separate entity with a life of its own instead of a supporting player on team music.It is the electronics that want center stage and no matter who or what the performance they are not backing off without a fight and that "fight" usually on the wrong battlefield so rather than confront the problem head on,to yell "HEY ASSHOLE ! Down in front !" most instead try to listen "past" the spotlight hogging would be superstar to try and hear what the rest of the band is playing and that is where the "strain" comes in.Some call this "Digititus".I call it "Headache" because over time if I go above a certain volume point is EXACTLY what I get.
So what is the point ?
The point is most efforst at digital audio are imperfect at best and flat out suck at worst and you can choose to sit in either camp and say all day long your way is best and that would be no more than the town drunk boasting he can whip anyone's ass after he has had a few too many nips and before he falls down a flight of stairs and breaks his OWN neck saving others the task they starting to tire of his same old dog and pony show.
Truth is 95% of the NOS DAC stages roll off the highs and are oooooh soooo sloooow on the uptake (though they DO resolve on the downside,the decay portion well).They sound GREAT with the human voice,single or small group musical instruments or pretty much any musical event that would or could in a pinch fit in a good sized listening room,anything not too fast or powerful (read dynamic) but move to a larger venue ? High energy electrified instruments ?
Nope.Pleasant and you won't get a headache but you MAY fall asleep while listening instead of getting caught "air guitaring" or dancing around like an idiot thnking no one else is at home because you had the damn music so ,loud to compensate for the lack of dynamic life you never heard the door open and close ( I HATE that !)
With the OS DAC stages it is almost the exact opposite.You start out cranking the toons then find yourself backing down the level during certain passages when rather than jumping around like an idiot your attention SUDDENLY is focused on the equipment rack as if by giving a nasty look whatever just happened will NOT happen again because your gaze told it "look jerky,you do that again and it will go badly for YOO !"
...but it does and eventually you shut down and go do the "stuff" you should have been doing anyway but being "home alone" an unattended figured why not playb a bit og hookey and listen to some jams LOUD because for once no one else is at home yelling at you to "turn that sh*T down !"
It really sucks when you actualy have a free pass to be an idiot and you find the gear holds you back from realizing ultimate happy place and that for me is the majority of typical digital gear no matter what the source of.
So from the above bleak picture you would think I am "anti" digital,that I am one of the "analog or die" types but that isn't even close to true.I just want the same experience playing a Cd as I have and have pretty much always had during most of my adult life-music as escape mechanism,gear as the means to get there-and no more so I have for these many years twiddled and tweaked,cursed and cried trying get my CDs to sound like "clones" of my LPs.
Hell.If I had my way the turntable would be a frequently dusted decoration abd my Lp collection just that,a "collection" much like a coin or stamp collection:a point of pride but NO WAY would I spend the coins or post a letter wqith the stamps !
There is a naturalness,an emotional componant,hell MUSIC when I play an LP that I have rarely heard with any other medium not called "master tape" (if you thinks LPs are a pain in the ass to play.........) that I just don't get in the "perfect" digital realm which is either sanitized,cold and sterile "machine" music or lifeless baby cereal or like hospital food.Yes you will live but if this is as good as it gets would you WANT to ?
So my "fiddling" is always with my LP version as the control and my ongoing "project" as the ultimate goal and I have to say up front for me it begins and ends with an OS DAC then once I am confident I have done all I can do within my capabilities to at least have THAT part right consider everything from the DAC chip anlog outputs and beyond fair fair game and by fair game I mean if I get an idea or even a "twitch" I break contact and start the process all over again.
