Yes, I finally have the application notes!
And the DEMO 1 eval board paperwork and of course the original datasheet which is readily available but this time in much better quality.
Where did I get them from? I asked Daniel Weiss if he had them after discovering his BW102 studio mastering processor used some in the 20bit DAC module.
So a BIG thankyou to Daniel Weiss! A very friendly and helpful man.. even though he's also a very busy man too.
I've uploaded them to PDFcast.org so they will be searchable on there in the future and here are the download links:
UltraAnalog D20400 Application Note AP02 (pdf)
UltraAnalog DEMO 20 bit ADC - DAC Evaluation Board Datasheet (pdf)
UltraAnalog D20400 20 bit DAC Datasheet (pdf)
Have fun with those people.. I will.
Keep a look out for D20400s in old 20bit pro equipment like Philip Drake broadcast gear, Weiss BW102 mastering processor 20 bit DAC modules - there will be others.
And the DEMO 1 eval board paperwork and of course the original datasheet which is readily available but this time in much better quality.
Where did I get them from? I asked Daniel Weiss if he had them after discovering his BW102 studio mastering processor used some in the 20bit DAC module.
So a BIG thankyou to Daniel Weiss! A very friendly and helpful man.. even though he's also a very busy man too.
I've uploaded them to PDFcast.org so they will be searchable on there in the future and here are the download links:
UltraAnalog D20400 Application Note AP02 (pdf)
UltraAnalog DEMO 20 bit ADC - DAC Evaluation Board Datasheet (pdf)
UltraAnalog D20400 20 bit DAC Datasheet (pdf)
Have fun with those people.. I will.
Keep a look out for D20400s in old 20bit pro equipment like Philip Drake broadcast gear, Weiss BW102 mastering processor 20 bit DAC modules - there will be others.
Some guys must have create a schematic diagram according the opened PCB's (have a look to the images).
Maybe one of the members can upload the schema.
Maybe one of the members can upload the schema.
Attachments
I had a PS Audio Ultralink II with this dac chip in it and had lots of information on the device. I replaced it with a cheap Zhaolu 2.5A which easily trounced it even stock. Performance-wise its truly been superseded, I believe PCM1794A, several AD 24 bit stereo dacs will better it as will any of the ESS 90xx series devices.
I must be missing something. Nostalgia is great, but there have been vast improvements in dac performance in the past couple of decades.
I'd not trade my HAP-Z1ES for a set up using a dac with one of these hybrids.
It was great in its day..
I must be missing something. Nostalgia is great, but there have been vast improvements in dac performance in the past couple of decades.
I'd not trade my HAP-Z1ES for a set up using a dac with one of these hybrids.
It was great in its day..
The newer versions of this circuit are by far not outdated !
In case you knew,
that improvements of this very circuit of the D20400A (the last iteration) survived in the DA924 and Quintessence DA-N5 Studio Reference DACs from Lavry Engineering and if you are in designing discrete DACs, you may find the circuit details still quite interresting, if you could find them anywhere ...
If one would find the schematics of a DA924 DAC core section, it would certainly be even more interesting indeed !
I'm not sure about PCM1794A vs. D20400A, but I think that no Sabre/PCM1794/PCM1704 or any other monolithic DAC chip based design will beat a DA924 or a DA-N5, when it comes to certain qualities, which are related to DNL performance and at the same time low DAC intrinsic jitter (try to clock a 100ps jitter DAC chip with a 10fs super clock and you get again 100ps of jitter ...).
In order to compare such "vintage" DAC designs apples to apples, you would at least need to sample rate convert modern HD audio files to 20/44.1 while using good dithering and playing these files on the classic and the modern DAC (Which I already did with quite surprising results).
If doing so, I think, that even a D20400A based classic design (with some upgrades to the analog sections, e.g. replacing OP275 against something more modern), even your HAP-Z1ES would be in rather big danger, but only sound wise, not convenience wise ...
If you then also consider, that the D20400A may accept non-oversampling at 384kHz or 192kHz and connect it to a modern digital IO (e.g. USB interface), you could finally find out, which potential is inside such an old DAC module at 20/384 or 20/192 which is dynamics wise not worse than DSD64 at least.
I don't tell you, it could beat everything on the market today, but the comparison using an optimized 20b audio format would be quite frustrating for people, who just paid 10000 USD for their 4xPCM1794 Evaluation Kit circuit with some useless 64 bit digital PLL jitter voodoo circuitry or magic so called bit perfect digital filters ...
