Hi,
I'd try it, but as we decided against adopting the ESS DAC's in products (part of it was their way of doing business and supporting their products - which makes Cirrus look good - in sharp contrast to WM or AKM) and only had the 9008, so it will be hard to get the necessary support from ESS for that. Maybe Kurt & Hurtig could try it while they evaluate the ESS Chip?
Ciao T
I'd try it, but as we decided against adopting the ESS DAC's in products (part of it was their way of doing business and supporting their products - which makes Cirrus look good - in sharp contrast to WM or AKM) and only had the 9008, so it will be hard to get the necessary support from ESS for that. Maybe Kurt & Hurtig could try it while they evaluate the ESS Chip?
Ciao T
"Black background" is not a result of low noise, but a result of lack of insensitivity to low level signals, due to exessive capacity.
FET´s always produce this.
In the real world, there is no such thing as black background, and it should not be present in reproduced music either.
The shunts do have no audible noise, and audibly less noise than the former used discrete series regulator.
Regarding the guys discribing the earlier DACs sound in the other thread, I would not pay to much attention to that, they are mostly emotional guys, with their own modified Audio Note NOS tube DAC at steak, which they obviously seem to like better. I heard it, but I won´t comment on that.
Just look at their designs and modifications, and get the idea yourself.
I think we ought to just summarize the design goals for this project.
I think this is about it.
- Everything is to be on one single board incl. PSU
- No NOS DAC is suitable for this project
- No tubes will be included
- Discrete analog design is crusial
- No FET´s will be designed into this project
- As many parts as possible from one single vendor
I think this is about it.
Another "We are the champions and the others do everything wrong" - thread.
That posted schematic looks like any manufacturer's application notes puzzled together.
Hi Kurt,
Hmmm. This is not my experience at all.. ;-)
Also, I think the jump from "black background" to "excessesive capacitance" is unsubstantiatable. More so as correct design (as I suggested for the FET's BTW) will dramatically reduce the issues from the capacitance.
In the end it is a question to choose ones poison.
Both Fets and Bipolar transistors have problems with parasitics, just different ones and one needs to address them on a design level to get good results.
Hmm, that depends. If you feel the need to add some low level noise to deal with the fact that music is recorded with sections of what amounts to digital silence and you find that to be unnatural, maybe you would be better off adding more dither to the digital signal.
Which is good. But with the kind of zero feedback circuits you use any noise will make it back into the signal. And noise that is directly audible as hiss or hum still has subtle effects on the sound quality. I find that I prefer less noise form the supplies each and every time, even if the noise is already quite low.
I generally prefer not be dismissive if people are critical of my product(s), no matter how much I feel I have made my product to be "right". I may still not choose to act on such criticism, but I will always give it a good hearing and consider it, before doing so.
But of course you have the privilege to ignore criticism thoroughly, but then there is little point inviting it in the first place.
Ciao T
Hmmm. This is not my experience at all.. ;-)
Also, I think the jump from "black background" to "excessesive capacitance" is unsubstantiatable. More so as correct design (as I suggested for the FET's BTW) will dramatically reduce the issues from the capacitance.
In the end it is a question to choose ones poison.
Both Fets and Bipolar transistors have problems with parasitics, just different ones and one needs to address them on a design level to get good results.
Hmm, that depends. If you feel the need to add some low level noise to deal with the fact that music is recorded with sections of what amounts to digital silence and you find that to be unnatural, maybe you would be better off adding more dither to the digital signal.
Which is good. But with the kind of zero feedback circuits you use any noise will make it back into the signal. And noise that is directly audible as hiss or hum still has subtle effects on the sound quality. I find that I prefer less noise form the supplies each and every time, even if the noise is already quite low.
I generally prefer not be dismissive if people are critical of my product(s), no matter how much I feel I have made my product to be "right". I may still not choose to act on such criticism, but I will always give it a good hearing and consider it, before doing so.
