Hi everyone,
Does anyone has an updated list of NOS DAC ICs that are currently in production and are not sigma-delta?
The ones that I am aware about are:
PCM56U
AD1851RZ
AD1856RZ
AD1866RZ
I can't find PCM56 chips of the K and J version and devices from AD in the J version.
I'm currently testing an AD1866RZ and it sounds much better than most consumer audio equipment sigma-delta DACs. I can't describe, but for me multibit NOS DACs seem to sound more detailed and natural than sigma-delta, specially in the lower and higher frequencies, but this is only my opinion, in fact most newer OS DACs clearly outperform resistor ladder DACs in terms of measured specifications, maybe I have some hearing or psychoacustic problem(s).
Well going back to the NOS chips, which one from this list sounds the best? I'm more inclined to give the PCM56U a try, maybe in current output configuration? What do you think? 🤔
The PCM56 needs a deglitcher? Or is it only required for single chip stereo applications?
Any suggestions?
The PCM56U sounds better than the AD1866?
All the Best,
Danny
Does anyone has an updated list of NOS DAC ICs that are currently in production and are not sigma-delta?
The ones that I am aware about are:
PCM56U
AD1851RZ
AD1856RZ
AD1866RZ
I can't find PCM56 chips of the K and J version and devices from AD in the J version.
I'm currently testing an AD1866RZ and it sounds much better than most consumer audio equipment sigma-delta DACs. I can't describe, but for me multibit NOS DACs seem to sound more detailed and natural than sigma-delta, specially in the lower and higher frequencies, but this is only my opinion, in fact most newer OS DACs clearly outperform resistor ladder DACs in terms of measured specifications, maybe I have some hearing or psychoacustic problem(s).
Well going back to the NOS chips, which one from this list sounds the best? I'm more inclined to give the PCM56U a try, maybe in current output configuration? What do you think? 🤔
The PCM56 needs a deglitcher? Or is it only required for single chip stereo applications?
Any suggestions?
The PCM56U sounds better than the AD1866?
All the Best,
Danny
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There are a number of delta-sigma DACs that can bypass the digital filter. That would make them non-oversampling.
Hi Tam, thank you very much for your reply.
Anyway how sigma-delta DACs can avoid oversampling? Usually they are based on single bit or "few bits" architectures, could you explain me better how they actually do it? How can you go from 1 or let's say 8 bits to 16-32 bits without oversampling?
All the best,
Danny
I did not know that, nevertheless I'm not interested in sigma-delta DACs, I've edited my last post to reflect that.
Anyway how sigma-delta DACs can avoid oversampling? Usually they are based on single bit or "few bits" architectures, could you explain me better how they actually do it? How can you go from 1 or let's say 8 bits to 16-32 bits without oversampling?
All the best,
Danny
They are not really non-oversampling.
A sigma-delta DAC normally contains a digital interpolation filter (or filter chain) and a digital sigma-delta modulator. You can sometimes disable the interpolation filter, that is, replace it with a zero-order hold, which is jargon for just repeating the latest sample. The sigma-delta modulator itself then still runs at a sample rate that is some high multiple of the input sample rate.
Advantages: intersample overshoot issues much reduced, pre-echo and pre-ringing eliminated.
Disadvantages: sin(x)/x roll-off of the zero-order hold, very poor image suppression, can be fixed to some extent with an analogue reconstruction filter.
This is rather similar to a true non-oversampling DAC, except for the ultrasonic quantization noise of a sigma-delta DAC.
A sigma-delta DAC normally contains a digital interpolation filter (or filter chain) and a digital sigma-delta modulator. You can sometimes disable the interpolation filter, that is, replace it with a zero-order hold, which is jargon for just repeating the latest sample. The sigma-delta modulator itself then still runs at a sample rate that is some high multiple of the input sample rate.
Advantages: intersample overshoot issues much reduced, pre-echo and pre-ringing eliminated.
Disadvantages: sin(x)/x roll-off of the zero-order hold, very poor image suppression, can be fixed to some extent with an analogue reconstruction filter.
This is rather similar to a true non-oversampling DAC, except for the ultrasonic quantization noise of a sigma-delta DAC.
Between these chips:
PCM56
AD1851
AD1856
AD1866
which one sounds the best, assuming that all are of the "standard" version (without K or J)?
I believe the PCM56 is now only available in the U version, do you know if the AD1851 or the AD1856 are still being produced in the J versions?
All the best,
Danny
PCM56
AD1851
AD1856
AD1866
which one sounds the best, assuming that all are of the "standard" version (without K or J)?
I believe the PCM56 is now only available in the U version, do you know if the AD1851 or the AD1856 are still being produced in the J versions?
All the best,
Danny
Based on my experience, AD9717 is glitch-free and provided a sound quality comparable to PCM1704 as an alternative. Since it is an RFDAC, it offers 14-bit resolution up to 100MHz. With two DACs on a single chip, two chips would be required to achieve 16-bit resolution. The output is differential, allowing for simple IV conversion using resistors(up to 1V swing).
While there are several RFDAC options available, AD9717 is the only one suitable for audio purposes. Others tend to have inferior SNR in the audio frequency range. When I upgraded to 16-bit with AD9717, it should have reached around 110dB SNR, which is similar to PCM1704. Personally, I couldn't perceive any difference in sound quality.