One thing I do NOT have is an analog filter anywhere in the signal path other than a "natural" rolloff,a system "bandwidth limiter" for lack of a better word dead smack in the middle of my passive line stage/line controller.Other than that is is WIDE OPEN BAYBEE even though the intended purpose of the digital filter from jump was so you could shift (not eliminate but move) the frequency of the anti-alising filter UP in direct relationship with the "X" of the digital filter so for instance if the digital filter is x4 then you can "shift" the f3 of the low pass filter UP by the same amount X4 the "normal" x1 which redbook CD being sampled at 44.1kHz means the best you can do is 22kHz and that must be gentle of it impacts the frequencies below 20kHz on too large a scale but being a gentle slope means you are also letting in digital artifacts,the source of the "digitalis" while too steep to avoid it means blowing the upper octave phasing all to hell and with it any shot at a good sound stage so while you may get the harmonics right you still will have a truncated stereo image,which you can mostly live with,or a "wandering" image,one that changes scale with volume level so the performance changes,something hard to live with and why most of the "technical" aspect of RBCD CD experimentation has been at both sides of the DAC chip itself and especially so the time/speed area where filters hold sway and why I try to keep my efforst also in a "narrow" corridor or you/I end up all over the map never knowing if you maybe mised something obvious but that was masked by other changes.
Having a known "control" is a must or you NEVER know where you stand and what may seem like forward progress may in fact be a step back (kind of like when someone does wholesale mods rather than incremental mods that are evaluated one at a time before proceeding with the next).A damn long journey that still has a fair piece to go but I AM gaining ground.
Remember,I listen and decide if I like a thing no matter who agrees with my choices or has issue with them because they can trot out reams of "white papers" or other technical writing to PROVE a thing sounds better even though they never even took the time to actually LISTEN to prove or disprove the theory.I rspect anyone who does not agree with my choices if they listened then decided between two or more options but for those who blindly buy into the "science",facts that tell your brain one thing while your ears say another ?
Not worth the time to argue with there being no possible outcome that is satisfying when you talk to a brick wall or a closed mind which is pretty much the same thing
On paper there is no contest in linearity,bass extension or dynamic range but in the time/phase realm ?
You woud be hard pressed to even find this spec mentioned other than in either a cryptic fashion or to tout some "new trick" circuitry used to separate one manufacturer's product from another's which you really need to take with a grain of salt mostly these fancily named circuits usually just a variation on what everyone else is offering- (no new "wheels" invented here mostly,just ad copy saying it was so
)Funny thing is,if you go ONLY by the raw data-the "spec" one would if they are to be beleived really start to question what they hear because there is a disconnect between the information and the reality of listening that mostly is so wide one would think either one side is delusional or the other flat out lying and the "WAR" is and has been raging for decades.So what is the truth of things ? What does the listening say that the data sheets do not ?
For one,that we can recover rapidly from small "warts" that occur over a very short time (pops/ticks) or that do not take away from the music even is ever present (low level hiss/noise) AS LONG AS the music draws you deeper into the actual performance because it is so emotionally "correct" that it grabs you-much like audience noise or the odd firecracker at a rock concert not taking away from a live musical event.
what we can NOT disregard is when the entire musical session is flawed or that no matter how hard you try you look to the person next to you and say "can't put my finger on it man but something is just not right here man.The drummer is out of sync or the guitars are a tad late or the singer is missing his marks but SOMETHING IS WRONG HERE.That or maybe like having a crap seat in a venue not known to have great acoustics or if it does,onely in a few slected sweet spots or maybe if an outdoor venue one where you find yourself in an "echo" chamber and you have to move around until you find the "null".These constants totally ruin what could have been a good experience but that in the end leave one wondering why the hell they bothered (been to some damn bad live events in my time and I have to say I usualy left pissed
) anyway.Here is how I translte the above into the domestic music playback experience with digital as the main topic and "sampling" as the sub topic.
