Hi,
I would largely agree, plus it is trivial to compenate this, if desired (stopped bitclock operation, **** register delay to 2nd DAC etc... All it needs is a handfull of 74HCT logic.
You are correct, guilty as charged...
I had actually typed a longer comment on this but the dog ate it.
Ciao T
I would largely agree, plus it is trivial to compenate this, if desired (stopped bitclock operation, **** register delay to 2nd DAC etc... All it needs is a handfull of 74HCT logic.
You are correct, guilty as charged...
I had actually typed a longer comment on this but the dog ate it.
Ciao T
I think metrum use some sort of industrial (read non-audio) high speed Vout dac, several in parallel for their other offering, one would presume they have followed a similar tack for the mini.
With headphones you think this delay in inconsequencial ?
I wasn't reffering to you personally sorry you took it that way. I was just saying to look around for an authentic TDA1541 they are very attainable no need for fear mongering.
The K rated PCM56 which is the grade to sensibly considered has been discontinued, for all PCM56 it says right on ti website "NRND: This product is not recommended for new designs. However, the device, tool, or software continues to be in production to support existing customers. TI does not recommend using this part in a new design. TI encourages designers to consider alternative products for new designs." That means its done, mouser and digikey no longer sell the PCM56k.
The idea you dropped that all TDA1541x's available are becoming counterfeit or unattainable is absolutely absurd. Thread Police? is this not a TDA5141 thread, please lets move on and no need for personal attacks.
Hi,
I would largely agree, plus it is trivial to compenate this, if desired (stopped bitclock operation, **** register delay to 2nd DAC etc... All it needs is a handfull of 74HCT logic.
You are correct, guilty as charged...
I had actually typed a longer comment on this but the dog ate it.
Ciao T
Thorsten I saved that on a notepad file years ago as it was very eye-opening, sorry I didn't remember who put it together but I did say it was a quote from a tda1541 expert at least I remembered that
.
No, I don't think the linear-phase offset of the 11uS delay is consequential for headphones, where the whole listening experience is devoid of a natural image perspective anyhow, pleasurable as it may be in it's artificiality. In addition, as Thorsten points out, correcting the delay is a trivial matter in terms of the logic gates required.
Apology accepted.
I did no such thing as to suggest all TDA1541A are becoming counterfeit. What I did was open the issue of the increasing scarcity, not impossibility, of obtaining devices. The notion that the availability of a chip last manufactured nearly 20 years ago, and what John Brown sees as the next best alternative, is somehow off topic seems an oddly myopic view.
Yes, I couldn't agree more about the personal attacks. May I suggest that you refrain from initiating them in the future.
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Hi,
I would largely agree, plus it is trivial to compenate this, if desired (stopped bitclock operation, **** register delay to 2nd DAC etc... All it needs is a handfull of 74HCT logic.
You are correct, guilty as charged...
I had actually typed a longer comment on this but the dog ate it.
Ciao T
Should the dog ever vomit it back up I would be interested to read any futher thoughts you had on that, or any unpublished thoughts you have on any aspect of DAC design, Thorsten. Usually is interesting reading, as are John's thoughts regarding DAC design.
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Hi,
I'll see if I find the time.
TBH, personally I would probably do a hybrid DAC, not dissimilar to the Ultra Analog stuff, with a discrete DAC in an FPGA plus suitable bitswitches and reference sources for the upper maybe 8 Bits and an integrated DAC like that TI DAC8580 for the lower maybe 16 Bits (and no, I see absolutely no point in 32 bit DAC's).
Ciao T
I'll see if I find the time.
TBH, personally I would probably do a hybrid DAC, not dissimilar to the Ultra Analog stuff, with a discrete DAC in an FPGA plus suitable bitswitches and reference sources for the upper maybe 8 Bits and an integrated DAC like that TI DAC8580 for the lower maybe 16 Bits (and no, I see absolutely no point in 32 bit DAC's).
Ciao T
Hi FRUGIVO,
Nice solder work, but I have some remarks,
Try to keep ALL connections as short as possible, every millimeter really counts. The resistive attenuators (4K7 and 2K2) only work reliably with very short interlinks between attenuator and DAC chip (capacitive loading).
Mount all circuits on a ground plane like the copper side of a piece of PCB material.
Try to keep incoming I2S signals well separated (crosstalk), you could use flat cable with following arrangement: GND, DATA, GND, WS, GND, BCK, GND
Datasheet DEM clock configuration leads to low performance due to inter-modulating clocks (on-chip crosstalk) between free running DEM clock and I2S timing signals. It's better to synchronize the DEM clock with BCK (2.8224 MHz) when using NOS.
The DEM clock can also be synchronized on multiples of WS when fine tuning the value of the external timing cap. Locking can be checked using an oscilloscope. Keep in mind that this type of synchronization is instable and locking can be lost with varying chip temperature.
I stopped using ceramic SMD caps a while ago after I experienced problems with reliability and performance. I now use SMD film caps exclusively.
