There have been numerous forum conversations in the old BT thread, and some in the 'Why a new dac? thread (where soundbloke appeared and agreed with Jakob). Some of those conversations involved people like Scott Wurcer and other scientifically literate members. Having studied Cognitive Psychology myself, I know whether a lot of claims in that area are credible. I have observed Jakob's comments for a very long time. Jakob rarely ever said anything that was technically incorrect, although some of it was stuff people really didn't want to hear. In those few rare cases where Jakob misstated something, he corrected it as soon as the error came to his attention. He also has referred to the technical/professional sensory literature and academic textbooks, he has also described participating professionally in sensory testing, and casually performing blind sensory testing with audio preamps (casually, meaning not as part of his paid/professional sensory research).
I suspect you are one of those people that doesn't like what Jakob says, so you try to find justifications for rejecting it, whether or not it is actually scientifically correct or not. On the off chance Jakob got something wrong and didn't correct it, I will update my thinking accordingly, but doubtful it would have much overall effect on most of the other things he has said that are correct.
I suspect you are one of those people that doesn't like what Jakob says, so you try to find justifications for rejecting it, whether or not it is actually scientifically correct or not. On the off chance Jakob got something wrong and didn't correct it, I will update my thinking accordingly, but doubtful it would have much overall effect on most of the other things he has said that are correct.
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First of all, Jakob didn't say anything that was incorrect in the post you linked to. Your claim in that post was just another claim where you jumped to an unproven/unsupported conclusion about Jakob not bothering to converse with you. Did it ever occur to you that he might have considered talking to you a complete waste of time since you don't know anything about sensory testing and don't care to learn. You only want to win a debate as though science were decided like politics is.
Come on, find a post of Jakob's where he said something that is incorrect, link to that, and tell us why you think its incorrect.
Did you read my comments? Did you understand them? Did you want to understand them?
If we are talking about qualifications, then I have a Science Degree, and understand scientific methodology, so please show me the courtesy of pointing out specific errors, you believe I have made, when assessing Jakob"s arguement?
A degree in science does not assure competency in an advanced specialty area. Jakob has expertise in sensory testing, you don't.
Again, please show us the exact context where you think Jakob incorrectly referred to "errors in methodology" in the way you claim. Lets have a link to Jakob's exact words, not your interpretation or mis-interpretation of what you think he was saying.
EDIT: I'm beginning to see why Jakob would refuse to talk to you. Getting closer to that point myself. All we know is you think Jakob said something that was incorrect according to your reading of it. You are trying to support your claim here by pointing to another claim by you. That is not what I need to see if I am to consider revising my opinion of your claim here. I need to see Jakob's own words to see if they are correct or not.
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havent been here for a while it seems the project has developed alot.
i have almost finished mine a year or two ago in a hurry, and it sounds much better then my commercial dac (teac501). here are some pictures sorry for all the messy cables
Im finishing my pro and power amps now, and maybe return to the dac afterwards
i have almost finished mine a year or two ago in a hurry, and it sounds much better then my commercial dac (teac501). here are some pictures sorry for all the messy cables
Im finishing my pro and power amps now, and maybe return to the dac afterwards
Since you are so supportive of Jakob's position, I assumed you were already very familiar with what he has written, and would have no problem pointing out the specific problems you see in my arguement.
I pointed out to Jacob that the correct use of DBT is to "prove" a difference (ie reject the null hypothesis), and therefore should be used by people who rely on sensory perception to validate their observations. This is when he fell silent!
As for you refusing to talk to me, It doesn't really matter to me. There really isn't any point when you respond to specific questions, you don't like, with unsubstantiated waffle.
I gave up listening to you when you claimed you could hear distortions below -120dB
This thread is now getting burdened by an unwanted, unappropriate discussion on methodology. As a long time member at diyaudio.com the following suggestion may be offered to a moderator of this thread; please consider to split the post 5566 into a new thread. Holding a PhD myself I even might consider to contribute there, although a methodological issue is usually explored at more moderate mind temperature.
And now, in order to head on topic of this thread; Mark, I am preparing the AVCC power supply with some unused AD797 from the drawer.
And now, in order to head on topic of this thread; Mark, I am preparing the AVCC power supply with some unused AD797 from the drawer.
I'm all for DIY-ing if that's what one enjoys. Do you notice that I responded to Mark's posting of sound quality claim with no supporting evidence? That's not DIY-ing DACs.
You didn't understand what that meant either. Typical of you, apparently.
Look, you adjust something that changes HD down around -120dB measured. Then play some music and hear some audible change in distortion. Is it HD you are hearing, or IMD produced by the exact nonlinearity that was measured according to its HD? I can tell you the answer, what is audible is the IMD, which is at a much higher level than the corresponding HD. Its just easier to measure and refer to a nonlinearity according to the HD it produces.