Again,these are my findings based on many years of listening and remeber-when the CDP first came out:
1-ALL were 14 Bit NOS based because there were no digital filters yet
2-There WAS NO SPDIF stream other than for data testing because there were NO external DACs yet so jitter was not the problem it is now
3-ALL anti-aliasing filters SUCKED in the beginning being extremely steep brick wall filters in order to keep the aliasing out of the audible signal and why the oversampling digital filter was invented to begin with
4-Once designed then implemented It mostly didn't help the analog stages anyway the actual build sucking so bad
5-There was not a whole lot you cold do about it there being not many options to choose from (for example op-amps,quality passive parts,etc)
So you pretty much bought the machine and lived with pretty damn bad sound but that you could take to the car,play in a "walkman" or boom box and in the end get sound that was better than other alternatives plus once Columbia/CBS/Sony Music decided to kill the LP you had no choice anyway for new music so you bit the bullet and dealt with the shit sandwich put on your plate.It sustained (it Was music right ?) but in the end still tasted like shit so when Meridian and AVA decided to make the machines BETTER then later PS Audio offered the (as far as I know anyway) FIRST external DAC we finally had a means to change our stars and maybe in the process get back what we had lost when they took our records away-THE MUSIC
OS vs. NOS DAC Stages
____________________________________________________
The claims by the NOS lovers is that the sonics are more "analog" sounding than a "normal" DAC with an oversampling digital filter while the "OS" crowd claims the NOS DACs lack detail and are thus not accurate so who is right ? Both ? Neither ?
Here is my take from personal experimentation in more than one system (my own various and the systems of others) and is an opinion based on personal taste and my close to forty years of having an interest in audio technology and music appreciation.
first and foremost let me get one thing out off my chest.I don't give a crap HOW something measures as long as it plays MUSIC and by that I mean the gear get the hell out of the way rather than try to be the "star" player.If during a listening session I find my attention is more diverted to the gear rack,the "visual" aspect rather than listening deeper into the music then that eval can only be considered a failure on the part of the equipment to get to the background allowing the music to be the focal point during the session.
for this reason i take damn near every "expert" opinion or company white paper or tech freaks recommendations for whatr they are-trying to choose system componants "Blindly" as in reading then purchasing instead of LISTENING then making a decision as it once was in the dark days of the local audio salon where the good ones would leave you alone with the gear playing YOUR music selections and not with cuts that portray the strengths oif the gear while staying away from those that do not OR using tech speak knowing you have no friggin' clue what they are saying but realizing the intimidation fasctor alone (no ne likes to look stupid) may seal the dale and thus earn the commision.
So with the above as the set-up here is my experience with both DAC topologies which for now will stay in the multibit DAC chip realm.
Typical NOS DAC digital:
At first blush yes,they do sound more analog than what you typically hear from a digital audio source;Harmonics sound natural,there is a "flow" to the performance that sounds like a complete piece rather than one disassembled then reassembled WRONG so that wile recognizable for what it is sounding so artificial you wonder just what the hell happened to the "soul",the human touch during reassembly.
Then you listen deeper and you hear "things" that you think at first is just you being a picky hard to please audiophile that is never happy so you self doubt in the knowing that hell.it IS better than what usually passes for good audio fare so it MUST be correct right ?
WRONG !
If you are like me and you have access to versions of the same exact performance but in other formats it becomes apparent there is something not quite right here.That even the lowly cassette version brings forth things tape hiss and all that are just NOT THERE in the NOS DAC digital version !
what things you ask ? How about a top end that even in my old age and with impaired hering (natural age attrityion,loud rock concerts in my youth,a damn lot or live ordinance going off all around me during my "war pig" years..).There is a sense that the music is quitting before my physical limitations hav a chance to kick in so while yes,th sound is pleasing it leaves one wanting,staining to hear things that will not come forth with those things being EXITEMENT !
Hell music is an emotional medium so when everything takes on a placid "everything is juuuuust fine here,no problems,just cruising along taking in the sights" quality then you may as well be in a freakin' elevator or at your worst nightmare wedding,you know,the ones where for fear of pissing off an segment of either side of the newly joined families you go for BLAND over "this is a new beginning so let us teat this joint up and let them KNOW we are HERE !"