But of course you have the privilege to ignore criticism thoroughly, but then there is little point inviting it in the first place.
Ciao T
@ ThorstenL:
I think you misunderstand. We do not want to add any background noise, to get rid of the black background. Case is, the almost no music is recorded on such a black background. That simply isn't the nayure of music.
Typically FET based gear, tend to en up with this black background anyway, which can only be the result of low level (and higher frequency withing the audio range) signals beeing somehow cut away. The fact that the gate is quite capacitive, really do back up this fact.
We still would like you to pay us a visit, and bring one of your own references, to cmpare with our CS4398 based DAC.
BTW: You mention that you have a great influence on what chips end up in high end audio gear. Could you tell us which products you have been involved in?? Maybe that could explain our different opinions....
I think you misunderstand. We do not want to add any background noise, to get rid of the black background. Case is, the almost no music is recorded on such a black background. That simply isn't the nayure of music.
Typically FET based gear, tend to en up with this black background anyway, which can only be the result of low level (and higher frequency withing the audio range) signals beeing somehow cut away. The fact that the gate is quite capacitive, really do back up this fact.
We still would like you to pay us a visit, and bring one of your own references, to cmpare with our CS4398 based DAC.
BTW: You mention that you have a great influence on what chips end up in high end audio gear. Could you tell us which products you have been involved in?? Maybe that could explain our different opinions....
Hi,
Well, I am not sure what you are trying to get at. Yes, most well recorded music that uses mainly analogue methods will have some sound between notes. In some cases it will be just microphone (and electronic noise), in others it will be the reverb of the acoustic recording space (this is rare nowadays though).
A lot of modern recordings are heavily multitracked and often record at extreme 'closeup" microphone positions (which reduce microphone noise but give a wrong tonal picture) and with semi-anechoic booth per instrument. Such recordings can have "digital zero" sections on CD and are often devoid of real natural room sound.
Okay, let's take this and deconvolute it.
You note 1: "Typically FET based gear, tend to en up with this black background anyway"
What I was proposing is NOT Typhical Fet Gear. Nor does it sound like you describe BTW.
You assert 2: "(this) can only be the result of low level (and higher frequency withing the audio range) signals beeing somehow cut away."
That is an assumption and one that is neccesarily true. Much as said will depend on the exact design. It is not my experience that well designed equipment incorporating Fets sounds like you describe, nor do any of the measurements we can take substantiate such behaviour.
Of course, some early Fet based designs had severe problems and I remember myself refusing to use FET based Pro-Audio Amp's due to the "Fet Mist" sound they produced. This sound however was not the result of the Fet as such, but of using Fet much like a BJT without actually accounting for it's unique and different parasitics.
You mention 3: "The fact that the gate is quite capacitive, really do back up this fact."
Well, if you employ a cascode (or even better, folded cascode - which allows the signal to be referenced to the imaginary ground, rather than to the supply line) this capacitance is essentially neutralised and very little remains active.
On the positive side - J-Fets (and Mosfets - but mosfets do not lend themselves well for low poer applications) do not have the constant and signal modulated base current nor the (often significant) base noise current, which make using BJT's a bit of a challenge.
As said, I feel it is less an issue of the precise device, but of how you use it that matters (also goes for tubes and even op-amp's of course).
Hmmm, my reference CD-Player weighs nearly 50Kg in it's packaging (and 28Kg without packaging). I don't fancy carrying that. But I am sure you can find a fairly nearby dealer to drop over and have a listen.
Not generally as in "what goes into all high end gear" but as in "what goes into products for which I am the lead designer"...
I tend not throw my achievements into everyones face the way some people do. If you really need to know you could always google me or look at my profile... ;-)
Ciao T
PS, I used to post on various boards under the Nom Du Guerre "Kuei Yang Wang"...
Well, I am not sure what you are trying to get at. Yes, most well recorded music that uses mainly analogue methods will have some sound between notes. In some cases it will be just microphone (and electronic noise), in others it will be the reverb of the acoustic recording space (this is rare nowadays though).
