Hello Everyone,
I believe I have searched forums long enough to re-start this topic (everything I found is dead and at least 3 years old)...
I am on my second AES-21 in my Classe DAC-1 and it's starting to fail again. I know many others with Parasound DAC 2000s or other Ultra Analog DACs have the same pain with their AES-21s (or 20s).
So it's about time I (or maybe someone already has?) made a plug-and-play replacement with new parts, maybe a quality crystal re-clocker, that for whatever reason doesn't die so easily. I'm thinking CS8416 with tolerant filter -> some nice crystal-based PLL with tight filter. This will go (at least in my Classe) straight out to the PMD-100 HDCD filter so I should have some room to work with on the module for good power supply, decap, etc.
In summary the idea here is to put a good RELIABLE receiver and 21-st century clock (whatever will fit!) in these great old DACs with minimal fuss.
If anyone knows anything or has any recommendations it would be appreciated. Or if you've already done the same thing a starting point would be a time-saver. I'll make a PCB that matches the AES-21 pinout so if anyone is REALLY interested let me know if you'd like a finished one once I get around to parts (several months from now...)
Thanks in advance everyone
I believe I have searched forums long enough to re-start this topic (everything I found is dead and at least 3 years old)...
I am on my second AES-21 in my Classe DAC-1 and it's starting to fail again. I know many others with Parasound DAC 2000s or other Ultra Analog DACs have the same pain with their AES-21s (or 20s).
So it's about time I (or maybe someone already has?) made a plug-and-play replacement with new parts, maybe a quality crystal re-clocker, that for whatever reason doesn't die so easily. I'm thinking CS8416 with tolerant filter -> some nice crystal-based PLL with tight filter. This will go (at least in my Classe) straight out to the PMD-100 HDCD filter so I should have some room to work with on the module for good power supply, decap, etc.
In summary the idea here is to put a good RELIABLE receiver and 21-st century clock (whatever will fit!) in these great old DACs with minimal fuss.
If anyone knows anything or has any recommendations it would be appreciated. Or if you've already done the same thing a starting point would be a time-saver. I'll make a PCB that matches the AES-21 pinout so if anyone is REALLY interested let me know if you'd like a finished one once I get around to parts (several months from now...)
Thanks in advance everyone
Hi Korrah,
I have experienced two types of failures, one of which a friend also with an AES-21 shares.
1) My DAC (classe DAC 1) worked perfectly for years until finally zero lock could be achieved on anything. incoming frequency showed 32 kHz (lowest f display on front panel) and lock failure light came on, no sound, dead. I swapped out the AES-21 and it worked perfectly again on power-up.
2) My second AES-21 is having seemingly random pauses in sound, as if dropping samples. Sometimes it's like a CD skipping, sometimes I get 40 minutes of perfect before failure, sometimes just 1 minute between a slight hiccup. This behavior a friend of mine also experiences although much less often and he has a different DAC than mine (parasound 2000).
Both of us have clock-upgraded CD players so our incoming SPDIF streams are much cleaner than normal - the cirrus part in the AES 21 (i think it was an 8412 they used) might be failing or maybe the XO they use to re-clock afterward is (pretty sure from pictures I've found that there's a second PLL in the AES-21 that re-clocks).
I will have a schematic for the new AES-21 module very soon. I've explored a few different options and will upload once I finish with the details.
I have experienced two types of failures, one of which a friend also with an AES-21 shares.
1) My DAC (classe DAC 1) worked perfectly for years until finally zero lock could be achieved on anything. incoming frequency showed 32 kHz (lowest f display on front panel) and lock failure light came on, no sound, dead. I swapped out the AES-21 and it worked perfectly again on power-up.
2) My second AES-21 is having seemingly random pauses in sound, as if dropping samples. Sometimes it's like a CD skipping, sometimes I get 40 minutes of perfect before failure, sometimes just 1 minute between a slight hiccup. This behavior a friend of mine also experiences although much less often and he has a different DAC than mine (parasound 2000).
Both of us have clock-upgraded CD players so our incoming SPDIF streams are much cleaner than normal - the cirrus part in the AES 21 (i think it was an 8412 they used) might be failing or maybe the XO they use to re-clock afterward is (pretty sure from pictures I've found that there's a second PLL in the AES-21 that re-clocks).
I will have a schematic for the new AES-21 module very soon. I've explored a few different options and will upload once I finish with the details.
