Lundahl could fit. Any other recommendation? What does the experience say, is the blocking cap needed or not?jean-paul said:
If someone has surplus samples, since I can not source it easily, I would gladly accept one (or a few) for the board (s).
I did tried for a short more radical than usual low passing of the I2S line and I was not satisfied neither with what I have heard nor with the waveform I have seen. But I might be wrong. Anyway, existing I2S line can accept low passing resistors, one could try to mount shunt cap at their output side to accomplish Henk’s idea.
As about the signal level conditioning, it is no option to implement it in the board before I try it.
I have my 😡 discrete I/V stage.
😉
I will add the pads for shorter caps, that is all. Only the ground plane will be a bit violated with this which won’t be that important. I am definitely not in the position or in will to sell neither kits nor any part for this project. I will work for now to finish the version I have started and I have the other projects that already late because of this. One day it might be offered some another DAC board version, but that is the future.
Pedja
For a transformer suggestion.. have you considered the ones by these guys? http://www.scientificonversion.com/
They quote very low noise and jitter specs.. have no direct idea how good they are, but they make a good case for themselves with interesting test papers and industry white papers.
Those are good reading anyway from an understanding and designer point of view.
I happen to live very close to them, as it turns out.. maybe I could get a few samples shipped off to you?
Jon
They quote very low noise and jitter specs.. have no direct idea how good they are, but they make a good case for themselves with interesting test papers and industry white papers.
Those are good reading anyway from an understanding and designer point of view.
I happen to live very close to them, as it turns out.. maybe I could get a few samples shipped off to you?
Jon
Thanks for the offer Jon, I certainly am interested.
It is not quite clear from their site, do they normally sell transformers in small quantities? Also, I can not find the prices and info like exact measures and pinout. Do they have this info published?
Pedja
It is not quite clear from their site, do they normally sell transformers in small quantities? Also, I can not find the prices and info like exact measures and pinout. Do they have this info published?
Pedja
Hi Anthony,
It is not that nice feeling when you do the same thing twice in two months… and what if again (you never know)… I’ve sent the file this morning finally, prototype board will be finished till Friday, eventually next Monday. Results in about 10 days after that.
The changes done:
The AD844s are moved a few cm back and the ground plane opened around them.
Simple current sourced single end JFET output buffer added to the board.
There is a provision for Scientific Conversion (SC944-05) S/PDIF transformer.
Added pads to enable usage of 10mm lead spacing TDA decoupling caps.
A few smaller changes that would take me a bit longer to list. Anyway, I’ll post new documents to my site in a few days.
Pedja
It is not that nice feeling when you do the same thing twice in two months… and what if again (you never know)… I’ve sent the file this morning finally, prototype board will be finished till Friday, eventually next Monday. Results in about 10 days after that.
The changes done:
The AD844s are moved a few cm back and the ground plane opened around them.
Simple current sourced single end JFET output buffer added to the board.
There is a provision for Scientific Conversion (SC944-05) S/PDIF transformer.
Added pads to enable usage of 10mm lead spacing TDA decoupling caps.
A few smaller changes that would take me a bit longer to list. Anyway, I’ll post new documents to my site in a few days.
Pedja
Tda1541a non-o/s DAC PCB
dear Pedja,
last week my friend go to taiwan computor EXPO.
My friend was a computor monther board producer & display card dealer in hong kong.
He visit several display card factory for the new products as
http://www.ati.com
They tell my friend some information about the PCB coated material.
They said one new material which was black in colour, will not carry any stastic which can prevent the digital error message during high speed transmitting the data.
So U can see that the new high speed display all use this black colour to coat the PCB.
This information only for U to reference only.
hope this can help.
thnaks
thomas
dear Pedja,
last week my friend go to taiwan computor EXPO.
My friend was a computor monther board producer & display card dealer in hong kong.
He visit several display card factory for the new products as
http://www.ati.com
They tell my friend some information about the PCB coated material.
They said one new material which was black in colour, will not carry any stastic which can prevent the digital error message during high speed transmitting the data.
So U can see that the new high speed display all use this black colour to coat the PCB.
This information only for U to reference only.
hope this can help.
thnaks
thomas
Hi all,
Considering repeated objections about involvement of the commercial interest in (abuse of) this Forum, and despite of the fact I am not named in any of them (at least I have not noticed that), I found myself called to respond.
Because:
1. I went into this after I have found certain interest for the board for such project. I found previously a few efforts/intentions of the others to start something like this without results.
2. I would not have any problem to run such offer exclusively from my own site with unchanged success.
3. Other than link I have in the profile, I am linking my site very rarely.
4. I would not have any problem to make this thread started by someone else.
5. I was trying not to bump this thread without important reason.
6. Considering involved effort, time and the costs I have at one side and offered price at the other, I am not able to hear even once that I am exploiting something.
