This is sad..
Another interesting thing is why chip manufacturers don't see the problem, and resurrect the manufacturing old chips.
I can understand the logic behind integrating more components/functionalities into the chip, for small mobile devices, that maybe don't need the best sound quality. But for people at home, who want a better sound, and the manufacturer of the audio product/system has no constraint in space, the older chips, that do not include the additional features built-in, would be better.
Don't chip manufacturers see this? They can revive the production of their older chips.. Not just for the DIY community (which is obviously small, for affecting production decisions), but for audio product manufacturers themselves, who wish to get the better sound quality DAC chips.
Another interesting thing is why chip manufacturers don't see the problem, and resurrect the manufacturing old chips.
I can understand the logic behind integrating more components/functionalities into the chip, for small mobile devices, that maybe don't need the best sound quality. But for people at home, who want a better sound, and the manufacturer of the audio product/system has no constraint in space, the older chips, that do not include the additional features built-in, would be better.
Don't chip manufacturers see this? They can revive the production of their older chips.. Not just for the DIY community (which is obviously small, for affecting production decisions), but for audio product manufacturers themselves, who wish to get the better sound quality DAC chips.
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Uh, maybe I can take a try at explaining the situation with S-D chips like ESS. Like other kinds of things, they are designed at a price point and with included features likely to get the chip selected for the most end-use product designs. In addition, it happens that S-D are very revealing of everything, including all the little low -level details in music, but also of their own limitations and the limitations of the circuitry around them. Those things just go along with more ENOB, low noise, and fairly low distortion. I say 'fairly' low distortion because even at -120dB THD it can be audible if noise and or low ENOB do not obscure it. (This assumes a power amp and speakers capable of not adding their own masking of small details.)
The internal features of the S-D chips are good enough for the price points most manufactures are aiming for in the market. We are at a point in time where dacs chips are very revealing, but to be revealing of the details of the music and nothing else is still complicated and expensive.
One of things the chips are revealing of is jitter, which even at very low levels produces audible problems. The internal ASRC and the internal PCM interpolation filters in ESS chips could be better in that their shortcomings are revealed just like everything else is. No doubt they could be made better by ESS, but already the chips are a costly part of many dac designs. How much are dac manufacturers willing to pay for dac chips to be used in very price-sensitive markets?
The reason DSD sounds better likely simply has to do with the fact that the digital filtering needed inside S-D dac chips is much more simple for DSD than for PCM. With good enough PCM interpolation filtering it could sound just as good as DSD, IMHO.
So, in the meantime where we are right now we have to make some choices about what we want and what we are willing to pay for. We can go with older and less revealing dac chips and hear less of what was actually recorded, or we can have the extra detail in pretty accurate form (still not perfect) if we are willing to go to enough cost and complexity to get it. If we want to use 'chip' dacs to do it, then we have to deal with the kind of chips market economics can justifiably produce, and with the associated cost and complexity.
Probably, we can mostly blame human hearing for the issues. It is hard to get all forms of distortion and noise not just to -120dB, but well below -120dB. We might be talking ideally, maybe -130dB or -140dB (for distortion) before we get defects down to the level they inaudible to any human, and maybe not even then. We simply don't know because it has never been studied using the kind of testing systems we could make today if we make them the best we know how to do.
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From standard china sources (mostly used components, not tested, go with parts in DIP, avoid the PCM1704 from china sources) ...,
UTsource (I dont know if they are genuine, I have not asked for protocol) ... a lot of different chips (incl. TDA1387), I bought from them AD1865, AD1862, PCM1702, all are working fine
Rochester Electronics (genuine parts, I asked for the protocol and they sent it to me), a lot of genuine chips, like:
AD1862, AD1865,
PCM1704
You are not alone ... a lot of audio engineers run the marathon for "the best overkill in the delta-sigma world"
You can read about a ready made AD1865 DAC here:
AliExpress AD1865 R2R DAC
Unfortunately it works in NOS mode so everything above 5kHz won't look good...
I would go with AD1862, AD1865 or PCM63
AliExpress AD1865 R2R DAC
Unfortunately it works in NOS mode so everything above 5kHz won't look good...
I would go with AD1862, AD1865 or PCM63
Higher frequencies can be cleaned up somewhat with a CLC filter between DAC and I/V opamp.
Besides, I asked Analog Devices for the genuity of their obsolete products and Analog Devices responded to me:
"Please note that Rochester Electronics is the only authorized sources of Analog Devices' products that have previously been discontinued or have become obsolete."
Hope that helped
More interesting is why you don't see the problem with you seeing a problem here.
How much do you think it will cost to reconstitute, more likely rebuild from scratch, the semiconductor fabs on which these chips were originally built ? A modern process simply won't do. It wouldn't be authentic.
Anyway you can buy a R2R DAC from other source. They are cheaper but note, most of them are products from electronic scrap. I recommend only DIP packages (because they did not need to be removed by a heatgun). I strictly do not recommend PCM1704 from ebay and other china sources (SMD chips degraded by heat during recycling).
Will be very interesting to hear your impression after it's built..
Please write..
BTW, will your board be powered from USB, or need an external power supply?
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