A lot of modern recordings are heavily multitracked and often record at extreme 'closeup" microphone positions (which reduce microphone noise but give a wrong tonal picture) and with semi-anechoic booth per instrument. Such recordings can have "digital zero" sections on CD and are often devoid of real natural room sound.
Okay, let's take this and deconvolute it.
You note 1: "Typically FET based gear, tend to en up with this black background anyway"
What I was proposing is NOT Typhical Fet Gear. Nor does it sound like you describe BTW.
You assert 2: "(this) can only be the result of low level (and higher frequency withing the audio range) signals beeing somehow cut away."
That is an assumption and one that is neccesarily true. Much as said will depend on the exact design. It is not my experience that well designed equipment incorporating Fets sounds like you describe, nor do any of the measurements we can take substantiate such behaviour.
Of course, some early Fet based designs had severe problems and I remember myself refusing to use FET based Pro-Audio Amp's due to the "Fet Mist" sound they produced. This sound however was not the result of the Fet as such, but of using Fet much like a BJT without actually accounting for it's unique and different parasitics.
You mention 3: "The fact that the gate is quite capacitive, really do back up this fact."
Well, if you employ a cascode (or even better, folded cascode - which allows the signal to be referenced to the imaginary ground, rather than to the supply line) this capacitance is essentially neutralised and very little remains active.
On the positive side - J-Fets (and Mosfets - but mosfets do not lend themselves well for low poer applications) do not have the constant and signal modulated base current nor the (often significant) base noise current, which make using BJT's a bit of a challenge.
As said, I feel it is less an issue of the precise device, but of how you use it that matters (also goes for tubes and even op-amp's of course).
Hmmm, my reference CD-Player weighs nearly 50Kg in it's packaging (and 28Kg without packaging). I don't fancy carrying that. But I am sure you can find a fairly nearby dealer to drop over and have a listen.
Not generally as in "what goes into all high end gear" but as in "what goes into products for which I am the lead designer"...
I tend not throw my achievements into everyones face the way some people do. If you really need to know you could always google me or look at my profile... ;-)
Ciao T
PS, I used to post on various boards under the Nom Du Guerre "Kuei Yang Wang"...
I did. And your stuff is a little on the extreme side, so I am just curious as to why you feel you have anything to offer in a $199 ss dac diy thread? I ask because you seem to inject a lot of OT negativity into something that should be fun and stimulating. Your tone is kinda...I don't know...umm...Asperger-like.
Not at all!
But if These two guys (who are actually only speaking for themselves) really would like it, I´d be worried, since we´ve tried very hard to move as far away from "tubelike" sound as possible.
There is no champs and no wrongs, everyone is obliged to like whatever sound he/she favours.
This project though will not be designed with any sonic preference at all.
It will be designes at pretty much everything else is designed, which in general is to decide which components to use, based on good and sound technical facts, then build, test and finish.
@Thorsten
I´ve auditioned a pretty large number of amplifiers, both integrated and separated ones.
The ones with FET´s has always been easy recognizeable in their sonic performance. They simply miss low level information which BJT´s don´t.
It has nothing to do with noise really, but sensitivity to low level signals.
I.e. as you mention acoustic AB recordings of i.e a symphonic orchestra, no silence exists, there is always some sort of sound, may it be breathing, fumbeling around, movements of people or papers and so on, which is clearly audible if the performance is experienced live. This kind of stuff simply disappears and turns into blackness in all the FET amps I´ve heard, btw. the same thing goes for transformercoupled tube amps.
This lack of low level performance also leads to corruption of the subtle sonic fingerprint of the acoustical surroundings.
I hifi gear for generalpurpose, this is of no concern, but if you want high fidelity sound reproduction, this is crusial.
I do know tweaks that provides, amongst other things, this black background i.e. most MIT cables do.
And I can assure you that neither do I like it, nor is it natural.
