Some interesting discussion about AK4137 and another ASRC that can upsample and convert to DSD512 (although not very well when I tried it). If interested in some details about getting the best from AK4137 maybe worth a look: https://www.diyaudio.com/forums/digital-line-level/357501-ct7302pl-3.html#post6288707
Hi kimschips,
I'm still doing experiments with AK4499 eval board.
Having to learn Circuit Studio in order to make a PCB for some experiments I want to run. It hasn't been a whole lot of fun learning the program because documentation is very limited. Takes a lot of time to get used to its way of working (and to get used to working around its bugs). At least when I'm done with the first board, I will probably be inclined to make more boards for various things in the future.
In terms of remaining work to do before I have a complete dac design that I like the sound of, there is a quite a bit left to go. The Jung regulators for Vref on the eval board are pretty good, but not optimal. I could try to optimize them, which is likely possible, or mabe try some other topologies (already tried some I didn't like).
Also, the eval board only has passively filtered differential analog outputs taken from the I/V opamps. I need to decide on more filtering, output buffering, and SE outputs. Opamps are the easiest way to do the output stage stuff, but think I might be able to get sound I like more using discrete circuitry. Only way to find out is try it and see. Takes a lot time.
EDIT: Other thing I have in mind is to try AK4498 eval board when it comes out. We are all hoping AK4498 will sound even better than AK4499. If so, attention will probably switch to the new chipset.
I'm still doing experiments with AK4499 eval board.
Having to learn Circuit Studio in order to make a PCB for some experiments I want to run. It hasn't been a whole lot of fun learning the program because documentation is very limited. Takes a lot of time to get used to its way of working (and to get used to working around its bugs). At least when I'm done with the first board, I will probably be inclined to make more boards for various things in the future.
In terms of remaining work to do before I have a complete dac design that I like the sound of, there is a quite a bit left to go. The Jung regulators for Vref on the eval board are pretty good, but not optimal. I could try to optimize them, which is likely possible, or mabe try some other topologies (already tried some I didn't like).
Also, the eval board only has passively filtered differential analog outputs taken from the I/V opamps. I need to decide on more filtering, output buffering, and SE outputs. Opamps are the easiest way to do the output stage stuff, but think I might be able to get sound I like more using discrete circuitry. Only way to find out is try it and see. Takes a lot time.
EDIT: Other thing I have in mind is to try AK4498 eval board when it comes out. We are all hoping AK4498 will sound even better than AK4499. If so, attention will probably switch to the new chipset.
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Mark what about this circuit from post 70 could this be used as low cost still high quality replacement for your fine avcc circuit with ltc6655?
OPA based Ultra Low noise VREF for DAC
OPA based Ultra Low noise VREF for DAC
I haven't tried babolcs' proposed AVCC supply, so don't know how it would sound. One could build it and find out. You might want to check your babolcs build with a scope for stability such as when you power it on, and or if you quickly switch in and out a resistor test load to give it a little kick. If it looks to be operating properly and it sounds good to you that's a lot of what matters for a diy project.
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Hi First post,
I wanted a quick opinion on how effective DPLL may be for reducing jitter. I am using a SMSL M500 DAC using a ESS9038PRO D/A chip which per the schematics has a DPLL layer over ASRC. I use USB connection to signal the DAC (which I am guessing is Asynchronous, not sure though - not an EE here, just an enthusiast!) along with my Chromecast Audio Toslink and wanted to see if my DAC is cleaning out the jitter or should i be using a reclocker for the USB and Toslink connections (say those by IFI).
So the questions are:
1) Is my DAC's chip doing jitter elimination inside already or is there another component that is required within the DAC board to support this?
2) If yes, is this jitter elimination done for both USB and Toslink or only for Toslink?
DAC Listing Link: S.M.S.L Audio Official -双木三林官网
D/A Chip schematics showing DPLL:
I wanted a quick opinion on how effective DPLL may be for reducing jitter. I am using a SMSL M500 DAC using a ESS9038PRO D/A chip which per the schematics has a DPLL layer over ASRC. I use USB connection to signal the DAC (which I am guessing is Asynchronous, not sure though - not an EE here, just an enthusiast!) along with my Chromecast Audio Toslink and wanted to see if my DAC is cleaning out the jitter or should i be using a reclocker for the USB and Toslink connections (say those by IFI).
So the questions are:
1) Is my DAC's chip doing jitter elimination inside already or is there another component that is required within the DAC board to support this?
2) If yes, is this jitter elimination done for both USB and Toslink or only for Toslink?
DAC Listing Link: S.M.S.L Audio Official -双木三林官网
D/A Chip schematics showing DPLL:
An externally hosted image should be here but it was not working when we last tested it.
