These things are of less importance.
You need a 1541 and its supplies plus some output stage. Then you'd like to feed it with i2s taken out of anamero board as it has xtals in place. Use of isolator board is rather doubtful as long as you don't have any ground loop problems with pc. It will emit more noise than it will isolate plus add jitter.
The drive nos board is not required in 1541 case if tdas format matches anameros. Less stuff in between means less noise and jitter. Use a single ff on bclk fed with mclk of anamero board.
Then you've got T's guidelines to go.
Don't use spdif without back syncronization -it is flawed by design.
Buy a ton of ferrite wire clamps.
Make all digital connections propertly with transmission lines in mind.
You need a 1541 and its supplies plus some output stage. Then you'd like to feed it with i2s taken out of anamero board as it has xtals in place. Use of isolator board is rather doubtful as long as you don't have any ground loop problems with pc. It will emit more noise than it will isolate plus add jitter.
The drive nos board is not required in 1541 case if tdas format matches anameros. Less stuff in between means less noise and jitter. Use a single ff on bclk fed with mclk of anamero board.
Then you've got T's guidelines to go.
Don't use spdif without back syncronization -it is flawed by design.
Buy a ton of ferrite wire clamps.
Make all digital connections propertly with transmission lines in mind.
Looks like so erin, thank`s.
I thought so i take the Amanero USB to I2S http://www.diyaudio.com/forums/vendors-bazaar/216474-usb-i2s-384khz-dsd-converter.html
And the "Amanero Isolator/Reclocker" http://www.diyaudio.com/forums/group-buys/227502-amanero-isolator-reclocker-gb.html
Should i take the board too?http://www.diyaudio.com/forums/digital-line-level/220407-drive-nos-ad1865-62-pcm1704-02-63-tda1541-fifo-universal-i2s-pcm-driver-board.html
Hmm, Im really not sure the first two boards are going to be suited to TDA1541A.
The Amanero USB board, outputs 32 bit data, and from what I can tell ( I admit I didn't check it out very thoroughly) has no option to switch to 16 bit. Or am I wrong? Perhaps the option is controlled by the PC music software?
I only mention this because IMO the TDA1541A looses some of its "je ne sais quoi" when running with 24 bit data.
The isolator board will add some jitter to your signal, and Im not really sure why anyone would want to isolate their i2s, if their board is designed properly
The Universal I2S-PCM driver board will enable you to make a fully balanced TDA1541A DAC board. which is what I thought you were inquiring about?
Though no matter which way you build it will have a compromise of one sort or another. Most of the people getting excited about the first two mentioned boards, are using modern
DAC chips.
But each to their own.
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Getting the data from the transport to the DAC chip has always been the issue.
Do you think that recovering the clock in the SPDIF signal is more or less troublesome than recovering the clock from the USB signal (and I'm talking about clock recovery in terms of the sound, not talking about operating a printer, because clearly USB works, but SPDIF also works)?
You must take into account that the cheaper USB spdif/ i2s converters use a single frequency crystal to generate the clock, and 48khz is usually the "native" frequency, which does not suit when playing 44.1khz material, and the more expensive ones tend to use two clocks for generating the various frequencies.
On the two units I have compared i2s vs SPDIF I was not really sold that i2s was any better at all, because wires have to be soldered from the board supplying the i2s to the DAC board, and getting the wire length, and spacing correct is almost impossible with "flying"" wires.
But I also admit that SPDIF is also very fussy to get sounding its best.
In theory the best audio transport would send the data straight off the HDD/ SSD / memory, using i2s directly to the DAC, without an intermediate conversion device? And this brings us back to a CD player. LOL. But we don't want to use those anymore, so we must use a "computer", because the "media players" unfortunately do not sound as good as a "computer". Perhaps in 5 years time things will change
Your thoughts?
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And this brings us back to a CD player. LOL. But we don't want to use those anymore, so we must use a "computer", because the "media players" unfortunately do not sound as good as a "computer". Perhaps in 5 years time things will change
Your thoughts?
Exactly, and this is why the FiFO + daughter PCB is so exciting, no way I am going back to an CDP disguised as an SD "transport". With the fifo and the daughter board finally true 16 bit original I2S, one can do a sinx/x compensation via computer, or oversample if desired, or listen to an album on one of thier 3TB drives.
But the question still remains, is there a good TDA1541 PCB?
There was one version of the ecdesigns that would have been perfect, but he quit selling it. So at the moment there really isn't anything with even basic proper decoupling. The Thorsten bug board with ground plane looks to be the way to go. Until someone more talented than I makes a good multi-layer PCB (all we need is the deem, and decoupling, just leave the output stage off of it as no one has a perfect output stage anyhow.)