It absolutely can be done, but your Sonic Fronteirs' digital filter chip, listed as the awful PMD100 hdcd chip, can't handle anything above 20/48. But, if it were my dac, I would buy a conversion module from ASE audiotuning to replace the PMD100 with a non-hdcd DF1704 or SM5847, either of which will make your dac sound DRAMATICALLY better. You will still be limited by the UA dac chips to 20bit(don't know how high sampling rate they can handle), but it should nonetheless benefit from the above.
Thank you. That is very interesting, as I have recently tracked down intermittent dropouts in my Adcom GDA-700 to the AES-21 module.
Has anyone here tried out one of these repalcement modules?
Does anyone know if they are a straight pin-for-pin functional replacement?
I had been experiencing intermittent failures of the Ultra Analog converter in my 20 year old Adcom GDA-700 DAC.
I took the plunge (it's not cheap) and ordered one of the replacement modules from Parts Connexion.
The new module is a direct drop-in replacement. It has been working flawlessly for over a week now.
I have attached "before" and "after" pictures.
I took the plunge (it's not cheap) and ordered one of the replacement modules from Parts Connexion.
The new module is a direct drop-in replacement. It has been working flawlessly for over a week now.
I have attached "before" and "after" pictures.
I certainly couldn't tell the difference with the replacement. I listen failrly critically every night with headphones which would show up any differences. By the way, my DAC has not missed a beat since I installed the replacement 4 months ago. I had previously tried re-flowing the solder, but that did not fix the problems. The AES-21 is responsible for separating the data from the clock as it is received combined. It also works to reducing the clock jitter to very low levels. While this may have an effect upon audio quality, it is not in the "analogue signal path" as such.
URL is dead: go to
https://web.archive.org/web/20140625081840/http://www.partsconnexion.com/parts_sonic_frontiers.html
check out post #15 under
https://www.diyaudio.com/community/...-ultra-analog-dac-d20400.377627/#post-7145197
and ask this supplier:
https://www.ebay.com/itm/115121794212
Hello,
Sorry for the long period of silence, but I have had some sad problems with my father: he passed away before Christmas, and soon after the mother of my wife also passed away (3 days before Christmas...).
I am back (with a low availability) and here are the news regarding the AES-21 replacement socket.
I have worked during the 2nd half of 2023 with a major parts distributor, to whom I have sent the replacement module that I have designed. They commit to debug it, they started to work on it seriously, but I have got no news since weeks: I even do not know if they have abandoned the project (or if they plan to sell my socket by by-passing me ?....
).
This socket is designed to be a "plug & play" module: same size and same pinout than the original Ultra-Analog AES-21 module.
I have spent a lot of time to design it, and the last news I got is that it stays permanently in the "lock" position, which is obviously a problem. Except this, I am confident that the socket should be very close from a working module...
I have all the tools and expertise for this socket (PCB design, SMD soldering, etc...) but I have nothing to test it in real conditions, and therefore I don't have the necessary equipment to find the remaining issue
Consequently, it seems that the only way to get a working module, is to find somebody that could conduct the tests and identify the remaining issue (receiver permanently locked).
If somebody has the equipment and knowledge to conduct these tests, I will source the parts needed to solder a new prototype and exchange with him.
Thanks for your replies,
Sorry for the long period of silence, but I have had some sad problems with my father: he passed away before Christmas, and soon after the mother of my wife also passed away (3 days before Christmas...).
I am back (with a low availability) and here are the news regarding the AES-21 replacement socket.
I have worked during the 2nd half of 2023 with a major parts distributor, to whom I have sent the replacement module that I have designed. They commit to debug it, they started to work on it seriously, but I have got no news since weeks: I even do not know if they have abandoned the project (or if they plan to sell my socket by by-passing me ?....
).This socket is designed to be a "plug & play" module: same size and same pinout than the original Ultra-Analog AES-21 module.
I have spent a lot of time to design it, and the last news I got is that it stays permanently in the "lock" position, which is obviously a problem. Except this, I am confident that the socket should be very close from a working module...
I have all the tools and expertise for this socket (PCB design, SMD soldering, etc...) but I have nothing to test it in real conditions, and therefore I don't have the necessary equipment to find the remaining issue
Consequently, it seems that the only way to get a working module, is to find somebody that could conduct the tests and identify the remaining issue (receiver permanently locked).
If somebody has the equipment and knowledge to conduct these tests, I will source the parts needed to solder a new prototype and exchange with him.
Thanks for your replies,