The 1.2v regulator issue has been discussed before. It turns out the mobile Q2M chip has an internal 1.2v regulator, so it does not need an external regulator. No one seems to know why some of the Chinese boards were made with external regulators anyway.
EDIT: Hey, while we are talking, does anyone have any mod updates and or build picture to share? We like to see when people make progress out there!
EDIT: Hey, while we are talking, does anyone have any mod updates and or build picture to share? We like to see when people make progress out there!
280 pages is not light material
It would be useful to compile relevant mods maybe into new thrad or make some kind of reference to mod compilation.
@bozoc, From time to time I have attached a file listing posts that are hoped to be of possible interest for modding purposes. I will do so again here.
EDIT: Maybe I should add this one to the list as well, it talks about some experimental output filtering: http://www.diyaudio.com/forums/digital-line-level/314935-es9038q2m-board-238.html#post5523698
EDIT 2: There may be some I missed too when trying to keep a list. Sometimes there are follow up questions and answers. Also, I think in the last few pages before this one there may be a few posts of possible interest. Perhaps it would be useful for the purposes of keeping a list that isn't too long if people would say which posts they find most useful. Then maybe we could pare down the list, or have a brief summary version. I don't know, really depends on whatever people think.
EDIT: Maybe I should add this one to the list as well, it talks about some experimental output filtering: http://www.diyaudio.com/forums/digital-line-level/314935-es9038q2m-board-238.html#post5523698
EDIT 2: There may be some I missed too when trying to keep a list. Sometimes there are follow up questions and answers. Also, I think in the last few pages before this one there may be a few posts of possible interest. Perhaps it would be useful for the purposes of keeping a list that isn't too long if people would say which posts they find most useful. Then maybe we could pare down the list, or have a brief summary version. I don't know, really depends on whatever people think.
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Please see my post in this topic at #1584 (and #2039)
http://www.diyaudio.com/forums/digital-line-level/314935-es9038q2m-board-159.html#post5473513
4.7 uF X7R works better than X5R.
http://www.diyaudio.com/forums/digital-line-level/314935-es9038q2m-board-159.html#post5473513
4.7 uF X7R works better than X5R.
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Thanks
I try to make a document about the simplest modifications and i will add this mod
Serge
My board is 1.06 which came with the external regulator. It is maybe the one thing I have never modded on this dac and it never caused a problem. Don't know about boards that did not come with a regulator. But, I don't see a need to do a mod there if it isn't needed. In this case need would mean that there is a problem with DVDD regulator stability. Of course, doing the mod if not needed won't hurt either. It's just that there are other mods that have a lot more effect on sound quality, at least if my board is any example.
By the way, it could be that Allo Katana 1.2 will be along for review without too much further delay. I received a query as to whether I was still interested, to which I replied in the affirmative. Hopefully, there will be something to share soon regarding that particular version of a an ES9038Q2M board. Always interesting to see what people can do with these dac chips.
Sometimes people ask if there are ebay or other boards that can be used to help simplify modding dac boards. Just found a differential filter board that looks like it could work for the differential summing stage that follows I/V stages: LME49710 filter board - I2S over USB Audio There is a schematic available that shows the filter components: http://jlsounds.com/uploads/LME49710_schematic.pdf
It occurred to me that I left out somethings important in the list of mods a few posts up from here, the first of which is not a mod, but rather a link to important documents and schematics at the ESS website:ESS Technology :: Downloads
The most important document there is probably this one: http://www.esstech.com/files/4514/4095/4306/Application_Note_Component_Selection_and_PCB_Layout.pdf
In addition, I wanted to post the output stage schematic I used for my board that goes along with the pictures shown with the modding descriptions, so that is attached below along with the dac chip pinout. There is no schematic of power regulation mods, but I can describe those in more detail if needed.
The schematics for AVCC power, required component types, and layout rules are all shown the ESS documentation.
If there are any questions about anything shown in the modding pictures and descriptions, such as components used, etc., please ask if not clear and I will try to clarify in as much detail as may be needed.
Also, the foregoing is in response to occasional requests to reduce of the burden of having to read through the whole thread to see what the mods are. If there is still a feeling that it needs to be organized into a new, shorter thread maybe that could be done. I would need some feedback before doing that though, as it would probably be a lot of work which once people saw how much work was involved, they would never look at it again. If so, not sure it would serve much good purpose to have it.