7. It is not bad to know that I have not planned to deal with this (this revision) 3 months and taken responsibility for this project keeps me from some things which would be normally more important now to me.
I have decided:
1. To ask moderators to close this thread and possibly to move it to the Trading Posts Forum. If more than 2-3 members with known real name want that, I am agreed with deleting this thread as an obscene.
2. To ask moderators to close the referenced Wiki page.
The project itself will continue its way. All the information will be in my site.
I have the thread and Wiki page saved locally and all interested will get his/her own board(s) when it comes the time.
I will normally continue to be the member of this forum.
Pedja
PS: To prevent any further misunderstanding: this project is my own project, intended to be shared with those interested. It is not offered as best_ever, best_buy, success_guaranteed, you_need_it, must_have or anything – it is just offered to those intended to build TDA1541A non-oversampling DAC. Once more, I will not sell the kits or any part for the project, just the board. And I will not sell it before I personally am satisfied.
Considering repeated objections about involvement of the commercial interest in (abuse of) this Forum, and despite of the fact I am not named in any of them (at least I have not noticed that), I found myself called to respond.
Because:
1. I went into this after I have found certain interest for the board for such project. I found previously a few efforts/intentions of the others to start something like this without results.
2. I would not have any problem to run such offer exclusively from my own site with unchanged success.
3. Other than link I have in the profile, I am linking my site very rarely.
4. I would not have any problem to make this thread started by someone else.
5. I was trying not to bump this thread without important reason.
6. Considering involved effort, time and the costs I have at one side and offered price at the other, I am not able to hear even once that I am exploiting something.
7. It is not bad to know that I have not planned to deal with this (this revision) 3 months and taken responsibility for this project keeps me from some things which would be normally more important now to me.
I have decided:
1. To ask moderators to close this thread and possibly to move it to the Trading Posts Forum. If more than 2-3 members with known real name want that, I am agreed with deleting this thread as an obscene.
2. To ask moderators to close the referenced Wiki page.
The project itself will continue its way. All the information will be in my site.
I have the thread and Wiki page saved locally and all interested will get his/her own board(s) when it comes the time.
I will normally continue to be the member of this forum.
Pedja
PS: To prevent any further misunderstanding: this project is my own project, intended to be shared with those interested. It is not offered as best_ever, best_buy, success_guaranteed, you_need_it, must_have or anything – it is just offered to those intended to build TDA1541A non-oversampling DAC. Once more, I will not sell the kits or any part for the project, just the board. And I will not sell it before I personally am satisfied.
Pedja, as a mod I think it is not necessary to close the thread nor to move it to the Trading Post.
Your PCB is obviously an offer from a DIY person to other DIY persons. Even if you would make a few bucks per PCB it would not pay the hours you spend on this project.
If you really wish it can be done but I suggest you wait for any reactions to you concerning your "commercial" activities.
Your PCB is obviously an offer from a DIY person to other DIY persons. Even if you would make a few bucks per PCB it would not pay the hours you spend on this project.
If you really wish it can be done but I suggest you wait for any reactions to you concerning your "commercial" activities.
Saying from India:
When you're hunting a tiger you don't worry about the mosquitos
You're doing a great job Pedja.
Please don't be discouraged by these small minded people.
I really appreciate this service that you are offering us
regards
mike
When you're hunting a tiger you don't worry about the mosquitos
You're doing a great job Pedja.
Please don't be discouraged by these small minded people.
I really appreciate this service that you are offering us
regards
mike
Pedja,
I am saddened that the noise from some individuals has caused you to want to retreat. Of course the choice is yours, but there really is no need. That citisism comes from individuals incapable of doing what you do, and who wish to spoil it for everyone else - producer or user.
Many people wil benefit from your effort, I for one wish to thank you for all your work so far.
Regards,
I am saddened that the noise from some individuals has caused you to want to retreat. Of course the choice is yours, but there really is no need. That citisism comes from individuals incapable of doing what you do, and who wish to spoil it for everyone else - producer or user.
Many people wil benefit from your effort, I for one wish to thank you for all your work so far.
Regards,
Did I miss something? I agree that you should not 'change your course' on this project Pedja.
If people think that it is something professional may be that is just due to their mis-interpretation of the professional way that you go about your work. 😉
I actually chose the look of Decibel Dungeon to give the impression of it being a hobby site rather than something more professional. Having said that, I can't see anything on Pedja's site to suggest that he is making money from his hi-fi projects although the look of the site is very 'professional'.