I´ve auditioned a pretty large number of amplifiers, both integrated and separated ones.
The ones with FET´s has always been easy recognizeable in their sonic performance. They simply miss low level information which BJT´s don´t.
It has nothing to do with noise really, but sensitivity to low level signals.
I.e. as you mention acoustic AB recordings of i.e a symphonic orchestra, no silence exists, there is always some sort of sound, may it be breathing, fumbeling around, movements of people or papers and so on, which is clearly audible if the performance is experienced live. This kind of stuff simply disappears and turns into blackness in all the FET amps I´ve heard, btw. the same thing goes for transformercoupled tube amps.
This lack of low level performance also leads to corruption of the subtle sonic fingerprint of the acoustical surroundings.
I hifi gear for generalpurpose, this is of no concern, but if you want high fidelity sound reproduction, this is crusial.
I do know tweaks that provides, amongst other things, this black background i.e. most MIT cables do.
And I can assure you that neither do I like it, nor is it natural.
Hi,
Okay, first, I do not know exactly what you have been listening to, however note that "Mosfet's in the output stage of a high NFB Amplifier" does not happen to say anything about "J-Fet in low level stages of zero NFB Amplifier".
I have done something different to you. Instead of listening to what other do and derive a theory from that, I actually build literally the same circuits with BJT's and J-Fets (and Mosfets and Tubes to be precise) trying to observe "all else being equal" as much as feasible.
Then I measured them and listened to them (listening single blind). I then noted my empirical results and use them. I never bothered with any theories much. Because in theory there is no difference between theory and practice, but in practice there always is a lot of difference to any theory.
Yet VERY few recordings are done this "live", usually there is no audience and many other things differ as well. And even then, much of this will drown in microphone noise.
Well, forgive me for saying so, but my experience and listening does not agree. I find this "fade to black" by far more common in bipolar circuits with Class AB output stages.
As for "transformer coupled", I hope you are aware that many of the recordings where you may actually hear anything like what you describe where made using recording equipement that was not only transformer coupled (real recroding/radio/TV grade pro audio stuff still tends use real transformers, all that "electronic transfomer" stuff is firmly in the pro-sumer and semi-pro market but rare in true high end recording gear) but often even tubed for older recordings.
Of course, tubes and transformers only steal low level information during playback, but of course preserve it extra well (which is in fact what they really do) during recording.
Yeah, right.
Kurt, I do not dispute your experiences, but I dispute the generalisations derived therefrom.
I think you will find if you sufficiently widen the field that much high end gear is not producing sound in a natural and realistic way. And if you keep an open mind you will find that this has less to do with the specific device or basic principle used and much, much more with the execution.
However, far be it from me to try to cure you from your prejudices (I am sure you worked hard to acquire them), so by all means used discrete BJT's if that floats your boat. Just make sure you correctly address their parasitics and problems correctly.
Hint, the lookback impedance from the base is where it's at and while balancing things in differential stages helps to reduce the even order elements of the distortion added by non-zero lookback impedance, it does nothing about the odd order stuff.
Ciao T
Okay, first, I do not know exactly what you have been listening to, however note that "Mosfet's in the output stage of a high NFB Amplifier" does not happen to say anything about "J-Fet in low level stages of zero NFB Amplifier".
I have done something different to you. Instead of listening to what other do and derive a theory from that, I actually build literally the same circuits with BJT's and J-Fets (and Mosfets and Tubes to be precise) trying to observe "all else being equal" as much as feasible.
Then I measured them and listened to them (listening single blind). I then noted my empirical results and use them. I never bothered with any theories much. Because in theory there is no difference between theory and practice, but in practice there always is a lot of difference to any theory.
Yet VERY few recordings are done this "live", usually there is no audience and many other things differ as well. And even then, much of this will drown in microphone noise.
Well, forgive me for saying so, but my experience and listening does not agree. I find this "fade to black" by far more common in bipolar circuits with Class AB output stages.
