Thank you very much Mr. Wu for providing the module. Very regret. The module is damaged. Mr. Wu kept it for 13 years, and now he has given it to me. I think I can fix him. But I'm very sorry, what he damaged was the main control chip OKI M72H035. I cannot purchase him from all over the world. I searched the whole world. No one is selling. So I made an IIS signal generator. I want to test the generation of the problem. After careful testing. Discovered that the right channel BIT17 has been at a high level for a long time. Cannot switch. I think M72H035 is completely irreparable. I want to restore the entire chip. But it's impossible. Without this main control chip, all operations are equal to 0. I used my vacation days to simulate the entire timing sequence using gate circuits. I think I can resurrect him. However, the original design had some shortcomings. Because the R-2R part uses AD7541 plus two very difficult to obtain non-standard resistance resistors. I think I can improve it. I replaced him with a more suitable chip AD7538. Now D20400 has become a true 20 bit module. It's no longer fake 20 digits. I want to share him with all friends who pursue D20400. You can purchase it now, but EU friends need to provide an IOSS number. He is composed of IM and 10 digits. Sent from Guangzhou, China. Europe needs 10 days. If you would like to obtain any information, please email: 410746700@qq.com
You can directly replace the damaged module. Because everything is completely identical.
The owners of this vintage digital devices (according vasiltech list) now will be very happy - so I think:
1) CD-player:
CLASSE AUDIO with CDM12.1, KRELL KPS 25s with JVC EXU-901A and OPTIMA-4,
SONIC FRONTIERS SFCD-1 with CDM12.4
2) DA-converter:
APRIL MUSIC Reference, AVANTGARDE B1, LAKE PEOPLE DAC F20, LANGEVIN 20 BIT DAC
STAX DAC-X1T , THRESHOLD DAC 2 , VTL 20-BIT DAC , VTL STRAIGHT-LINE
AUDIO RESEARCH DAC1-20 , AUDIO RESEARCH DAC2, AUDIO SYNTHESIS DA-X
AUDIO SYNTHESIS DAX-2 , AUDIO SYNTHESIS DAX-Decade/DAX DSM
CLASSE AUDIO DAC-1 , COUNTERPOINT DA-10E-UA , Kinergetics Research KCD-55 Ultra
MANLEY A TO D CONVERTER , MANLEY JUNIOR/Reference/Wave, MARK LEVINSON No 30/30.5
METAXAS MASDAC, PARASOUND D/AC-2000
PS AUDIO REFERENCE LINK II, PS AUDIO ULTRALINK/ULTRALINK TWO, RESOLUTION AUDIO Quantum
SONIC FRONTIERS SFD-1/SFD-2 MKI+II, SPECTRAL SDR-2000
1) CD-player:
CLASSE AUDIO with CDM12.1, KRELL KPS 25s with JVC EXU-901A and OPTIMA-4,
SONIC FRONTIERS SFCD-1 with CDM12.4
2) DA-converter:
APRIL MUSIC Reference, AVANTGARDE B1, LAKE PEOPLE DAC F20, LANGEVIN 20 BIT DAC
STAX DAC-X1T , THRESHOLD DAC 2 , VTL 20-BIT DAC , VTL STRAIGHT-LINE
AUDIO RESEARCH DAC1-20 , AUDIO RESEARCH DAC2, AUDIO SYNTHESIS DA-X
AUDIO SYNTHESIS DAX-2 , AUDIO SYNTHESIS DAX-Decade/DAX DSM
CLASSE AUDIO DAC-1 , COUNTERPOINT DA-10E-UA , Kinergetics Research KCD-55 Ultra
MANLEY A TO D CONVERTER , MANLEY JUNIOR/Reference/Wave, MARK LEVINSON No 30/30.5
METAXAS MASDAC, PARASOUND D/AC-2000
PS AUDIO REFERENCE LINK II, PS AUDIO ULTRALINK/ULTRALINK TWO, RESOLUTION AUDIO Quantum
SONIC FRONTIERS SFD-1/SFD-2 MKI+II, SPECTRAL SDR-2000
We see an impressive list of modules for sale but in the end no one is interested! The seller should do things differently to convince people
Thanks. Truly good cuisine only requires simple cooking, and truly good products only require a three or two word introduction. Because it exceeds the quality of the original module and the sound is also more ideal. It supports one-year replacement, excluding shipping costs.