Keep the thread where it is and let those who don't like it stick to the other threads! 😡
If people think that it is something professional may be that is just due to their mis-interpretation of the professional way that you go about your work. 😉
I actually chose the look of Decibel Dungeon to give the impression of it being a hobby site rather than something more professional. Having said that, I can't see anything on Pedja's site to suggest that he is making money from his hi-fi projects although the look of the site is very 'professional'.
Keep the thread where it is and let those who don't like it stick to the other threads! 😡
Pedja,
I can honestly say that I have never ever once entertained the notion that you have been in this for any other reason than for your own satisfaction/experience and your desire to share with others less able/talented than yourself (such as me!).
I wasnt aware that anyone had a problem with this thread, nor do i see how someone would. But I do understand your trepidation given the current climate towards such things from certain quarters. Wherever you decide to continue the project I will continue to follow it with interest, and will still almost certainly wish to purchase 1/2 boards.
I can honestly say that I have never ever once entertained the notion that you have been in this for any other reason than for your own satisfaction/experience and your desire to share with others less able/talented than yourself (such as me!).
I wasnt aware that anyone had a problem with this thread, nor do i see how someone would. But I do understand your trepidation given the current climate towards such things from certain quarters. Wherever you decide to continue the project I will continue to follow it with interest, and will still almost certainly wish to purchase 1/2 boards.
First, thanks all for the kind words.
I am not stopping the project or change anything about the project itself. I will continue with it as planned but moving it from this thread.
It is not the first time I have this intention, so in that regard my decision is not fresh. I would really like to see this thread closed.
I am not gonna leave this place.
I know there are smart enough people that can understand if I wanted to come across the money I could choose more effective ways.
I am glad to see I am not seen like businessman, but once, who knows, project may be that successful so I become wealthy with it? If I will, will I then, looking back, be understood as a forum abuser or spoiler?
John, I think you mentioned the thing that is important. Not because this project of mine is that monumental so anyone would be concerned about it, but continued strikes to some important projects here are the things that can be caused either by some ones else’s interests or insanity. No third option, but these two should be revealed and we probably came to the point where this topic probably deserves its own thread.
I think we have at the moment messy situation, but it is not because the forum is badly managed, quite opposite, I believe it is managed excellently. This messy situation is induced (provoked, motivated, forced) and my will to close this thread is an effort to clean the things.
Pedja
I am not stopping the project or change anything about the project itself. I will continue with it as planned but moving it from this thread.
It is not the first time I have this intention, so in that regard my decision is not fresh. I would really like to see this thread closed.
I am not gonna leave this place.
I know there are smart enough people that can understand if I wanted to come across the money I could choose more effective ways.
I am glad to see I am not seen like businessman, but once, who knows, project may be that successful so I become wealthy with it? If I will, will I then, looking back, be understood as a forum abuser or spoiler?
John, I think you mentioned the thing that is important. Not because this project of mine is that monumental so anyone would be concerned about it, but continued strikes to some important projects here are the things that can be caused either by some ones else’s interests or insanity. No third option, but these two should be revealed and we probably came to the point where this topic probably deserves its own thread.
I think we have at the moment messy situation, but it is not because the forum is badly managed, quite opposite, I believe it is managed excellently. This messy situation is induced (provoked, motivated, forced) and my will to close this thread is an effort to clean the things.
Pedja
Hello, Pedja.
Hope everything will proceed and my first DIY DAC will be yours one.
About transformers. I'm already tried ones taken from the old microfones (~1965 year) and they sounds good, but for shure the better idea is to visit for example mr. SOWTER site http://www.sowter.co.uk/ . Contact him - he will answer all your questions in the presence of.
About AD844. Did you ever tried AD811 instead? Although (generally) I dont like the sound of AD chips - this ones work very good in I/V stages.
About holes for capacitors. I have Evox Rifa PHE425 precision polypropylene pulse capacitors and they are for 5 mm between "legs", so, please, make just for two sizes - 15 mm and 5 mm... 🙂 Joke! This is neverending story so leave it as is.
Best regards,
Valery.
P.S. Signed me on two boards, please
Hope everything will proceed and my first DIY DAC will be yours one.
About transformers. I'm already tried ones taken from the old microfones (~1965 year) and they sounds good, but for shure the better idea is to visit for example mr. SOWTER site http://www.sowter.co.uk/ . Contact him - he will answer all your questions in the presence of.
About AD844. Did you ever tried AD811 instead? Although (generally) I dont like the sound of AD chips - this ones work very good in I/V stages.
About holes for capacitors. I have Evox Rifa PHE425 precision polypropylene pulse capacitors and they are for 5 mm between "legs", so, please, make just for two sizes - 15 mm and 5 mm... 🙂 Joke! This is neverending story so leave it as is.
Best regards,
Valery.
P.S. Signed me on two boards, please
Hi Pedja,
Just found this board and it rekindled my interest in building stuff. I would like to build your design as my first dac project .