It is soft,somewhat limp and lacks ultimate "life" and even though the music delineates very well it seems to be asleep on the uptake or put another way,the zero to MUZAK ramp up is agonizingly slow when compared to the pace portrayed by the identical LP version which sounds similiar but it is as if someone woke up the band and upon realizing they were just going through the paces decided to put on a SHOW that you won't forget any time soon !
Tonally nice,very easy to listen to (especially small scale music) but in the end a bit of a snore and for me that just won't do.
Typical OS DAC digial:
HOLY SHEEEIT ! THERE IS LIFE ON PLANET EARTH AFTERALL !
The life is back,there is pace,there is energy,hell it is DAMN EXCITING and life is again good !
But wait...........something....uh......er...something is......ah........hmmmmmm....nope.Don't like it.Sounding like a breath of fresh air after almost falling asleep but dammit,that is not right either but more "well,the band musta got that crank they were looking for 'cause MAN they are wired up tonight !Someone needs to toss a couple of 'ludes up there before someone has a damn heart attack !
what at first listen sound like the energy and life were put back,that the upper end extension has thankfully returned,that what youy wanted to hear is finally being played becomes a shortened listening sessions because for some unkown (at first) reason you find you are not relaxing but tensing up and that if someone were to look at your face unknown by you they would think you were pondering a weighty problem needing closure which in the end is kinda sorta true because while exciting it wears badly and you find yourself turning the music DOWN where you formerly in an attempt to gain same damn excitement in your life turned it UP !
WTF ?
Hard to please ?
Well yes.Listening to music is about as personal experience as it gets so if you are NOT building a system and selecting to please yourself but others than no amount of audio forum "the guru speaks" can help you and I feel for ya 'cause you are lost in the forest and have no idea which way is home and may not recognize it even if you see it your self confidence level so low.
For me personally what at first passes for detail and "life" transforms in a not too very long time to "artificial".Yes there is life but not REAL life,artificially "enhanced" larger than real added life (many call this detailed thus MUST be accurate because everything is so etched in space).Yes there is detail but it LEAPS OUT becoming a separate entity with a life of its own instead of a supporting player on team music.It is the electronics that want center stage and no matter who or what the performance they are not backing off without a fight and that "fight" usually on the wrong battlefield so rather than confront the problem head on,to yell "HEY ASSHOLE ! Down in front !" most instead try to listen "past" the spotlight hogging would be superstar to try and hear what the rest of the band is playing and that is where the "strain" comes in.Some call this "Digititus".I call it "Headache" because over time if I go above a certain volume point is EXACTLY what I get.
So what is the point ?
The point is most efforst at digital audio are imperfect at best and flat out suck at worst and you can choose to sit in either camp and say all day long your way is best and that would be no more than the town drunk boasting he can whip anyone's ass after he has had a few too many nips and before he falls down a flight of stairs and breaks his OWN neck saving others the task they starting to tire of his same old dog and pony show.
Truth is 95% of the NOS DAC stages roll off the highs and are oooooh soooo sloooow on the uptake (though they DO resolve on the downside,the decay portion well).They sound GREAT with the human voice,single or small group musical instruments or pretty much any musical event that would or could in a pinch fit in a good sized listening room,anything not too fast or powerful (read dynamic) but move to a larger venue ? High energy electrified instruments ?
Nope.Pleasant and you won't get a headache but you MAY fall asleep while listening instead of getting caught "air guitaring" or dancing around like an idiot thnking no one else is at home because you had the damn music so ,loud to compensate for the lack of dynamic life you never heard the door open and close ( I HATE that !)
With the OS DAC stages it is almost the exact opposite.You start out cranking the toons then find yourself backing down the level during certain passages when rather than jumping around like an idiot your attention SUDDENLY is focused on the equipment rack as if by giving a nasty look whatever just happened will NOT happen again because your gaze told it "look jerky,you do that again and it will go badly for YOO !"