Nice solder work, but I have some remarks,
Try to keep ALL connections as short as possible, every millimeter really counts. The resistive attenuators (4K7 and 2K2) only work reliably with very short interlinks between attenuator and DAC chip (capacitive loading).
Mount all circuits on a ground plane like the copper side of a piece of PCB material.
Try to keep incoming I2S signals well separated (crosstalk), you could use flat cable with following arrangement: GND, DATA, GND, WS, GND, BCK, GND
Datasheet DEM clock configuration leads to low performance due to inter-modulating clocks (on-chip crosstalk) between free running DEM clock and I2S timing signals. It's better to synchronize the DEM clock with BCK (2.8224 MHz) when using NOS.
The DEM clock can also be synchronized on multiples of WS when fine tuning the value of the external timing cap. Locking can be checked using an oscilloscope. Keep in mind that this type of synchronization is instable and locking can be lost with varying chip temperature.
I stopped using ceramic SMD caps a while ago after I experienced problems with reliability and performance. I now use SMD film caps exclusively.
As usual we need to thanks John for his generosity to share his work!!
If I understand correctly, the common-mode regs posted in 3978 have now been replaced by the ones in the main schematics plus the ones in the main power supply of the dac?
Also, I thought you were using air-coil inductors... now I see a center-tap connected to GND?
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why is that? 32 bits used for just audio, i agree with you, but 32 bit dac chips allow filters, volume etc to be calculated with far better accuracy and be more 'out of the way'
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While I obviously can't speak for Thorsten, I do suspect that he is referring to the actual converter resolution, not necessrily the digital signal processing which comes before. However, even if we only consider the digital processing side of a DAC being performed with 32-bit precision, ultimately, the data will likely be dithered down to the converter's resolution, which won't reach a true 24-bits much less 32-bits.
Even should we leave the data un-dithered at 32-bits, the converter technology is still limited to a real dynamic range well short of the 24-bit level. All of which strongly argues that attempts at 32-bits processing anywhere in the DAC is major overkill, being more of a marketing than an engineering driven initiative.
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yeah i thought perhaps he was too thus the question, i would agree with him if that was the case, but if not i strongly disagree. i'm fairly specifically talking about the 32bit dacs by ESS and CS (now also Ti but i dont have any experience or first hand knowledge of them), both of which have integrated filters and volume control that operate even higher than 32bit (but the dac is also 32bit). the 32bit audio file format being used in todays DAWs is used for the same reason, so volume control and filter info can be transported along with the audio and multiple tracks mixed live without as much fear of a musician or engineer overdriving one track and ruining the whole mix. overall rather useful imo
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thanks john
try to follow your recommendations to the maximum possible
I am using synchronize DEM
if you look at the circuit has two bases with four d flip-flop
I find it hard to get distributor for SMD film caps
but I hope to get soon
I want to try and hear how it sounds this improvement
Hi,
Have you ever calculated the practical (not theoretical) dynamic range of a recording microphone recording a real performance in a minimalist arrangement (I am not interested in "Music freshly created completely artificially and without any human involvement in our multi million dollar laboratory")?
Ciao T
Have you ever calculated the practical (not theoretical) dynamic range of a recording microphone recording a real performance in a minimalist arrangement (I am not interested in "Music freshly created completely artificially and without any human involvement in our multi million dollar laboratory")?
Ciao T
did you completely miss the point of my post? ie headroom for recording of real or not so real live instruments in the world of real imperfect live recording situations?. headroom for superior multitrack volume control? headroom so that a moment in time in a performance is not lost forever due to an accidentally overdriven channel?
dont answer that, your age and prejudice is showing. there are some absolutely superb models of real instruments too these days, also 32 and 64bit captured cathedral reverb tails are sublime. i dont know about you, but i dont generally have access to one of these venues whenever i want
it must be nice living with this simplistic view on what constitutes real music and real musicians, me thinks you need to broaden your horizons. i dont like being pigeon holed and i doubt the real musicians you have so completely dismissed would like it either.
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Recloker and synchronize DEM
My first impression is very positive
more than I expected
more refined sound throughout the audio spectrum
more transparent sound
could say that the improvement reaches 30%
I'll have to listen again to all cd, s
john thanks for your unconditional way of seeing things and keep restless
TDA 1541 and VCXO POWERED WITH WITH LITHIUM BATTERY
My first impression is very positive
more than I expected
more refined sound throughout the audio spectrum
more transparent sound
could say that the improvement reaches 30%
I'll have to listen again to all cd, s
john thanks for your unconditional way of seeing things and keep restless
An externally hosted image should be here but it was not working when we last tested it.
TDA 1541 and VCXO POWERED WITH WITH LITHIUM BATTERY
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Hola Galeb
lo de negro es un pack de baterias de litio recargables
+7-tda
-7-tda
-16-tda
+4 -vcxo
+4-dem
saludos