Regarding glitch-prone options, LTC2642 comes to mind. It is a voltage-output DAC capable of operating up to around 1MHz. Although it exhibits relatively minor glitches among R2R DACs, it seems to affect the sound quality. While I can't definitively attribute this to the cause, there was a noticeable difference in sound quality compared to PCM1704. It had a brighter sound, which may be a matter of preference, but I found it unsuitable for classical music. Therefore, in my opinion, LTC2642 falls short as an alternative for PCM1704.
While there are several RFDAC options available, AD9717 is the only one suitable for audio purposes. Others tend to have inferior SNR in the audio frequency range. When I upgraded to 16-bit with AD9717, it should have reached around 110dB SNR, which is similar to PCM1704. Personally, I couldn't perceive any difference in sound quality.
Regarding glitch-prone options, LTC2642 comes to mind. It is a voltage-output DAC capable of operating up to around 1MHz. Although it exhibits relatively minor glitches among R2R DACs, it seems to affect the sound quality. While I can't definitively attribute this to the cause, there was a noticeable difference in sound quality compared to PCM1704. It had a brighter sound, which may be a matter of preference, but I found it unsuitable for classical music. Therefore, in my opinion, LTC2642 falls short as an alternative for PCM1704.
Thank you very much for your reply xx3stksm.
Both the AD9717 and LTC2642 seem to be interesting options, however, the AD9717 doesn't seem to be compatible with the 16bit right justified audio format neither I2S, that makes configuration more difficult, in addition it has a lot of pins which greatly complicates the soldering task.
The LTC2642 seems to be compatible with the 16bit right justified format, but I can't find a THD specification, so I don't know how it performs in terms of SINAD, also I think the data word is not in two's complement.
I think I'm still up for the other 4 options (PCM56, AD1851, AD1856, AD1866), which one do you think is the best option?
Both the AD9717 and LTC2642 seem to be interesting options, however, the AD9717 doesn't seem to be compatible with the 16bit right justified audio format neither I2S, that makes configuration more difficult, in addition it has a lot of pins which greatly complicates the soldering task.
The LTC2642 seems to be compatible with the 16bit right justified format, but I can't find a THD specification, so I don't know how it performs in terms of SINAD, also I think the data word is not in two's complement.
I think I'm still up for the other 4 options (PCM56, AD1851, AD1856, AD1866), which one do you think is the best option?
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Have you heard a non-oversampled, delta-sigma DAC? The DDDAC, which uses a PCM1794, is very popular in this forum. I think the bad rap for delta-sigma DACs comes from the mediocre interpolation filters that are integrated in many DAC chips. Bypassing the built-in filter lets you substitute a better quality filter or use none at all.
Sorry but I'm not really interested in advanced segment DACs or any other sigma-delta implementation, I've never heard a PCM1794, but I've heard a PCM5101A and I'm not a big fan of the sound that it makes, it seems better than single-bit sigma-deltas but worse than resistor ladder DACs.
Yes, in part, but it also has the sigma-delta section. 🤔
Not really that much different from TI's advanced segment.
Very complicated design and not to my taste I guess.
Not really that much different from TI's advanced segment.
Very complicated design and not to my taste I guess.
Cant it be bypassed? Reason I say is my RME is AKM based and its the most natural sounding DAC I've heard aside from NOS TDA1541A and PCM63.
I don't know how to do it, any suggestions?
The AX4499EX + AK4191 combination can be the world's best sounding DAC but for me it is cost prohibitive, the circuit is also very complex and has a lot of connections.
Which IC from AKM it uses?
These and the PCM1704 or the AD1862 are the ones I am interested in, but unfortunately they are no longer produced.
It seems most Do-It-Yourself-Audio users are unable to do anything for themselves. Why can't you look at the inventories of your favorite chip suppliers or use findchips.com to search every major supplier in the world? And why do the chips have to be in current production? After the production stops, there are still thousands of authentic parts in the distribution channels and EOL suppliers.
How do I know if these parts are not fake? They are no longer produced.
The suppliers that can chip to europe sometimes do not have the high performance versions in stock.
Thank you very much, does it ship to europe?
Edit
I think it's here
https://www.digikey.pt/pt/products/...1862N/12107023?s=N4IgTCBcDaIIIBMCMAOAbBAugXyA
Right?
If so there is one problem, because it only ships in packages of 12, that's too much for me, very expensive, maybe I should join a group buy.
I also have another problem, but this one is regarding implementation, how can I interface the AD1862 with a DIR9001, is it possible?
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@danny92 Almost everything is solved here: https://www.diyaudio.com/community/threads/dac-ad1862-almost-tht-i2s-input-nos-r-2r.354078/
yes, group buy is the best option 🙂
yes, group buy is the best option 🙂
That post is really helpful, but it is also huge, you have made a very nice PCB which allows a lot of possibilities. 😉
Do you have a schematic of the digital circuit required for I2S to the AD1862's format?
How can I start a group buy? I know there is a specific section for that in diyAudio, I can just create a thread there or is it a bit more difficult than that? I also don't know how the shipping is processed.
Do you have any suggestions for I/V and reconstruction filter? I'm looking for a simple solution based on opamps, I really like the sound of LM4562 and NE5532, but I'm not sure if they are good options for those stages.
All the best,
Danny
Do you have a schematic of the digital circuit required for I2S to the AD1862's format?
How can I start a group buy? I know there is a specific section for that in diyAudio, I can just create a thread there or is it a bit more difficult than that? I also don't know how the shipping is processed.
Do you have any suggestions for I/V and reconstruction filter? I'm looking for a simple solution based on opamps, I really like the sound of LM4562 and NE5532, but I'm not sure if they are good options for those stages.
All the best,
Danny