flowerpot Posted December 28, 2014 Posted December 28, 2014 Just completed this pure DSD DAC project.... Last year i completed a NOS PCM DAC 384Khz using AD1865... With DSD gaining a lot of popularity i thought i will go for DSD Dac this time... There are a lot of implementation of DSD dac in the market... many uses off the self chips like the sabre ES9018... some uses FPGA in many high end dac, PS direct stream, Chord, Playback design, EMM labs just to name a few... The concept of DSD is rather interesting... in theory all you need is just a low pass filter and thats it. Just google it...It makes you wonder why go all the trouble to make things complicated... Designers that uses FPGA make use of its processing powers and their own proprietary algorithm for upsampling/filters etc, so far this seems to gaining more traction than using off the shelf chips... There are also purist that who does not use any dac/fpga chips, just a implement a low pass filter, the lampizator dsd is one of them... interestingly there are also some chips that has direct dsd function, like the top of the line CS4398 where the DSD signal can directly go to a switch capacitor which essentially is a low pass filter... i was planning a pure DSD dac as well with just low pass filter... the idea is to let the PC do all the heavy lifting(upsampling, filter implementation), HQplayer and jriver both is good for this, advantage of this is also software is constantly improving and evolving, rather than always chasing the hardware... the dsd dac just ensure the signal is isolated, very low jitter and goes to a low pass filter that all... In the mist of my research, i found a rather interesting concept call the DSD principle board from Electrart...you have to hand it to the Japanese to come up with something like this. And they keep the good stuff in Japan... The DSD principle board is already a 2/3 year old concept, but i only discover it recently... its actually just a low pass FIR filter board... And FIR filter can be easily implement using flip flops, just a delay signal with its gain coefficient. Juts google and you can see how easy it is... So all you need is the I2S (DSD) signal, feed to the FIR low pass filter and you are done... This principle board is actually no longer on sale... but i was lucky a Japanese guy who frequent diyaudio is willing to sell this board to me... like they say you never know if you never ask... this board is a 8 tap FIR filter, which is just a few flip flops and resistors, differential to single ended, so for stereo you need 4 octal flip flops... this project i uses a Joro USB to I2S board with isolation, reclock with femto clock crystal 957, isolation again and feed to the FIR filter... there is a on board i/v and a differential to SE stage then to RCA... Kenneth Lau OCC silver-plated copper transformer. mundorf and duelund wires are used for the signals wiring... shunt +/- 15V for the output stage...ADM7150(wii be change to 5V shunt later) for the 5V FIR filter.... Here is the completed dac and it sounds pretty amazing... :) now I'm quite pump up to complete another DSD dac using 32 tap FIR filter and just a pair of output transformer... ;D So there you have it.... no off the shelf dac like ES9018, no FPGA... just a low pass filter, similar to Lampizator DSD.. you cannot get any simpler than that... All you need is USB to I2S board, a DSD principle board with all the required power supply and you are done... A PURE DSD dac... plain and simple... and it sounds pretty awesome.... :) 1
DIYer Straits Posted December 28, 2014 Posted December 28, 2014 W :o W! Great job! this is really hard core, man. Where did you get the PCBs? Custom jobs? Too bad they're not available anymore... http://fpga.cool.coocan.jp/electrart/pcm2dsd.html
Guest AndrewC Posted December 28, 2014 Posted December 28, 2014 Wow, nice! I bet it sounds amazing. You should benchmark it against some commercial SACD players to hear just how good this thing is ;)
j45yip Posted December 29, 2014 Posted December 29, 2014 ...nice job, flowerpot. i see you're a music streamer. what make you choose the Joro over the waveIO USB to I2S board? is the diff to SE analog output via opamps? too bad i don't do streaming :D
pichalobang Posted December 29, 2014 Posted December 29, 2014 Great effort by TS. Good job for someone who only started DIY only not too long ago.