In case you knew,
that improvements of this very circuit of the D20400A (the last iteration) survived in the DA924 and Quintessence DA-N5 Studio Reference DACs from Lavry Engineering and if you are in designing discrete DACs, you may find the circuit details still quite interresting, if you could find them anywhere ...
If one would find the schematics of a DA924 DAC core section, it would certainly be even more interesting indeed !
I'm not sure about PCM1794A vs. D20400A, but I think that no Sabre/PCM1794/PCM1704 or any other monolithic DAC chip based design will beat a DA924 or a DA-N5, when it comes to certain qualities, which are related to DNL performance and at the same time low DAC intrinsic jitter (try to clock a 100ps jitter DAC chip with a 10fs super clock and you get again 100ps of jitter ...).
In order to compare such "vintage" DAC designs apples to apples, you would at least need to sample rate convert modern HD audio files to 20/44.1 while using good dithering and playing these files on the classic and the modern DAC (Which I already did with quite surprising results).
If doing so, I think, that even a D20400A based classic design (with some upgrades to the analog sections, e.g. replacing OP275 against something more modern), even your HAP-Z1ES would be in rather big danger, but only sound wise, not convenience wise ...
If you then also consider, that the D20400A may accept non-oversampling at 384kHz or 192kHz and connect it to a modern digital IO (e.g. USB interface), you could finally find out, which potential is inside such an old DAC module at 20/384 or 20/192 which is dynamics wise not worse than DSD64 at least.
I don't tell you, it could beat everything on the market today, but the comparison using an optimized 20b audio format would be quite frustrating for people, who just paid 10000 USD for their 4xPCM1794 Evaluation Kit circuit with some useless 64 bit digital PLL jitter voodoo circuitry or magic so called bit perfect digital filters ...
what about this replacement under
PCX DAC Module Replacement for Ultra Analog ?
more URLs to this topic:
Digital Drive
ultra analog D20400A dac ideas
Climbing the ladder | PS Audio
http://www.diyaudio.com/forums/vendor-s-bazaar/202816-ultra-analog-d20400a-krell.html#post5430636
https://www.stereo.net.au/forums/topic/110550-new-holo-audio-spring-dac-r2r-and-dsd/?page=8
http://www.gammaelectronics.xyz/stereoph_4-1996_Parasound-DACs.html
PCX DAC Module Replacement for Ultra Analog ?
more URLs to this topic:
Digital Drive
ultra analog D20400A dac ideas
Climbing the ladder | PS Audio
http://www.diyaudio.com/forums/vendor-s-bazaar/202816-ultra-analog-d20400a-krell.html#post5430636
https://www.stereo.net.au/forums/topic/110550-new-holo-audio-spring-dac-r2r-and-dsd/?page=8
http://www.gammaelectronics.xyz/stereoph_4-1996_Parasound-DACs.html
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Another application note here: http://forum.vegalab.ru/attachment.php?attachmentid=239526&d=1434311729
Which DAC chips did you use PCM1702 ?
EDIT: Zoom into picture reveals it's PCM1704
Is it your development ? Is a bare PCB available ?
yes, the design is straight from the TI data sheet but the layout is mine.
The last batch I made was years ago and I only have the populated boards for use in repairs. the Paraound was a drop in but the Levinson No35 resquires a clock buffer replacement and the No30.5 requires a different PCB.
If you still have the Gerbers, I would order some (perhaps 10pcs.) new bare PCBs in China and offer it here to other users.
I also could edit the layout to add a clock buffer.
This would cost most certainly not more than 10USD per piece.
I still have a few PCM1704U-J in my drawer. This would be probably the best way to get them used.
I also could edit the layout to add a clock buffer.
This would cost most certainly not more than 10USD per piece.
I still have a few PCM1704U-J in my drawer. This would be probably the best way to get them used.
It would be interesting to know which components fail in the D20400.
What difference occurs while a listening test between the genuine D20400a device and the PCM1704 replacement PCB ?
BTW - this offerer make the same with an old PCM63:
1pc HIFI PCM63 DAC module Replaces UltraAnalog D20400 Dual 2.0 Audio DAC 926319274034 | eBay
And a second question:
What is the main issue with the replica of the original circuit from Ultra Analog (at least according the images in post #38 under
Ultra Analog D20400 datasheet?
a circuit diagram should actually be made) ?
P.S.: I am looking for faulty D20400 modules.
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Which version ? D20400 or D20400a ?
I am looking for the datasheet of the successor of D20400, the D20400a.
Thank you for upload.