Please sign me up for 1 board.
Great work.
🙂
Just found this board and it rekindled my interest in building stuff. I would like to build your design as my first dac project .
Please sign me up for 1 board.
Great work.
🙂
Pedja, are we to understand that you will not be posting updates on your progress on your own board on this forum?
If you feel you have to close the wikki for the group buy, that's one thing, but you should continue on posting on this thread as your DAC is a DIY effort and not a commercial product.
Best Regards
Anthony
If you feel you have to close the wikki for the group buy, that's one thing, but you should continue on posting on this thread as your DAC is a DIY effort and not a commercial product.
Best Regards
Anthony
I might probably behave professionally, i.e. ignore the rush (<- weak word) and keep going as long as someone knocks me directly. Hmm, maybe professionalism includes ignoring it especially then… But…
I just saw here really enormous quantity of mental illness and stupidity these days. Seems like it decreases now. Sad to see the people using this forum as a therapy.
If someone wants to change something in the Wiki page let do it in the next day or two, then I will save the page and delete it from the Everything Else Wiki start page, which will be, I guess, enough to make it practically invisible. All the previous signs up, either they are in the Wiki page, this thread or are sent to me by mail will be taken into account. This thread could proceed to discuss solely technical issues. If one is interested for the board, let e-mail me directly.
If anyone has the problem with this thread for any clear and normal reason, let me (or moderators or Jason or... Lumenlab or... anyone) know ASAP.
Pedja
PS: This is not the option I propose like the rule, I understand that the others could and should have their own options. Though I, normally, like a spectator, like some options less and like some options more. The_man_from_Mars option I still don’t like at all.
I just saw here really enormous quantity of mental illness and stupidity these days. Seems like it decreases now. Sad to see the people using this forum as a therapy.
If someone wants to change something in the Wiki page let do it in the next day or two, then I will save the page and delete it from the Everything Else Wiki start page, which will be, I guess, enough to make it practically invisible. All the previous signs up, either they are in the Wiki page, this thread or are sent to me by mail will be taken into account. This thread could proceed to discuss solely technical issues. If one is interested for the board, let e-mail me directly.
If anyone has the problem with this thread for any clear and normal reason, let me (or moderators or Jason or... Lumenlab or... anyone) know ASAP.
Pedja
PS: This is not the option I propose like the rule, I understand that the others could and should have their own options. Though I, normally, like a spectator, like some options less and like some options more. The_man_from_Mars option I still don’t like at all.
Valery,
I checked Sowter’s site but other than 1.2:1 unit of 6MHz bandwidth I have not seen anything appropriate.
Honestly, I have not tried AD811, but note that this DAC’s I/V stage is not a classic opamp I/V. Some time ago I settled not to use feedback in the I/V stage. I was not impressed by the capabilities of AD844 used classic way either, there are better solutions. Fortunately, this chip gives the possibility to be used open loop.
Again, if anyone thinks opamp is better way (low THD, input impedance and stuff), any applicable single opamp can be normally used. In the previous version I even put the pads for the feedback resistor (those beside pins 2 and 6 were for this) but now gave up of them trying to lower strayed capacitances (though I honestly do not believe this very moment is crucial…). It can be anyway mounted directly to the chip pins.
Btw, I put one time the pads for 12.5mm lead spaced caps also, but I guess there won’t be a lot of those who will actually use such units and 10 and 15mm is a lot of choice. 😉 Btw, are PHE425 similar to PHE426? A few PHE426 units will fit in 10mm pads.
Pedja
I checked Sowter’s site but other than 1.2:1 unit of 6MHz bandwidth I have not seen anything appropriate.
Honestly, I have not tried AD811, but note that this DAC’s I/V stage is not a classic opamp I/V. Some time ago I settled not to use feedback in the I/V stage. I was not impressed by the capabilities of AD844 used classic way either, there are better solutions. Fortunately, this chip gives the possibility to be used open loop.
Again, if anyone thinks opamp is better way (low THD, input impedance and stuff), any applicable single opamp can be normally used. In the previous version I even put the pads for the feedback resistor (those beside pins 2 and 6 were for this) but now gave up of them trying to lower strayed capacitances (though I honestly do not believe this very moment is crucial…). It can be anyway mounted directly to the chip pins.
Btw, I put one time the pads for 12.5mm lead spaced caps also, but I guess there won’t be a lot of those who will actually use such units and 10 and 15mm is a lot of choice. 😉 Btw, are PHE425 similar to PHE426? A few PHE426 units will fit in 10mm pads.
Pedja
Pedja, how will you be notifying the interested parties in the successful completion of your revised DAC?
Regards
Anthony
Regards
Anthony
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