Hi everyone,
Im planning to develop my own DAC, but i want to know if is it really worth to
use a combination of DAC with Sample Rate Converter in this case PCM1796 + AK4127VF.
Does enyone has experience in this subject?
Im planning to develop my own DAC, but i want to know if is it really worth to
use a combination of DAC with Sample Rate Converter in this case PCM1796 + AK4127VF.
Does enyone has experience in this subject?
I have also used an asynchronous sample rate converter (ASRC) in a DIY DAC, but not with the chips you mention. In my case the sample rate conversion is done by an SRC4392 and an FPGA module and the DAC consists of E88CC valves, see https://linearaudio.net/sites/linearaudio.net/files/03 Didden LA V13 mvdg.pdf .
If you want to make a DAC that can work with any old S/PDIF, Toslink or AES source, the DAC has to be able to synchronize to the incoming clock. With an ASRC, you can just run the DAC on a good local clock source that need not be tunable and use the ASRC for the synchronization and the suppression of the jitter on the incoming signal. That's why I ended up using an ASRC.
The disadvantage is of course that the ASRC has imperfections of its own, such as passband ripple (which translates into pre-echo when it is a linear phase filter, see the article I linked to) and possibly clipping on intersample overshoots.
I don't see any advantage in ASRC if you can synchronize your source to the local DAC clock.
If you use ASRC, I would advice you to use an output sample rate that has no relation with any of the standard sample rates, so you can't get whistles at sum and difference frequencies of harmonics of the incoming sample rate and DAC sample rate (as explained in more detail in the article).
By the way, the CT7302 has a much smaller passband ripple than the AK4127 and AK4137. The AK4137 has the same ripple spec as the AK4127, but has a wider sample rate range and an optional apodizing filter.
If you want to make a DAC that can work with any old S/PDIF, Toslink or AES source, the DAC has to be able to synchronize to the incoming clock. With an ASRC, you can just run the DAC on a good local clock source that need not be tunable and use the ASRC for the synchronization and the suppression of the jitter on the incoming signal. That's why I ended up using an ASRC.
The disadvantage is of course that the ASRC has imperfections of its own, such as passband ripple (which translates into pre-echo when it is a linear phase filter, see the article I linked to) and possibly clipping on intersample overshoots.
I don't see any advantage in ASRC if you can synchronize your source to the local DAC clock.
If you use ASRC, I would advice you to use an output sample rate that has no relation with any of the standard sample rates, so you can't get whistles at sum and difference frequencies of harmonics of the incoming sample rate and DAC sample rate (as explained in more detail in the article).
By the way, the CT7302 has a much smaller passband ripple than the AK4127 and AK4137. The AK4137 has the same ripple spec as the AK4127, but has a wider sample rate range and an optional apodizing filter.
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Yet, a properly implemented AK4137 sounds incredibly better than CT7302. I tried to get the best possible out of each of them. After trying everything I could think of with CT7302, including consultations with the manufacturer, I gave up on it.
By the way, there is a existing CT7302 thread where such issues are discussed in more detail: CT7302PL
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If you use ASRC, I would advice you to use an output sample rate that has no relation with any of the standard sample rates, so you can't get whistles at sum and difference frequencies of harmonics of the incoming sample rate and DAC sample rate (as explained in more detail in the article).
By the way, the CT7302 has a much smaller passband ripple than the AK4127 and AK4137. The AK4137 has the same ripple spec as the AK4127, but has a wider sample rate range and an optional apodizing filter.[/QUOTE]
Well im planning to connect the ASRC to USB to I2S bridge, is it worth to do such type of connection?
By the way, the CT7302 has a much smaller passband ripple than the AK4127 and AK4137. The AK4137 has the same ripple spec as the AK4127, but has a wider sample rate range and an optional apodizing filter.[/QUOTE]
Well im planning to connect the ASRC to USB to I2S bridge, is it worth to do such type of connection?
No, I don't think so.
There are USB interfaces, like the Amanero or some construction with a Beagle Bone and a reclocker board from ppy, that can provide a nice and clean clock to the DAC or that can work on a clock provided to them. That is, a clean clock going to the DAC is the master clock for everything. I don't see what advantage an ASRC would have then.
There are USB interfaces, like the Amanero or some construction with a Beagle Bone and a reclocker board from ppy, that can provide a nice and clean clock to the DAC or that can work on a clock provided to them. That is, a clean clock going to the DAC is the master clock for everything. I don't see what advantage an ASRC would have then.
See https://puredsd.ru/ and posts 723 and 726 of https://www.diyaudio.com/forums/dig...-linear-audio-volume-13-a-73.html#post6317161 for more information about ppy's reclocker. It's all DSD centred, but apparently it could also be used for PCM.