Hmm, Im really not sure the first two boards are going to be suited to TDA1541A.
The Amanero USB board, outputs 32 bit data, and from what I can tell ( I admit I didn't check it out very thoroughly) has no option to switch to 16 bit. Or am I wrong? Perhaps the option is controlled by the PC music software?
I only mention this because IMO the TDA1541A looses some of its "je ne sais quoi" when running with 24 bit data.
The isolator board will add some jitter to your signal, and Im not really sure why anyone would want to isolate their i2s, if their board is designed properly
The Universal I2S-PCM driver board will enable you to make a fully balanced TDA1541A DAC board. which is what I thought you were inquiring about?
Though no matter which way you build it will have a compromise of one sort or another. Most of the people getting excited about the first two mentioned boards, are using modern
But each to their own.
I2s as specified by Philips use 64bit frames containing two 32bit words corresponding to left and right.
The 1541 will just ignore any bits past the sixteen most significant. Of course if you feed it with 24bit data anyway and don't dither it properly you will experience truncation.
there is more than ground loop problems to worry about, I dont know which isolator board you are talking about, one has integrated reclocking (which can be sourced from whatever clock source you wish) the other doesnt. the only added jitter is that of the flip flop if you are prudent where you pull the clock from.
Getting the data from the transport to the DAC chip has always been the issue.
Do you think that recovering the clock in the SPDIF signal is more or less troublesome than recovering the clock from the USB signal (and I'm talking about clock recovery in terms of the sound, not talking about operating a printer, because clearly USB works, but SPDIF also works)?
You must take into account that the cheaper USB spdif/ i2s converters use a single frequency crystal to generate the clock, and 48khz is usually the "native" frequency, which does not suit when playing 44.1khz material, and the more expensive ones tend to use two clocks for generating the various frequencies.
On the two units I have compared i2s vs SPDIF I was not really sold that i2s was any better at all, because wires have to be soldered from the board supplying the i2s to the DAC board, and getting the wire length, and spacing correct is almost impossible with "flying"" wires.
But I also admit that SPDIF is also very fussy to get sounding its best.
In theory the best audio transport would send the data straight off the HDD/ SSD / memory, using i2s directly to the DAC, without an intermediate conversion device? And this brings us back to a CD player. LOL. But we don't want to use those anymore, so we must use a "computer", because the "media players" unfortunately do not sound as good as a "computer". Perhaps in 5 years time things will change
Your thoughts?
As long as there are two dedicated audio frequency xtals on the USB board - it means there is no clock recovery of any sort.
These USB boards aint that pricey anymore...
PCM240X, Tenors - did the clock recovery thus they were as bad as SPDIF if not worse.
If you have reclocker, oscillator and DAC directly connected, then you get the same performance as CD - it works in the same way no matter where it takes that data.
As been mentioned before by Tazzz, TDA worked flawlessly with 64Fs BCLK (32 bit I2S or whatever you may call it), up to 96kHz. For decades.
Well, AFAIK there is no plans of shaving-off the oscillators from anamero's board and feeding the USB board with two external clocks thru extra isolators. Anamero doesn't support slaved operation from it's I2S port (again, AFAIK).
So, the only clock source you can use to reclock FFs is that of anamero's board. You may feed it thru the isolator and get jitter, or you can feed it without isolator thus rendering the isolator thing useless.
We're not talking bout that silly quirk of reclocking the signal with free running oscilator, ain't we?
* Yes, there are more than ground loop problems to worry...
1 - Isolators produce noise /they really do so, common mode for each side = differential between isolated sides. it's hard to get rid of it/
2 - Proper implementation of isolator's layout from the app note connects both sides of isolated circuits thru capacitance rendering the isolation useless on HF = just a ground isolation. Without following the app note you get a nice noise source as per 1.
Due to ground bounce, I suspect feeding TDA1541 with extra data bits will create additional current pulses which wont be optimal for this 16 bit chip. I am aware that the additional bits will be "ignored" Anyone want to comment?
But what about all those "flying" wires required to hook it up, Picking up noise? If it is built all-in-one on the DAC PCB, its probably good, but, if the i2s isolation is on the DAC PCB then you wouldn't need isolation anyway, would you? what exactly are we trying to isolate that can't be done by other methods?
Ok, but then you have the issue of xtal quality. Many people have reported that when you improve the oscillator design, or improve the power supply to the xtal then you get better sound. So, clock generation is still an issue.
It seems to come down to the clock yet again.
