The problem is just there, one should be careful before claiming such that statement.
I wonder how a little DAC board with cheap components and questionable design choices can achieve the performance of a 3-chassis DAC such as the MSB.
There is something wrong.
I can't afford a MSB DAC so we are trying to develop something similar at lower price for us and maybe for the audio community.
But we don't expect to get the same results for EUR 350 and a little board, we expect to invest at least one order of magnitude more than the DAM price and we are planning a 3/4 chassis DAC.
But my mind is open so I'm here to understand the technical reasons why the DAM could achieve the performance of the MSB DAC.
I hope someone could explain.
The relevance of low phase noise of the clock for a DAC's performance and the transparency of the DAM1021's FIFO are two completely seperate issues that shouldn't be confused.
Regarding the former I have no idea, but I have ordered a clock from Andrea and will use it in a SAR ADC and report back. I hope it does improve performance, of course.
As for the latter, there are easily and reproduceably different outcomes depending on clocking. Before I had the RS-422 receivers added to the DAM1021 input I used the S/PDIF schematic shown in the manual. This was even more reliant on the source, and changing from S/PDIF level to AES/EBU level very audibly changed the outcome. Changing the digital input's grounding arrangement changed the outcome. No dropouts, just sound differences.
I am quite happy with the way the DAM1021 sounds on the RME card's internal clock, but I cannot use that clock in a multi card multi channel studio setup.
The DAM1021's drift is - again - a different issue. Well maybe more input jitter forces more corrections, in this case there could be a relation.
I hope it can be resolved soon, since the promise of "absolute best" so far has not been fullfilled.
Regarding the former I have no idea, but I have ordered a clock from Andrea and will use it in a SAR ADC and report back. I hope it does improve performance, of course.
As for the latter, there are easily and reproduceably different outcomes depending on clocking. Before I had the RS-422 receivers added to the DAM1021 input I used the S/PDIF schematic shown in the manual. This was even more reliant on the source, and changing from S/PDIF level to AES/EBU level very audibly changed the outcome. Changing the digital input's grounding arrangement changed the outcome. No dropouts, just sound differences.
I am quite happy with the way the DAM1021 sounds on the RME card's internal clock, but I cannot use that clock in a multi card multi channel studio setup.
The DAM1021's drift is - again - a different issue. Well maybe more input jitter forces more corrections, in this case there could be a relation.
I hope it can be resolved soon, since the promise of "absolute best" so far has not been fullfilled.
Andrea, Could you please post in your own thread, instead of polluting the dam1021 thread with you all your crap ?
This is a techincal thread about the dam1021, there are users here that are looking for useful information...
My posts are absolutely about technical aspects, just like the one you have quoted.
As a customer I would like to understand the technical reasons why the DAM could achieve the performance of the MSB DAC.
I believe with your design choices and the architecture of your device you cannot achieve the performance of the MSB DAC, but I'm here to hear your reasons.
Moreover I'm one of the users looking for useful information, I asked at least a couple of times how I can feed the ladder neetwork starting from the 595s by external source disconnecting the front end.
But it looks like I have to discover myself how to implement the tweaking since you have never replied.
As a customer I would like to understand the technical reasons why the DAM could achieve the performance of the MSB DAC.
I believe with your design choices and the architecture of your device you cannot achieve the performance of the MSB DAC, but I'm here to hear your reasons.
Moreover I'm one of the users looking for useful information, I asked at least a couple of times how I can feed the ladder neetwork starting from the 595s by external source disconnecting the front end.
But it looks like I have to discover myself how to implement the tweaking since you have never replied.
Just like a lot of other projects here, there is a target for performance, that might take some effort to meet, it is DIY after all.... And you must admit, there have been improvements since first release....
And as I have said plenty of times before, the dam1021 is what it is, if you want to change something, you're welcome, but I can't waste my time doing it for you. So don't expect me to respond to your stupid ideas.
And Andrea, please read diyAudio Rules, especially 1 and 3.
It looks like you have not read the rule number one since you are offending me: "your stupid ideas".
And it's not the first time you offend someone, you are used to this behavior, while I have never offended you.
And since "it is DIY after all", do you decide for others what can be tweaked?
Can you explain why mine is "a stupid idea"?
Do you think is it so stupid replacing a non working FIFO with a better one?
And it's not the first time you offend someone, you are used to this behavior, while I have never offended you.
And since "it is DIY after all", do you decide for others what can be tweaked?
Can you explain why mine is "a stupid idea"?
Do you think is it so stupid replacing a non working FIFO with a better one?
Suggesting an idea that is impossible in the design, or no way fit the application, IS a stupid idea. I have designed a board, with specific needs and performance in mind, if it don't fit you needs, just forgot about it and find one that fit your needs.
I cannot forget 350 Eur I paid for the board, therefore in the diy spirit I want to tweak it because I have several technical reasons to believe that the front end can be improved a lot.
You claimed the source and the DAC work in different time domains but several users tell a different story: any change in the source is clearly audible at the output.
This means that the FIFO does not work as it should.
And so replacing the FIFO is a stupid idea???
NO, it's technically speaking unexceptionable.
And please avoid writing that is impossible in the design, or no way fit the application when you well know it's not true.
The LVC595 has a shift register clock input (PCM BCK), a serial data input (PCM DATA) and a storage register clock input (PCM LRCK) and the 595s are cascaded among them.
Therefore you well know that I only need to know where I have to connect the above signals on the PCB from an external source providing the DATA in sign magnitude notation, that's exactly what my FIFO Lite does.