The most important document there is probably this one: http://www.esstech.com/files/4514/4095/4306/Application_Note_Component_Selection_and_PCB_Layout.pdf
In addition, I wanted to post the output stage schematic I used for my board that goes along with the pictures shown with the modding descriptions, so that is attached below along with the dac chip pinout. There is no schematic of power regulation mods, but I can describe those in more detail if needed.
The schematics for AVCC power, required component types, and layout rules are all shown the ESS documentation.
If there are any questions about anything shown in the modding pictures and descriptions, such as components used, etc., please ask if not clear and I will try to clarify in as much detail as may be needed.
Also, the foregoing is in response to occasional requests to reduce of the burden of having to read through the whole thread to see what the mods are. If there is still a feeling that it needs to be organized into a new, shorter thread maybe that could be done. I would need some feedback before doing that though, as it would probably be a lot of work which once people saw how much work was involved, they would never look at it again. If so, not sure it would serve much good purpose to have it.
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After all this time I finally found a way get my 1kHz notch filter working along with my steel shielded file server dac case so I could do some very fine tweaking of harmonic distortion compensation. The steel case was needed due the fairly high levels of radio waves here up on top of the hill where I am located, not too far from three airports.
Anyway, Sabre dacs have two digital adjustments for harmonic distortion compensation, one for 2nd harmonic, and one for 3rd. The two adjustments affect both channels and all operating modes. The full range of adjustment is controlled by a 16-bit signed integer, with the midpoint, zero, giving no correction at all.
ESS says the adjustment can be used to compensate for non-linearity in the analog output stage. It looks like the output stage here is probably pretty linear to begin with, as both adjustments came in pretty close to zero. 2nd harmonic was minimized with a setting of 5, and 3rd harmonic came in with a optimum setting of -6. It looks like I got an improvement of around 2dB for each harmonic using those settings. Although a 2dB improvement down close to -120dB may not seem like much, I think there it was kind of just audibly noticeable. I will do some more A/B listening with it over the next few days to get a better idea of how much effect there is.
Although my goal this time around was just to find minimum distortion settings, sometime later I will try to go back and get calibrated measurements of the two harmonic levels for a 1kHz test tone (unfortunately, I only have the one notch filter at this point).
Anyway, Sabre dacs have two digital adjustments for harmonic distortion compensation, one for 2nd harmonic, and one for 3rd. The two adjustments affect both channels and all operating modes. The full range of adjustment is controlled by a 16-bit signed integer, with the midpoint, zero, giving no correction at all.
ESS says the adjustment can be used to compensate for non-linearity in the analog output stage. It looks like the output stage here is probably pretty linear to begin with, as both adjustments came in pretty close to zero. 2nd harmonic was minimized with a setting of 5, and 3rd harmonic came in with a optimum setting of -6. It looks like I got an improvement of around 2dB for each harmonic using those settings. Although a 2dB improvement down close to -120dB may not seem like much, I think there it was kind of just audibly noticeable. I will do some more A/B listening with it over the next few days to get a better idea of how much effect there is.
Although my goal this time around was just to find minimum distortion settings, sometime later I will try to go back and get calibrated measurements of the two harmonic levels for a 1kHz test tone (unfortunately, I only have the one notch filter at this point).
Perhaps oddly, there still appear to be some people reading this old thread. But, very little going on in way of writing. It's well known in forums that only a few percent of people post, and the vast majority choose to read along only. That being the case, surely there must be a few people who have done some ES9038Q2M modding that we could talk about and see some pics of?
Also, seems likely there are some people waiting for parts orders to arrive from China. It can take a few or even several weeks in some cases. Maybe we could have show of hands from people who are still interested, but just waiting for deliveries?
In addition, I am trying to see if I can find out any more about what is going on with Katana dac revisions and upgrades. Maybe we will hear something early this week, although not sure about that quite yet. Of course, while Katana improvements continue with the stated goal of making it very exceptional dac, the best RPi dac out there (they say), I keep making little bits of progress with my modded Chinese dac. One might not think so, but another couple of dB here and there of reduced distortion adds up and it just shows there is more than one way to make a not-too-bad dac, I guess.