I think most people are afraid to try because they are afraid that the structure will completely detach from D20400. Please rest assured that it is now completely identical to D20400. I will open up the upper level design to dispel your concerns. The only known module that can truly replace D20400 is this one. Because the sound is exactly the same as the D20400. I designed two versions. One is a genuine 18BIT, D18400PLUS, whose R-2R part is the same as D20400 or D20400A. The other is the genuine 20BIT, D20400PLUS, whose R-2R part surpasses D20400 and 20400A. There is a saying in China, will you become the first person to eat crabs. Many people in China became the first to eat crabs. But the only person who has ever eaten crab in the West is a friend from Krakow, Poland.
How can one conclude whether this really corresponds to reality?
in the 1990s there was a wide range of DAC ICs (TDA1541, TDA1574, PCM63/1702/1704 AD1862 and much more) and each DAC had their own sonic character and since many user's want to have their known sound character from early days, I don't think this idea is bad.
P.S.: I am wondering whether the same error always occurs in the original potted modules D20400/D20400a from Ultra Analog as the cause of failure (i.e. in a specific and always the same component), or whether there are always different causes that lead to the failures.
Any experiences ?
Let me answer everyone's questions one by one. First of all, thank you to the friend who sent the private message. What everyone is most concerned about is whether AES21 is still in production. I will provide a unified response here, that's correct. We are currently designing AES21. But I need some time, I am currently testing. An AES version has been developed, which includes coaxial and Bluetooth signals. CSR8675 Bluetooth reception. Unfortunately, the pins are not compatible with AES21, but soon you will see a new version of AES21 that will be fully compatible with AES21. Even better performance. I will showcase the current AES balanced version. He has integrated PLL circuits internally. Therefore, CSR8675 can be connected to digital filters such as SM5803 or PMD100.
Thank you, Tiefbassebert. Before answering your question, I would like to introduce myself to everyone. I have made all the DAC chips. Attention: It is all. It includes module DAC and chip DAC. Thanks to these experiences, we were able to successfully complete the production of D20400. Otherwise, it cannot be completed. Let me talk about some drawbacks of the D20400 original version. I think anyone who likes D20400 knows its strengths, but not its weaknesses. Among all the modules I have dissected. Found some traces of customization. Each factory will customize modules according to their own sound requirements, and of course, I can also help you replace internal operational amplifiers according to your needs. The customized module mainly involves replacing different operational amplifiers to change the sound quality. At present, all the modules I produce use AD712. If you like other operational amplifiers, please let me know. I will replace it according to your request. But it takes time. The shortcomings of the original D20400 vary depending on the customization. For example, a portion of D20400 uses TL431 as a benchmark, which I don't want to elaborate on, as it differs from LT1021 in terms of heaven and earth. For example, the R-2R reference inside D20400A is lowered to+5V, resulting in an output resistance of several hundred ohms, which reduces the dynamic information of the music. For example, the R-2R part uses AD7541+2 resistors, which will generate noise outside the chip. There are still many things that I cannot explain clearly due to my poor English. But all of them are just minor issues. Otherwise, D20400 cannot become popular worldwide. People all over the world like him. But I tried my best to improve it during production. Make it stronger. His malfunction was caused by poor soldering and damage to the CPLD. Now I use pure manual welding. Each of your modules is handmade. He will be more durable.
Congratulations: I have registered for eBay and successfully released the product. This is a big step towards success.
https://www.ebay.com/itm/196760377719
https://www.ebay.com/itm/196760377719
Hello,
the card works, we have the ultra analog sound, we find all the magic of the original chip.with very careful listening, there is a very slight difference, but this is a matter of detail.we continue the tests.
the next tests will be on a counterpoint da10.
the card works, we have the ultra analog sound, we find all the magic of the original chip.with very careful listening, there is a very slight difference, but this is a matter of detail.we continue the tests.
the next tests will be on a counterpoint da10.