Hi shoaibexpert,
First, the schematic you posted cannot be seen from here, but you aren't allowed to post ESS documents if that's what it was. If it was a schematic of your dac box PCB then you could attach it to your post as a file in Advanced Mode posting. That always works, embedded pictures don't always.
Regarding your questions, ESS Sabre dacs have an internal ASRC, one of the properties of which is that it attenuates jitter (doesn't completely eliminate it).
The dac is configured internally by way of some I2C bus registers controlled by the MCU in your dac box. The MCU usually is programmed to leave the ASRC at its default settings which means its on all the time, and for all inputs. The MCU could change the settings for, say, TOSLINK, but most don't seem to be programmed that way.
The bad news about the internal ASRC is that at its default settings it tends to damage sound quality. Lowering DPLL bandwidth in the I2C registers as ESS recommends helps improve the sound, but few dac manufacturers change it. There is a trade off involved in setting DPLL bandwidth which is that lower settings may not be stable if the input source is too jittery, so there is risk in setting it too low. Unfortunately, TOSLINK tends to be pretty jittery.
To tell if the dac is synchronous or asynchronous, the former requires two dac clocks, the latter only one. Look for clock modules near the dac chip, which is where they typically are located.
By the way, in fully synchronous mode the ASRC is disabled which may give the best sound of all, that or async with the very lowest DPLL bandwidth setting.
First, the schematic you posted cannot be seen from here, but you aren't allowed to post ESS documents if that's what it was. If it was a schematic of your dac box PCB then you could attach it to your post as a file in Advanced Mode posting. That always works, embedded pictures don't always.
Regarding your questions, ESS Sabre dacs have an internal ASRC, one of the properties of which is that it attenuates jitter (doesn't completely eliminate it).
The dac is configured internally by way of some I2C bus registers controlled by the MCU in your dac box. The MCU usually is programmed to leave the ASRC at its default settings which means its on all the time, and for all inputs. The MCU could change the settings for, say, TOSLINK, but most don't seem to be programmed that way.
The bad news about the internal ASRC is that at its default settings it tends to damage sound quality. Lowering DPLL bandwidth in the I2C registers as ESS recommends helps improve the sound, but few dac manufacturers change it. There is a trade off involved in setting DPLL bandwidth which is that lower settings may not be stable if the input source is too jittery, so there is risk in setting it too low. Unfortunately, TOSLINK tends to be pretty jittery.
To tell if the dac is synchronous or asynchronous, the former requires two dac clocks, the latter only one. Look for clock modules near the dac chip, which is where they typically are located.
By the way, in fully synchronous mode the ASRC is disabled which may give the best sound of all, that or async with the very lowest DPLL bandwidth setting.
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Hi @markw4
Thanks for the response. The DAC pic I shared is available publicly on ESS website. It shows a section of the DAC chip that has ASRC and DPLL in one box. As far as I can tell there are no out of the D/A chip on board chips like Accusilicon oscillators etc on my board to help with jitter. So should I assume that my ESS 9038Pro based DAC has inferior Jitter rejection capabilities and look for maybe external before the DAC reclockers?
I know my DAC is asynchronous in USB mode at least...must be the same for Toslink. Would you also agree that the USB asynchronous mode is also prone to jitter and that lowering the DPLL bandwidth to lowest in sync value will help? Would you recommend a USB purifier or reclocker in this case?
Also, after reading your comments I'm wondering if a Toslink reclocker like the IFI Ipurifier be a good idea to use with say Chromecast Audio optical to the DAC?
Many thanks
Thanks for the response. The DAC pic I shared is available publicly on ESS website. It shows a section of the DAC chip that has ASRC and DPLL in one box. As far as I can tell there are no out of the D/A chip on board chips like Accusilicon oscillators etc on my board to help with jitter. So should I assume that my ESS 9038Pro based DAC has inferior Jitter rejection capabilities and look for maybe external before the DAC reclockers?
I know my DAC is asynchronous in USB mode at least...must be the same for Toslink. Would you also agree that the USB asynchronous mode is also prone to jitter and that lowering the DPLL bandwidth to lowest in sync value will help? Would you recommend a USB purifier or reclocker in this case?
Also, after reading your comments I'm wondering if a Toslink reclocker like the IFI Ipurifier be a good idea to use with say Chromecast Audio optical to the DAC?
Many thanks
I found a pic of your dac board online (attached below). The box outlined in red is the clock, and the components around it look to be its local power supply.
From that we know you dac is asynchronous. TOSLINK and USB are both run through the internal ASRC.
From that we know you dac is asynchronous. TOSLINK and USB are both run through the internal ASRC.
Attachments
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Thanks. That's very helpful. I really appreciate you digging up my DAC board.