...but it does and eventually you shut down and go do the "stuff" you should have been doing anyway but being "home alone" an unattended figured why not playb a bit og hookey and listen to some jams LOUD because for once no one else is at home yelling at you to "turn that sh*T down !"
It really sucks when you actualy have a free pass to be an idiot and you find the gear holds you back from realizing ultimate happy place and that for me is the majority of typical digital gear no matter what the source of.
So from the above bleak picture you would think I am "anti" digital,that I am one of the "analog or die" types but that isn't even close to true.I just want the same experience playing a Cd as I have and have pretty much always had during most of my adult life-music as escape mechanism,gear as the means to get there-and no more so I have for these many years twiddled and tweaked,cursed and cried trying get my CDs to sound like "clones" of my LPs.
Hell.If I had my way the turntable would be a frequently dusted decoration abd my Lp collection just that,a "collection" much like a coin or stamp collection:a point of pride but NO WAY would I spend the coins or post a letter wqith the stamps !
There is a naturalness,an emotional componant,hell MUSIC when I play an LP that I have rarely heard with any other medium not called "master tape" (if you thinks LPs are a pain in the ass to play.........) that I just don't get in the "perfect" digital realm which is either sanitized,cold and sterile "machine" music or lifeless baby cereal or like hospital food.Yes you will live but if this is as good as it gets would you WANT to ?
So my "fiddling" is always with my LP version as the control and my ongoing "project" as the ultimate goal and I have to say up front for me it begins and ends with an OS DAC then once I am confident I have done all I can do within my capabilities to at least have THAT part right consider everything from the DAC chip anlog outputs and beyond fair fair game and by fair game I mean if I get an idea or even a "twitch" I break contact and start the process all over again.
One thing I do NOT have is an analog filter anywhere in the signal path other than a "natural" rolloff,a system "bandwidth limiter" for lack of a better word dead smack in the middle of my passive line stage/line controller.Other than that is is WIDE OPEN BAYBEE even though the intended purpose of the digital filter from jump was so you could shift (not eliminate but move) the frequency of the anti-alising filter UP in direct relationship with the "X" of the digital filter so for instance if the digital filter is x4 then you can "shift" the f3 of the low pass filter UP by the same amount X4 the "normal" x1 which redbook CD being sampled at 44.1kHz means the best you can do is 22kHz and that must be gentle of it impacts the frequencies below 20kHz on too large a scale but being a gentle slope means you are also letting in digital artifacts,the source of the "digitalis" while too steep to avoid it means blowing the upper octave phasing all to hell and with it any shot at a good sound stage so while you may get the harmonics right you still will have a truncated stereo image,which you can mostly live with,or a "wandering" image,one that changes scale with volume level so the performance changes,something hard to live with and why most of the "technical" aspect of RBCD CD experimentation has been at both sides of the DAC chip itself and especially so the time/speed area where filters hold sway and why I try to keep my efforst also in a "narrow" corridor or you/I end up all over the map never knowing if you maybe mised something obvious but that was masked by other changes.
Having a known "control" is a must or you NEVER know where you stand and what may seem like forward progress may in fact be a step back (kind of like when someone does wholesale mods rather than incremental mods that are evaluated one at a time before proceeding with the next).A damn long journey that still has a fair piece to go but I AM gaining ground.
Remember,I listen and decide if I like a thing no matter who agrees with my choices or has issue with them because they can trot out reams of "white papers" or other technical writing to PROVE a thing sounds better even though they never even took the time to actually LISTEN to prove or disprove the theory.I rspect anyone who does not agree with my choices if they listened then decided between two or more options but for those who blindly buy into the "science",facts that tell your brain one thing while your ears say another ?
Not worth the time to argue with there being no possible outcome that is satisfying when you talk to a brick wall or a closed mind which is pretty much the same thing
) that would use certain selected cuts to "help" you decide to buy what they are trying to push (and that got me when I was twenty something and paid out for a pair of crap speakers that were not cheap).
I have returned him a right hook as well ............. 