In that regard I was recently reminded that it was decades ago when Walt Jung made the observation that with dacs, everything matters. Nothing has changed there, it sure seems like. Every little thing thing that gets fixed or improved makes a difference and the only dac I know of personally where everything that was known to be fixable was actually fixed, and that was of course with Benchmark DAC-3. Interestingly, there is a new review of the top of the line version Border Patrol dac at Stereophile here: BorderPatrol Digital to Analogue Converter SE | Stereophile.com
Border Patrol dac is of course an example of an expensive 16-bit NOS dac, and on the second page of the review it was compared in quite a bit of detail to what I guess they thought was most polar opposite dac they could find, which happens to be Benchmark DAC-3. Many of the things about DAC-3 that seem very good to me were things the reviewer apparently didn't want in a dac. Those same kinds of things are also largely characteristic of the most recent Sabre dacs in general (although DAC-3 probably does the Sabre dac thing best, IMHO of course). But, that's kind of where modding the Chinese dacs in this thread leads to at one extreme: a very accurate, very dynamic, great deep powerful bass, pulsating percussion, realistic instruments, real sounding cymbals, etc., everything just like the record was engineered to sound like, and that the artist signed off on as their artwork, type of dac. Yet somehow the Border Patrol dac reviewer wanted something else, a more distorted view of the artist's vision, but adjusted more to the taste of the reviewer. I don't know about that, but if by chance that is what some DIYer's reading would prefer, this may not be the best thread for it. Sabre dacs just don't do that NOS thing as well as an actual NOS chip can, IMHO as always.
For those folks that do want a great sounding Sabre type dac, I would certainly encourage everyone to keep modding. That's the reality with dacs, for better or for worse, everything matters. The more you do on it the more you have to proud of in terms of DIY accomplishment, something very good to enjoy, and something to amaze your friends with. Just don't quit is all, it only keeps getting better as you go. Always a reason to smile as another little thing is fixed, and you hear that improved sound for the first time!
Also, seems likely there are some people waiting for parts orders to arrive from China. It can take a few or even several weeks in some cases. Maybe we could have show of hands from people who are still interested, but just waiting for deliveries?
In addition, I am trying to see if I can find out any more about what is going on with Katana dac revisions and upgrades. Maybe we will hear something early this week, although not sure about that quite yet. Of course, while Katana improvements continue with the stated goal of making it very exceptional dac, the best RPi dac out there (they say), I keep making little bits of progress with my modded Chinese dac. One might not think so, but another couple of dB here and there of reduced distortion adds up and it just shows there is more than one way to make a not-too-bad dac, I guess.
In that regard I was recently reminded that it was decades ago when Walt Jung made the observation that with dacs, everything matters. Nothing has changed there, it sure seems like. Every little thing thing that gets fixed or improved makes a difference and the only dac I know of personally where everything that was known to be fixable was actually fixed, and that was of course with Benchmark DAC-3. Interestingly, there is a new review of the top of the line version Border Patrol dac at Stereophile here: BorderPatrol Digital to Analogue Converter SE | Stereophile.com
Border Patrol dac is of course an example of an expensive 16-bit NOS dac, and on the second page of the review it was compared in quite a bit of detail to what I guess they thought was most polar opposite dac they could find, which happens to be Benchmark DAC-3. Many of the things about DAC-3 that seem very good to me were things the reviewer apparently didn't want in a dac. Those same kinds of things are also largely characteristic of the most recent Sabre dacs in general (although DAC-3 probably does the Sabre dac thing best, IMHO of course). But, that's kind of where modding the Chinese dacs in this thread leads to at one extreme: a very accurate, very dynamic, great deep powerful bass, pulsating percussion, realistic instruments, real sounding cymbals, etc., everything just like the record was engineered to sound like, and that the artist signed off on as their artwork, type of dac. Yet somehow the Border Patrol dac reviewer wanted something else, a more distorted view of the artist's vision, but adjusted more to the taste of the reviewer. I don't know about that, but if by chance that is what some DIYer's reading would prefer, this may not be the best thread for it. Sabre dacs just don't do that NOS thing as well as an actual NOS chip can, IMHO as always.
For those folks that do want a great sounding Sabre type dac, I would certainly encourage everyone to keep modding. That's the reality with dacs, for better or for worse, everything matters. The more you do on it the more you have to proud of in terms of DIY accomplishment, something very good to enjoy, and something to amaze your friends with. Just don't quit is all, it only keeps getting better as you go. Always a reason to smile as another little thing is fixed, and you hear that improved sound for the first time!