That just leaves the matter of whether a DAC in this configuration and with this DAC Chip will benefit from external reclockers...for both USB and Toslink? FWIW, the DAC is giving me an option to select DPLL between a range of 1 to 14 with 7 set as default.
I read on ASR that most DACs, due to their ASRC +DPLL features eliminates jitter to almost nothing and that there is not need for reclockers in modern times and tech. Any thoughts on this is also welcome.
Cheers
That just leaves the matter of whether a DAC in this configuration and with this DAC Chip will benefit from external reclockers...for both USB and Toslink? FWIW, the DAC is giving me an option to select DPLL between a range of 1 to 14 with 7 set as default.
I read on ASR that most DACs, due to their ASRC +DPLL features eliminates jitter to almost nothing and that there is not need for reclockers in modern times and tech. Any thoughts on this is also welcome.
Cheers
I don't see any practical use for a reclocker.
Regarding DPLL, try setting it as low as you can before the dac playback becomes unstable (depends on incoming jitter level). You may be able to set it lower with USB than with TOSLINK. People tend to report that lowering the DPLL setting improves sound quality quite a bit. You can try it and see what you think.
Also, you may find that the dac sounds better if you can send it DSD256 or DSD512. Presumably, the dac has ASIO drivers for Windows?
There is some software that can upsample and convert CDs to play in DSD format which is very popular with some dac users due to reportedly significantly improved sound quality.
If you don't know how to configure Windows to leave your audio unmangled, there is some advice at https://www.diyaudio.com/forums/dig...z-music-files-cd-standard-11.html#post5993897 ...and more information and advice in the link embedded in the first post. In addition, best to leave Windows volume controls set at full maximum and then use the volume control in your ASIO playback app do any adjusting to want to make (usually no more that a few dB below maximum - whatever gives best sound quality), any further volume control should then be done at the dac.
Regarding DPLL, try setting it as low as you can before the dac playback becomes unstable (depends on incoming jitter level). You may be able to set it lower with USB than with TOSLINK. People tend to report that lowering the DPLL setting improves sound quality quite a bit. You can try it and see what you think.
Also, you may find that the dac sounds better if you can send it DSD256 or DSD512. Presumably, the dac has ASIO drivers for Windows?
There is some software that can upsample and convert CDs to play in DSD format which is very popular with some dac users due to reportedly significantly improved sound quality.
If you don't know how to configure Windows to leave your audio unmangled, there is some advice at https://www.diyaudio.com/forums/dig...z-music-files-cd-standard-11.html#post5993897 ...and more information and advice in the link embedded in the first post. In addition, best to leave Windows volume controls set at full maximum and then use the volume control in your ASIO playback app do any adjusting to want to make (usually no more that a few dB below maximum - whatever gives best sound quality), any further volume control should then be done at the dac.
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Wow. Many thanks for a straight and informative answer. I've come from work and have set my DAC DPLL to minimum and so far both Chromecast Audio Toslink as well as the USB seem to be in sync and I don't experience any drop outs...can't comment on if the SQ has improved as all may experience may be placebo.
The popular SW you mentioned has upsampling via ASIO but due to GUI limitations and lack of Parametric EQ, I am trying to upsample to 352K all my content within windows own sound settings for the DAC.
Anyways, your opinion and guidance is really appreciated. Thanks agian
The popular SW you mentioned has upsampling via ASIO but due to GUI limitations and lack of Parametric EQ, I am trying to upsample to 352K all my content within windows own sound settings for the DAC.
Anyways, your opinion and guidance is really appreciated. Thanks agian
There seems to be a newer version of the es9038 board on ebay. Better?
There is this new board on ebay. ES9038 Q2M DAC DSD Decoder Board Supports IIS DOP 384KHz DSD512 + OLED | eBay It came out in 2020 apparently. It looks like it was made by the same people as the original recommended board. Is it any better?
For a person who already has an amanero, trying to spend less than 100 bucks to get things working, is the new board in that link i posted above the best bet?
I just got back to USA and trying to get some decent sound working again. I will get a cheap one for now, then go for something better asap.
Thanks a lot.
Philip
There is this new board on ebay. ES9038 Q2M DAC DSD Decoder Board Supports IIS DOP 384KHz DSD512 + OLED | eBay It came out in 2020 apparently. It looks like it was made by the same people as the original recommended board. Is it any better?
For a person who already has an amanero, trying to spend less than 100 bucks to get things working, is the new board in that link i posted above the best bet?
I just got back to USA and trying to get some decent sound working again. I will get a cheap one for now, then go for something better asap.
Thanks a lot.
Philip
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Windows sample rate conversion is done on the fly, and not all that well well either. If you like it though, that's all that matters.
The software I was talking about is HQ Player. It has a GUI and there is a free trial version that I use for testing. It will run for 30-minutes but then has to be restarted. Not a problem for testing. Great sound possible from it.