About jitter ... I don't recall any mention of "jitter" per se in any tech paper or even Red Book until about the end of the 1980s. Well into the 4th/5th gen players and early stand-alone D/A processors. And then there was another metric du jour gaining popularity: linearity.
But all this spec craze was years after some decent sounding TDA1540/1 machines -- especially the mod jobs, and Meridian and Misson high-enders -- began convincing the vinyl community that digital was pretty good.
But all this spec craze was years after some decent sounding TDA1540/1 machines -- especially the mod jobs, and Meridian and Misson high-enders -- began convincing the vinyl community that digital was pretty good.
Regarding random jitter, there is jitter that corresponds to close-in phase noise and jitter that corresponds to far-off phase noise. Those early many-bit DACs were far less sensitive to far-off phase noise than some types of sigma-delta DAC.
This is because in ancient primitive DACs (like 13-bit 1540), jitter had little effect, due to their general wretchedness.
Rather because the step sizes were smaller than those of a 1 bit DAC, and there were fewer steps per unit time due to the lower oversampling rates. Nowadays the sensitivity to far-off phase noise is reduced again with FIRDACs and multibit sigma-delta modulators.
The effect of jitter is proportional to the bit depth.
So of course 13-14 bit DACs are less sensitive than 20-24 bit ones.
So of course 13-14 bit DACs are less sensitive than 20-24 bit ones.
How so?
In one sense the depth of a bit in DSD is from 0 to full scale. The analog output is according to the area under the curve. A given switching time error will change the area more in that case as opposed to if the amplitude of the step change were much less. In the latter case the area change under the curve, due to the timing error, for that small step change is relatively small. At least that is a simplistic model.
Since you have experience using the AK3137, does it feature a hardware control mode, or is it software programmable only? I very briefly skimmed through the DS, and spotted mention of I2C, but at 80 pages length, I may have missed whether the device also supports a pin-programmable control mode so that an MCU program doesn't have to be written and loaded to use it.
This statement contains a few misconceptions:
- ASRC dont act like a buffer, nor does it have its special signum - delay.
- Nor does it act like a re-klocker. A re-clocker is a synchronous, meaning same clock in as out, but repairs the timing in the re-clocked signal. No faults > a clock cycle can be repaired or slip or repetition need to occur.
//
AK4137 has hardware control mode (AKM calls it parallel control mode) but power-up reset handling (PDN pin) needs to be provided. This can be implemented with a simple RC delay + schmitt trigger.
Don't see the AK4137 being used that much in consumer electronics or audiophile market.
Use Filter tool here:
http://vasiltech.narod.ru/CD-Player-DAC-Transport.htm
But that same site does show stand-alone ASRCs, like the AD1896, being extensively used, even up to (almost) this day. Example: Mytek DACs.
Use Filter tool here:
http://vasiltech.narod.ru/CD-Player-DAC-Transport.htm
But that same site does show stand-alone ASRCs, like the AD1896, being extensively used, even up to (almost) this day. Example: Mytek DACs.
That's an incomplete database. Benchmark DAC-3 was once one of the very top measuring dacs available, and IIRC, A or A+ rated at Stereophile. Like DAC-2 it used an SRC4392 ASRC/SPDIF Transceiver. DAC-3 also used a Spartan 6 FPGA for external digital signal filtering. Those two devices were a lot of what differentiated the sound of DAC-3 from other dacs using ES9028PRO dac chips. Database misses both of those.
Also IIRC, AK4137 was used in the original Holo Spring dac. Not finding an entry for that either.
Also IIRC, AK4137 was used in the original Holo Spring dac. Not finding an entry for that either.
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Just acquired another Amanero ... this one is supposed to be the better device, as suggested elsewhen in this forum. (Both shown in photos below)
Recent success with the AD1896 asrc ** is prompting another potential experiment. Up-sampling w/o over-sampling.
[** Highly suggest others repeat that experiment -- easy to to do -- and report back.]
I do have two ASRCs ready to go: CS4121 and AD1896. Also have SRC4192 on hand (but that still needs to soldered onto green proto board).
Several DACs in the parts bin ... but many have built-in DFs already. AD1862 might be a good candidate.
Or how about ....
Recent success with the AD1896 asrc ** is prompting another potential experiment. Up-sampling w/o over-sampling.
[** Highly suggest others repeat that experiment -- easy to to do -- and report back.]
I do have two ASRCs ready to go: CS4121 and AD1896. Also have SRC4192 on hand (but that still needs to soldered onto green proto board).
Several DACs in the parts bin ... but many have built-in DFs already. AD1862 might be a good candidate.
Or how about ....
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A follow-up on the ASRC ad1896 experiment that should've been continued in this thread, not the RESET (with overbar) thread.
The high-school math exams I grew up with were prefaced by a note in BOLD: Show Your Work.
Hence, for the "exam" experiment, note:
Amanero feeding I2S plus MCK into the AD1896 w/ music [Not shown, no music on DATA. It is 0.0hz]: .
=========================
AD1896 feeding the TDA1305 dac w/, and w/o music [note that DATA line playing no music, has "background" 132.xx Khz signal --- dither??? Also note that up-sampling is an integer 2x, which is ideal ].
Further comparing sonics of crude up-sampled bread and protoboard set up against my much-modded Chinese dual (parallel) tda1305 kit, are very positive. But, to be fair, the Chinese kit is battling its internal inferior USB topology, as well as no ASRC.
The high-school math exams I grew up with were prefaced by a note in BOLD: Show Your Work.
Hence, for the "exam" experiment, note:
Amanero feeding I2S plus MCK into the AD1896 w/ music [Not shown, no music on DATA. It is 0.0hz]: .
=========================
AD1896 feeding the TDA1305 dac w/, and w/o music [note that DATA line playing no music, has "background" 132.xx Khz signal --- dither??? Also note that up-sampling is an integer 2x, which is ideal ].
Further comparing sonics of crude up-sampled bread and protoboard set up against my much-modded Chinese dual (parallel) tda1305 kit, are very positive. But, to be fair, the Chinese kit is battling its internal inferior USB topology, as well as no ASRC.
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Do you mean using an ASRC with the exact same input and output sample rates? The only advantage I could think of is that the AD1896 can properly round > 20 bit signals to the 20 bit word length of your DAC.
Not to be "mean" (= facetious), but I don't know what I mean 😉
That is, I don't know why the ASRC improves sonics? I definitely heard improvement when I added the AD1896 into the 1305 setup -- compared to no SRC.
Yes, as can be noted in the photos, the AD1896 will 2x "oversample". But it might be interesting to use the ASRC with, say, a TDA1543 or 1545 or 1541.
I suppose I should do some objective tests. But one can only go so far w/o, say, this: https://www.ap.com/analyzers-accessories/apx555/
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According to TDA1305 datasheet tables 3 & 5 all filter characteristics are worse with double speed.
Yeah, I saw that and the note on pg. 8.
Weirdly, table 5 (double speed) does not provide a "SAMPLE FREQUENCY" column as Table 3 does.
I suppose it's not surprising that the faster the internal circuits are asked to perform (2x vs 1x), the more demands there will be on power supply and regulation. So more hash in line. Delta-sigmas run so fast that they have to noise-shape their way out of that mess. The 1305 does do a little noise-shaping per its "hybrid" design.
Btw: from p. 2 of datasheet:
"The TDA1305T is a dual CMOS DAC with up-sampling filter and noise shaper."
Hmmm ... in any case, ... Naim liked it, in their Golden Years 😉