Maybe the ladder network needs bipolar power supply therefore I have to shift the level of the input signals. Not a problem, already done in my DAC Lite.
So where is the problem?
Don't you want to tell me?
Well, I will find them myself, I own a oscilloscope and I'm able to use it.
But thanks anyway for not helping.
Yours is just the spirit of DIY.
You claimed the source and the DAC work in different time domains but several users tell a different story: any change in the source is clearly audible at the output.
This means that the FIFO does not work as it should.
And so replacing the FIFO is a stupid idea???
NO, it's technically speaking unexceptionable.
And please avoid writing that is impossible in the design, or no way fit the application when you well know it's not true.
The LVC595 has a shift register clock input (PCM BCK), a serial data input (PCM DATA) and a storage register clock input (PCM LRCK) and the 595s are cascaded among them.
Therefore you well know that I only need to know where I have to connect the above signals on the PCB from an external source providing the DATA in sign magnitude notation, that's exactly what my FIFO Lite does.
Maybe the ladder network needs bipolar power supply therefore I have to shift the level of the input signals. Not a problem, already done in my DAC Lite.
So where is the problem?
Don't you want to tell me?
Well, I will find them myself, I own a oscilloscope and I'm able to use it.
But thanks anyway for not helping.
Yours is just the spirit of DIY.
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Andrea, we had this discussion before, nothing have changed since, so why do you repeat yourself ? And you bought the dam1021 AFTER last discussion, so what's your problem ? You knew EXACTLY what you bought...
If you have a scope, then use it, it's not a complicated board. Read the whole thread, I have revealed a lot of details....
If you have a scope, then use it, it's not a complicated board. Read the whole thread, I have revealed a lot of details....
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Soeren,
I knew what I bought and I knew I bought the DAM to measure and tweak it in the spirit of this forum.
You knew this before I bought the board, I wrote so several times.
Then I would expect the help of the seller to tweak the board since it has been presented in a diy audio forum.
I also have presented some devices on this forum and I do the best to help the members when they ask for infos in order to modify the boards
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
What is the problem to tell me how I have to connect an external FIFO to the DAM?
I knew what I bought and I knew I bought the DAM to measure and tweak it in the spirit of this forum.
You knew this before I bought the board, I wrote so several times.
Then I would expect the help of the seller to tweak the board since it has been presented in a diy audio forum.
I also have presented some devices on this forum and I do the best to help the members when they ask for infos in order to modify the boards
The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator
What is the problem to tell me how I have to connect an external FIFO to the DAM?
I don't have time, I need to assemble and ship dac2541's.... Also, it's not like you're acting to make me wanting to help you....
I looks like that you don't want to help me.
You should simply pointing me out 4 points on the PCB: BCK, DR, DL and LRCK to feed the 595s (maybe 8 points if I have to feed with bipolar signal, negative and positive rail of the ladder network).
And also the data protocol although I believe it's 27 or 28 bit MSB first.
How much time does it take?
5 minutes?
You should simply pointing me out 4 points on the PCB: BCK, DR, DL and LRCK to feed the 595s (maybe 8 points if I have to feed with bipolar signal, negative and positive rail of the ladder network).
And also the data protocol although I believe it's 27 or 28 bit MSB first.
How much time does it take?
5 minutes?
If you look 5 seconds on the PCB it should be clear that you can not do it that way - there are just to many data lines from the FPGA to the resistor ladder. Either you reprogram the FPGA for your needs or you will have to feed every 595 individually.
You are wrong, the FPGA feeds the first of the cascaded 595s then the 595s feed the ladder.
4 x 595 for each rail x 7 lines = 28 bit
Unless the 595s are fed in parallel so 4 lines for each rail (to run the DAC at crazy speed).
4 x 595 for each rail x 7 lines = 28 bit
Unless the 595s are fed in parallel so 4 lines for each rail (to run the DAC at crazy speed).
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Read my argument again. Think a minute or two before writing your replay. The red encircled area is in the very wrong area of the PCB regarding to the problem on the hand.
Again you are wrong, there are no lines from the FPGA to the resistor ladder.
All the lines are from the FPGA to the 595s (DATA, BCK and LRCK).
Have you any idea how a discrete DAC with 595s works?
All the lines are from the FPGA to the 595s (DATA, BCK and LRCK).
Have you any idea how a discrete DAC with 595s works?
Sure I do 🙂
I even bothered to trace the PCB of the DAM instead of assuming other people should do the work for me.
If you ever wonder why people are no longer keen on answering your questions ... thats a good topic to think about in the holidays.
I even bothered to trace the PCB of the DAM instead of assuming other people should do the work for me.
If you ever wonder why people are no longer keen on answering your questions ... thats a good topic to think about in the holidays.
No, you don't know how the DAC works because if you knew how it works you wouldn't wrote "many data lines from the FPGA to the resistor ladder" since there are no lines from the FPGA to the resistor ladder.
This is just the great difficult to keep technical the discussion on this forum.
One should be careful writing without the required knowledge.
This is just the great difficult to keep technical the discussion on this forum.
One should be careful writing without the required knowledge.
There are of cause some components in-between the FPGA and the resistor ladder. I assumed some understanding of the design and readiness to use your brain to follow my argument.
You are welcome!
It looks like you have to study a little about R2R discrete DAC, but don't worry, I will publish a quick paper on the forum as soon as I find the time.
It looks like you have to study a little about R2R discrete DAC, but don't worry, I will publish a quick paper on the forum as soon as I find the time.