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From the article:
The tda1543 is NOT an R-2R chip. It is NOS (though you could feed it an over-sampled signal, e.g. done upstream in software); and it is indeed not a delta-sigma type. But R-2R it is not.
On the last page, even the manufacturer gets it wrong, "Despite inferior measurements, there is a good argument to be made that R-2R NOS DACs are more accurate than delta-sigma DACs..." (Makes similar comments on the actual product page.)
I wish the article had some pics with the case cover off.
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Don't know about that particular model, but there is picture of one version out there I will post below. No wonder it doesn't sound like DAC-3, or a modded Chinese dac for that matter. I would say it looks closer to one of our modded dacs though. One difference is I couldn't use a wooden box for my modded dac because the LME49720 opamps are probably best put in a steel box just in case of any DECT phone base stations nearby.
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Nowadays its very common for those without EE knowledge to use 'R-2R' as a drop-in replacement for 'multibit'. They haven't learned that there's a variety of multibit DACs out there and R-2R is but one way to implement a multibit DAC.
What I found most interesting about the comparison between Benchmark and BorderPatrol were these couple of remarks :
Through the BorderPatrol DAC SE the horns emitted burnished corporeal tones saturated in color and vivacious in temperament. The Benchmark's horns were more gray and generic.
..the DAC3 got the pounding of the drums and the energy of the twang from Eddy's Gretsch gee-tar—but it truncated the reverb-drenched space of the recording, robbing me of a secret aural glimpse inside the rusty steel 2000-gallon water tank used as the echo chamber for this million-selling single.
As for your alleged 'smartypants'ness @Matt oh the irony, the irony
Hi Mark, i have connected the SRC board with amanero , changed the 7805 regulator to LM1086 (made some improvement in sound IMHO),changed the opamp to ths4032CD (my girlfriend said the sound became clearer but im not so sure) , im in the process of connecting a separate power supply for the CLOCK now, and will change the clock to crystek once it arrives.
after that im planing to do the AVCC circuit in a week or 2.i will try to post a pic tonight.
thanks for all the tips, and keep up the good work!
) , im in the process of connecting a separate power supply for the CLOCK now, and will change the clock to crystek once it arrives.after that im planing to do the AVCC circuit in a week or 2.i will try to post a pic tonight.
thanks for all the tips, and keep up the good work!
@paulmarinis, Thank you for the update! Hope you have fun with the project as you work your way through the mods of increasing complexity. I think you will be amazed by how it turns out if you have never heard a really good dac before. Looking forward to seeing the pictures when you have some you can share with us.
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Um...
But what you , Braxy (like matt), CONSISTENTLY fail to produce are quick and accurate and REFERENCED answers to open questions ... like what dacs, like the classic Philips family, are:
Philips TDA1541A d/a converter - DutchAudioClassics.nl
Roughly: " binary weighted current network / dynamic current divider"
Simply remarking things like "1543 is not R2R" or even your garrulous confusion above is ... well ... confusing.
Nowadays its very common for those without EE knowledge to use 'R-2R' as a drop-in replacement for 'multibit'. They haven't learned that there's a variety of multibit DACs out there and R-2R is but one way to implement a multibit DAC.
What I found most interesting about the comparison between Benchmark and BorderPatrol were these couple of remarks :
Through the BorderPatrol DAC SE the horns emitted burnished corporeal tones saturated in color and vivacious in temperament. The Benchmark's horns were more gray and generic.
..the DAC3 got the pounding of the drums and the energy of the twang from Eddy's Gretsch gee-tar—but it truncated the reverb-drenched space of the recording, robbing me of a secret aural glimpse inside the rusty steel 2000-gallon water tank used as the echo chamber for this million-selling single.
As for your alleged 'smartypants'ness @Matt oh the irony, the irony
But what you , Braxy (like matt), CONSISTENTLY fail to produce are quick and accurate and REFERENCED answers to open questions ... like what dacs, like the classic Philips family, are:
Philips TDA1541A d/a converter - DutchAudioClassics.nl
Roughly: " binary weighted current network / dynamic current divider"
Simply remarking things like "1543 is not R2R" or even your garrulous confusion above is ... well ... confusing.