Myint67 Posted December 29, 2014 Posted December 29, 2014 Hi bro, Where r u buy steel transformer cover ?
flowerpot Posted December 29, 2014 Author Posted December 29, 2014 W :o W! Great job! this is really hard core, man. Where did you get the PCBs? Custom jobs? Too bad they're not available anymore... The electrart board is from a Japanese guy who frequent diyaudio, i just ask where he got the board and he says he can sell me his board. The red PCB which is the 32 tap FIR board, its also from the same Japanese guy, i just ask if he can help me to get and he say yes... The red PCB is actually from another Japanese guy Yana San.... You can google DSD principle board you should be able to find it. I did talk to Yana San but he says he will not ship overseas... Mine is V1.8, i think there is a newer version just out. If you have a Japanese friend maybe they can help... Impressive bro! Bro this is really simple DSD DAC and its so simple you will be laughing silly why nobody does it... and its really a simple circuit... With electrical background its easy peasy... And it sounds really good... Wow, nice! I bet it sounds amazing. You should benchmark it against some commercial SACD players to hear just how good this thing is ;) I don't have a SACD player, nor do i own any high end dac... The most expensive dac i have is the LKS Audio dual ES9018 dac, which i mod almost everything, from transformer, regulator, IEC, temto clocks etc... its my reference dac... you can find more infor from HK forums... apparently it hold its own against some of the best dacs out there after modding... And this pure DSD dac is quite close to the LKS dac... i have not done any critical listening but initial impression is very good indeed... also test is done on headfi... cos i fried my diy amp so now I'm left with headfi setup... ...nice job, flowerpot. i see you're a music streamer. what make you choose the Joro over the waveIO USB to I2S board? is the diff to SE analog output via opamps? too bad i don't do streaming :D waveIO did not have DSD when i bought the Joro board... also Joro board has a add on for external clock, which i added... clocks are the crystek 957 which is one of the best clock you can buy... of course there are better clocks but those cost few hundreds which i have no budget for it... and Joro also has reclock and isolation so the output is very very low jitter and isolation from the outside world... Diff to SE is via opamp... will be change to a discrete type opamp when the part i just ordered arrived.... yes I'm on computeraudio.... if you know what you are doing... computeraudio can be better than using a SACD/CD player... Hi bro, Where r u buy steel transformer cover ? Those are already sealed... The transformer is from Kenneth Lau in HK... he makes many power supply, Lumin just to name one... his transformer/power supply is top notch... the one i am using is the OCC silver-plated copper transformer with the cover...this is one of his best transformer... ~S$200 each... hopefully tonight i can finish up my 32 tap DSD board... This one i got high hopes it will be awesome... :)
garbage1624705950 Posted December 30, 2014 Posted December 30, 2014 nice to see this level of DIY! :)
naimster Posted December 30, 2014 Posted December 30, 2014 Very nice. How do you setup your streamer? Pure DSD means it will it doesnt do PCM at all and you have to have some conversion to DSD when playing PCM content?
flowerpot Posted December 30, 2014 Author Posted December 30, 2014 Very nice. How do you setup your streamer? Pure DSD means it will it doesnt do PCM at all and you have to have some conversion to DSD when playing PCM content? Hqplayer, jriver, foobar2000 all can do real time PCM->DSD... As mention I let the PC/Mac do all the heavy lifting job(upsampling/noise shaping/filter)... The dac just need to do 1 job... And that is to convert digital to analog which is just a LPF...Nothing else...
flowerpot Posted December 30, 2014 Author Posted December 30, 2014 Just completed another pure DSD dac base on 32 tap FIR filter... Tested it... Got sound... :) But because its direct to a output transformer... Sound seems '"weak" on the bass and dynamics... Could be also the output impedance is too high...Probably I need to add a buffer stage or connect to a tube base input... Will post pics later... Now let it burn in abit before I start listen again...