As for "transformer coupled", I hope you are aware that many of the recordings where you may actually hear anything like what you describe where made using recording equipement that was not only transformer coupled (real recroding/radio/TV grade pro audio stuff still tends use real transformers, all that "electronic transfomer" stuff is firmly in the pro-sumer and semi-pro market but rare in true high end recording gear) but often even tubed for older recordings.
Of course, tubes and transformers only steal low level information during playback, but of course preserve it extra well (which is in fact what they really do) during recording.
Yeah, right.
Kurt, I do not dispute your experiences, but I dispute the generalisations derived therefrom.
I think you will find if you sufficiently widen the field that much high end gear is not producing sound in a natural and realistic way. And if you keep an open mind you will find that this has less to do with the specific device or basic principle used and much, much more with the execution.
However, far be it from me to try to cure you from your prejudices (I am sure you worked hard to acquire them), so by all means used discrete BJT's if that floats your boat. Just make sure you correctly address their parasitics and problems correctly.
Hint, the lookback impedance from the base is where it's at and while balancing things in differential stages helps to reduce the even order elements of the distortion added by non-zero lookback impedance, it does nothing about the odd order stuff.
Ciao T
Hi,
The latest completely clean MOSFET amp I listened to was Belles pre and power. But there has been several others and countless op-amps with FETs.
Seems cool
Yeah right - theory and practice often differs more than one like.
I think I can count hundreds in my collection, but I might be an AB nerd.
Well I do not own an AB output stage.
I have recordings made with both TL´s and normal mics done at the same venue and at the same time and placement, so I do know ecxactly what transformers in that stage does to sound.
Transformers are IMHO the worst component to find in audio gear what so ever, closely followed by caps.
Which excactly goes for the 8416 and the 4398 as well.
The implementation is the final component, which easily can turn things upside down.
The latest completely clean MOSFET amp I listened to was Belles pre and power. But there has been several others and countless op-amps with FETs.
Seems cool
Yeah right - theory and practice often differs more than one like.
I think I can count hundreds in my collection, but I might be an AB nerd.
Well I do not own an AB output stage.
I have recordings made with both TL´s and normal mics done at the same venue and at the same time and placement, so I do know ecxactly what transformers in that stage does to sound.
Transformers are IMHO the worst component to find in audio gear what so ever, closely followed by caps.
Which excactly goes for the 8416 and the 4398 as well.
The implementation is the final component, which easily can turn things upside down.
Did you try the Squeezebox Duet/Controller? It has a great interface. I was actually a beta tester of that device a few years ago. It's easily the best audio device I've ever had, in terms of convenience.
This thread really is not about Squeezeboxes.... But... Talking about nice interfaces, take a look at Apple Airport Express + Itunes + IPOD Touch/IPHONE as remote. This is a great solutions, talking about interfaces. Later we will take a look at the Airport Express, in order to make a better SPDIF output on it. Then I believe we have a "SB-killer"....
The DAC project is still moving forward. I am in the middle of integrating a discrete NFB analog stage on the ESS 9018 board. Guess this could be a great DAC!
The DAC project is still moving forward. I am in the middle of integrating a discrete NFB analog stage on the ESS 9018 board. Guess this could be a great DAC!
Aahhh.... This could actually be a transformer coupled SPDIF. The Airport Express has an optical output, which is great in terms of electrical isolation. In all these "Embedded computer" streamers which also goes for the SB's, I can see a resaon to use a transformer, in order to have som isolation.
We also discussed another solution, that will NOT include having to open the AE. Simply by using the optical output, convert it to electrical and then add some serious jitter reduction. This is a more DIY friendly version. However... We still need to test both solutions, and let the ear decide.
We also discussed another solution, that will NOT include having to open the AE. Simply by using the optical output, convert it to electrical and then add some serious jitter reduction. This is a more DIY friendly version. However... We still need to test both solutions, and let the ear decide.
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