And what if you are using a Wolfson WM8805 with its crystal clock recovery?
What I am suggesting is that most people who are using these boards are tacking them on to an existing design. The more boards, the more issues with power supplies, and flying wire connections.
It just seems to me like swapping one lot of issues for another lot.
Most DIY'ers are hobbyists, not professionals. Getting everything connected optimally for them is going to be challenging at best.
It just seems to me like swapping one lot of issues for another lot.
Most DIY'ers are hobbyists, not professionals. Getting everything connected optimally for them is going to be challenging at best.
you havent even looked at the design i'm talking about have you? or at least you havent understood it. it uses u.fl connectors, like fifo, like the board presented in this thread, like anyone listening to the community and testing should be and it plugs directly onto amanero. no flying wires required. there is room for a couple control signals on the board too, amanero has functionality you arent aware of.... isolated control signals to tell clocks to change are completely doable, no need to use the amanero clocks at all
oh I wasnt aware you were catering only for the lowest common denominator that doesnt know how to use the things they buy.....
oh I wasnt aware you were catering only for the lowest common denominator that doesnt know how to use the things they buy.....
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user manual comes with purchase, patience will be required for that, its sold as PCB only so you cant expect too much. it also has decent onboard regulation for both sides. input side can take a 5v from amanero, the output side should take power and ground from the destination. There is not much current needed on the output side, so taking it from the pre-reg supplying the clocks should be doable, that will keep loop area at that end to a minimum.
it was only intended as a small GB to get the price down a bit for production, response was well beyond expectations. There will without a doubt be people who bought it who have not much idea how to use it, but thats par for the course here these days.
it was only intended as a small GB to get the price down a bit for production, response was well beyond expectations. There will without a doubt be people who bought it who have not much idea how to use it, but thats par for the course here these days.
Ok. Thank you. I presume using u.fl connectors for i2s connections necessitates the user to design a bespoke DAC PCB to interface with this board?
Is there a proper way to retrofit u. fl connectors to an existing board? Seems a bit tricky. The other thing that interests me is that they are a 75ohm controlled impedance connector, so does this mean you need terminating resistors on your i2s lines?
Is there a proper way to retrofit u. fl connectors to an existing board? Seems a bit tricky. The other thing that interests me is that they are a 75ohm controlled impedance connector, so does this mean you need terminating resistors on your i2s lines?
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If those extra bits are not zero the implementation is wrong... or at least not optimal.
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Where can more information be found about these undocumented features in the amanero?
I have the anamero in front of me, with schematics. There is no manual nor any mention of slaved operation.
Oh, I may write my firmware for cpld, that's interesting! I need to reverse engineer the communication between mcu and cpld first, yet cpld is 32 cell device, should be an easy task. Then I'll be able to implemeent a bit of "drive nos" thing in the board, with extra bit reductions etc.
Sounds like a fun project!
Oh, I may write my firmware for cpld, that's interesting! I need to reverse engineer the communication between mcu and cpld first, yet cpld is 32 cell device, should be an easy task. Then I'll be able to implemeent a bit of "drive nos" thing in the board, with extra bit reductions etc.
Sounds like a fun project!
they are 50ohms, 75ohms is for external use, nobody uses 75ohms for i2s or even spdif internally. there are already a number of boards using ufl connectors, nothing so far that uses ancient dacs though
there is a partial design in this thread for a TDA1541A that has them optional to use with fifo, but development seemed to stall.termination will depend on the board (thickness and trace-width ie characteristic impedance), some will have it at the sending end, some will have at the receive end, its rarely 50ohms though, normally 22-33ohms is used.
Tazzz, its not documented anywhere, but its there on the board, how else does it select its own clock? the designer has put quite a few extra functions in the firmware editor, i'd say with a bit of ingenuity the clock select signal could be tapped or even sent on the DSDOE pin. ask the designer, I have no need for it so no help from me i'm afraid. he has been forthcoming with some changes and there is definitely undocumented features and control, but no hand holding =)
s3tup, I believe you are on the right track =) remember its also available as a chipset for OEM, there has to be backdoors or even front doors to access this stuff, you may not even need to rewrite anything
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Perhaps you would be kind enough to explain why a person would not use a 50 ohm resistor in this application? Is it to do with the short length of wire?
because there are other elements that contribute to the series impedance, some do use 50ohms but its pretty rare these days and as I mention in the part you quoted, its not hard and fast, different flip flops, logic, different PCB thickness, different trace thickness (both of which define the line impedance), different impedance that may already be at the sending end, the speed of the connection, rise time etc. its on a case by case basis, but 50 ohms is less likely.
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