flowerpot Posted January 5, 2015 Author Posted January 5, 2015 Post some pics of the other pure single bit DSD dac using just a 32 tap FIR filter. See how simple it is... After running in, the sound will surprise you :) USB->I2S(DSD)-->FIR filter-->lundahl transformer acting as i/v. Power supply is a salas design shunt built for digital circuit. Overall dac USB board from Sonore (isolated and reclock with crystal 957) 32 tap FIR filter (just using flip flops and resistors) Lundahl transformer 1
MLGrado Posted January 21, 2015 Posted January 21, 2015 Hi all... first post here.. I find this a fascinating project! What you are doing here is very similar to the Signalyst Open Source DAC. He uses a 32 tap filter via shift registers and equally weighted switches. Burr Brown is also similar, but is just an 8 bit long delay, with unequally weighted switches. And the lampizator, I am pretty sure also uses this simple, moving average FIR filter. If you look at its design, it says the first filter stage is 'solid state digital'. That to me says it must be a moving average FIR via delays and switches. This kind of filter can be thought of as analog, digital, or hybrid analog/digital. Myself I like to see it as a hybrid analog/digital. 1
Audio Posted January 21, 2015 Posted January 21, 2015 Everything sounds nice when you use the Lundahl transformers!!! Where is the switching device? The one before the FIR filter? (Audio)
MLGrado Posted January 21, 2015 Posted January 21, 2015 Also consider Bruno Putzey's latest project... uses PWM rather than PDM(DSD), but conceptually very, very similar... "In my DAC, the total number of every such cycle is 32 samples. So the PWM signal cycle repeats at the rate of 3.125MHz, and in that interval you have 32 samples, so the bit-clock rate is 100MHz. So there’s this 32-stage shift register that clocks in this data at a corresponding rate of 100MHz, and each of those stages sees the full PWM signal. And you add the 32 outputs together with 32 resistors. Each of those stages alone would, in principle, suffice to convert that signal into analog, but because you’re making a running average of a complete cycle in there (for each bit of the cycle you shift out, there is an equivalent bit of a new cycle that you shift in), the big square-wave part of the PWM signal is being averaged out, and all you are actually left with is just the audio content and a much-reduced amount of out-of-band noise." http://www.ultraaudio.com/index.php/features-menu/general-interest-interviews-menu/465-searching-for-the-extreme-bruno-putzeys-of-mola-mola-hypex-and-grimm-audio-part-two
flowerpot Posted January 29, 2016 Author Posted January 29, 2016 New toy ;D Many thanks to a friend who help get this board from Japan. http://yanasoft.jp/yana/ak4137_p2d.html Another Dac less DSD project ;D Using this to upsample to 256DSD and apply a LPF... This time round maybe just a analog LPF or just a transformer out acting as a LPF... Hopefully i get to start this in Apr and made it to this year NOISing... :) 1
j45yip Posted February 1, 2016 Posted February 1, 2016 ...starting early is always good. give you more time to make changes if improvement can be made. looking forward to it, flowerpot :)
naimster Posted February 1, 2016 Posted February 1, 2016 I have the kit too from the same friend...unfortunately I doubt I will ever complete it this year due to heavy committments. :(
flowerpot Posted February 2, 2016 Author Posted February 2, 2016 I figure you might have it as well lol... I did not asked him...Let me be the guinea pig to try it out for both of you... I have the kit too from the same friend...unfortunately I doubt I will ever complete it this year due to heavy committments. :(
flowerpot Posted January 6, 2017 Author Posted January 6, 2017 For those who dislike using USB... Using the BBB as NAA( for those using HQPlayer), together with the botic driver, the BBB is able to output I2S/DSD direct... so no XMOS/USB, just through network connection you get DSD... the DAC sort of becomes a network player but you still need HQPlayer as a source... removing USB from the system... Stable playing DSD512... I design a daughter board for the BBB, the board comes with isolation, reclock and balance output. The board have a few mistakes(Pin41 instead of pin 29 for DSD). Anyway the initial plan was to built a new DSD dac with tube output, but i already have 2 DSD dac so i kinda hesitant to make another one. So i decide to take the worst of the DSD dac and test out the BBB... I was presently surprise by the sound... but then again i have low expectations... :D Next step would be to change the NDK clock to the custom Laptech clock which is suppose to be alot better than the femto clocks from Crystek and built a new Dac using a newly built 32 tap FIR DSD board... Using this DSD DAC to test out the BBB and the daughter board... those at last yr NOISing would have listen to this DAC... and it sound even better than before... ;D some close up on the BBB and daughter board... The Laptech crystal and the newly built 32 tap dsd board... 1
flowerpot Posted January 15, 2017 Author Posted January 15, 2017 Change the clock to the lap tech(TWTMC) AT Cut 45.1584Mhz... Sounds good ;D
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