Also, I heartily agree with Bruno Putzeys and Lars Risbo that lower distortion speakers (and other low distortion equipment) in a reproduction chain make small distortions more clearly audible that they would otherwise be. I use ultra low distortion audio equipment in my reproduction chain for that reason. What do you use? Want to compare reproduction systems?
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The following is what fellow forum member Jakob2 said about himself.
"As scottjoplin already pointed out, there are ties, as audio development was and is part of my work."
Very doubtful, although you might think he is.
You nailed it!
Sorry to let this thing get off the rails. Shouldn't reply to some people in the first place.
Happy to get back to thread topic.
.
i have almost finished mine a year or two ago in a hurry, and it sounds much better then my commercial dac (teac501). here are some pictures sorry for all the messy cables
Hi Paul,
Nice to hear from you and good to know you are happy with the modded dac so far. Also, thanks for the pics, we always like to look at pics of dac projects!
You could have just posted DIY-ing without bogus sound quality claim prior to some people responding.
In case anyone missed it, basic information about the ESS recommeded opamp AVCC supply is in the document on their downloads page: http://www.esstech.com/files/4514/4095/4306/Application_Note_Component_Selection_and_PCB_Layout.pdf
It shows one AVCC opamp, but two such circuits are needed, one for AVCC_L and one for AVCC_R. Also, the reference voltage for the AVCC opamps to follow should ideally come from a low noise voltage reference. LTC6655 has been used, and I have also suggested that LT3042 could probably serve well if dedicated to AVCC voltage reference use only.
There is a schematic for a proposed opamp AVCC supply attached to post #3003 in this thread. The changes I would make to it at this point are as described in post #5554.
If any dac modding questions come to mind, please ask and we will try to respond/answer, hopefully, in a helpful way.
It shows one AVCC opamp, but two such circuits are needed, one for AVCC_L and one for AVCC_R. Also, the reference voltage for the AVCC opamps to follow should ideally come from a low noise voltage reference. LTC6655 has been used, and I have also suggested that LT3042 could probably serve well if dedicated to AVCC voltage reference use only.
There is a schematic for a proposed opamp AVCC supply attached to post #3003 in this thread. The changes I would make to it at this point are as described in post #5554.
If any dac modding questions come to mind, please ask and we will try to respond/answer, hopefully, in a helpful way.
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Agreed, lots of unwanted posts from many just wanting to hurl abuse at Mark. He has provided lots of advice to many on this thread, often his own views but more often than not supported by many. What I like to think is that he's provided a sounding board, never critical, just sharing his opinion, giving us all a 'menu' of modifications to choose from.
Oh boy, this thread and some other in this section used to be enjoyable read. But recently they are under troll attack. There are some evil harmonics bringing nothing useful but harsh noise. And there is some guy attempting at na(i)ling it down but always missing the point. List goes on.
I must express my disapproval of them and their behavior and my support for the very valuable contributors. Former are useless and in abundance while latter are scarce.
Bless the ignore list and All hail the Moderators.
I must express my disapproval of them and their behavior and my support for the very valuable contributors. Former are useless and in abundance while latter are scarce.
Bless the ignore list and All hail the Moderators.
Guys, thank you for the support. Helps make participation seem worthwhile to know that efforts are found to be helpful.
Just remembered something else on topic which is that AD797 datasheet has some advice about using large bypass caps for heavier current loads, something possibly applicable to good bass response in AVCC applications.
Please see top of page 13 in the document at: https://www.analog.com/media/en/technical-documentation/data-sheets/AD797.pdf
Symptoms of a problem might include ringing on power pins as observed with a scope. Could have an adverse effect on dac sound quality, so perhaps something to take a look at or experiment with to see if any difference in 'sound quality' depending on series resistor values.
Please let us know if you find anything interesting. The group would certainly appreciate any new information.
Just remembered something else on topic
which is that AD797 datasheet has some advice about using large bypass caps for heavier current loads, something possibly applicable to good bass response in AVCC applications.Please see top of page 13 in the document at: https://www.analog.com/media/en/technical-documentation/data-sheets/AD797.pdf
Symptoms of a problem might include ringing on power pins as observed with a scope. Could have an adverse effect on dac sound quality, so perhaps something to take a look at or experiment with to see if any difference in 'sound quality' depending on series resistor values.
Please let us know if you find anything interesting. The group would certainly appreciate any new information.
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Its a function of "freedom of speech" that you are as free to express your opinions, as I am to ignore them.
By the way, do you own this DAC? Have you even heard it?
I do and I listen to it every day.