Hello,
as I promissed just to share with you concept from YU3MA forum, this is pulse densinity modulated H bridge power dac driven by dsd64, in short it's an full bridge class D direct digital power amplifier pulse densinity modulated, contain no opamps... etc just directly flow DSD bits to the full bridge, more comparable to an water flow boiler with diference boiler flow hot water but this one flow dsd bits. : ) Tested up to dsd256, it might work on dsd512 too? Concept contain variable power supply as a volume control, 1.25V to 5V range. You need Amanero usb combo and you need DSD tracks in order to play sound trought this dac. You will be surprised by the huge dynamics and holographic unchanged and detailed sound! The power of this dev concept is in the range of 3 to 5 watts and I do not recommend more, you simply need to first adjust the current with CC pot by shorting +5V at the one of the 8 capacitors for example C165 to gnd with an ameter until your ameter display value close to 1A, than you are ready for sound testing. Here is soome pictures and videos and more details about further concept . Its fully diferential! Optimised for 8 ohm speakers! Not measured but I have bought Cosmos ADC and when I finish some concepts and when I get ready for measurement I will do it, hope somebody do it allready. Gerber, bom and schematic is in atachment. Please pay atention to R72 resistor, change it for 2mA, ohm law yuor input dc voltage and calculate resistor value for 2mA! Enjoy!
as I promissed just to share with you concept from YU3MA forum, this is pulse densinity modulated H bridge power dac driven by dsd64, in short it's an full bridge class D direct digital power amplifier pulse densinity modulated, contain no opamps... etc just directly flow DSD bits to the full bridge, more comparable to an water flow boiler with diference boiler flow hot water but this one flow dsd bits. : ) Tested up to dsd256, it might work on dsd512 too? Concept contain variable power supply as a volume control, 1.25V to 5V range. You need Amanero usb combo and you need DSD tracks in order to play sound trought this dac. You will be surprised by the huge dynamics and holographic unchanged and detailed sound! The power of this dev concept is in the range of 3 to 5 watts and I do not recommend more, you simply need to first adjust the current with CC pot by shorting +5V at the one of the 8 capacitors for example C165 to gnd with an ameter until your ameter display value close to 1A, than you are ready for sound testing. Here is soome pictures and videos and more details about further concept . Its fully diferential! Optimised for 8 ohm speakers! Not measured but I have bought Cosmos ADC and when I finish some concepts and when I get ready for measurement I will do it, hope somebody do it allready. Gerber, bom and schematic is in atachment. Please pay atention to R72 resistor, change it for 2mA, ohm law yuor input dc voltage and calculate resistor value for 2mA! Enjoy!
Attachments
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Yes sure! Important is that dsd need to be on input, I recommend dsd64 up to dsd256, I'm on dsd64 and I believing thats optimal because of switching frequency inside H bridge is allready huge with dsd64. Its important to have booth mute and DSD_ON otherwise you will get pops and clicks and also you might kill something on pcb without it, so I recommend Amanero combo since it allready have all that functions! This is just development version, further concepts is more complicated, ganFet based. But even dev version produce huge sound, I was shocked on first note with huge sound and power delivered from just 3-5 watts 
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It can be comparable to a flow water heater boiler, water flows through the flow water heater boiler, and dsd bitstream flows here
We are trying to design post LC filter digital feedback, thats not an easy task right now but my hope somebody from this great forum give here some great idea! Migh be DDPD used for something other, for example an SDR transmiter?
We are trying to design post LC filter digital feedback, thats not an easy task right now but my hope somebody from this great forum give here some great idea! Migh be DDPD used for something other, for example an SDR transmiter?
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My theory how it can be done:
1. https://www.mathworks.com/help/signal/ug/measuring-signal-similarities.html'
2. https://makeabilitylab.github.io/physcomp/signals/ComparingSignals/index.html
3. or something similar which is able to compare two diferent signals
Problem is all that things need to be ultra fast in range few nano secconds. In short we need something ultra fast e.g. an 24bit ultra fast adc to convert post lc filter analog signal to digital,, than compare signals similarity for determining error diference, and last correct input bitstream dsd bits on the fly. If anybody have idea please let us know!
1. https://www.mathworks.com/help/signal/ug/measuring-signal-similarities.html'
2. https://makeabilitylab.github.io/physcomp/signals/ComparingSignals/index.html
3. or something similar which is able to compare two diferent signals
Problem is all that things need to be ultra fast in range few nano secconds. In short we need something ultra fast e.g. an 24bit ultra fast adc to convert post lc filter analog signal to digital,, than compare signals similarity for determining error diference, and last correct input bitstream dsd bits on the fly. If anybody have idea please let us know!
Sure! USB in my opinion the best input source. This one from OP produce unbelievable dynamic and lifelike sound, I do not have something to compare, please build! In month-two new concept based on ganFet will be on my bench for test, all is allready designed and pcb's is on manufacturing proces, it will give 2x200W and if it become close to our concept it will be top! : )
Hi yes, here is. One great thing which maybe I didn't menrioned here is: DSD is not getting atenuation when we have volume control at power supply level! That giving us full resolution without resolution lost while on low level volume! Thats a special feature here and realy great feature! This full bridge power dac is amazing, sadly still nobody built it, you must hear it!!! The only thing for check is dead time adjustement which I am curently unable to fine tune because I don't have right equipment for that, need to be speacial care done to RC delay near D2, D3, D4, D5 and eventualy fine tuned post bridge LC filter, we have simulated and added optimal filter but it deserve fine tuning too! Even without any modification to this circuit sound is amazing!
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Not right now, but I have collected some equipment needed for this, got Cosmos ADC and also made diy dummy load with aux0025 filter and atenuator, but right now don't have good osciloscope, need to buy one better soon. I will do some Cosmos measurement till after I finish some big brother projects related to our DDPD, its ganFet based, have some problems with it, almost 20 days working on it to solve some problems, till after finish I will do measurement on our mini DDPD! Measurements will not change the excellent sound much, they will possibly help to adjust the ddpd even better. I'm very happy that I don't have a single opamp in the audio chain, everything goes directly like water in a flow boiler and really smooth and extremely dynamic huge sound! : )
Edit: since this is fully digital concept problem is measuring it, for measuring I need conversion from ref sgnal to DSD and thats a problem, I must finish frontend first (DDPD frontend) ! Problem is ref signal from REW, Rew send signal trought usb but problem is DDPD reguire DSD! So my choice is Amanero as input for Rew and CT7302PL as converter for DSD needed for DDPD, tats all I must done first before think to do measurement.
Edit: since this is fully digital concept problem is measuring it, for measuring I need conversion from ref sgnal to DSD and thats a problem, I must finish frontend first (DDPD frontend) ! Problem is ref signal from REW, Rew send signal trought usb but problem is DDPD reguire DSD! So my choice is Amanero as input for Rew and CT7302PL as converter for DSD needed for DDPD, tats all I must done first before think to do measurement.
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Hi Savan ... thanks for your feedback & good luck in your trials & investigations ... Cheers, Jesper
P.S.: If you use HQPlayer and JLSounds board you get quite good oscillators and DSD out as well. Plus digital isolation & the ability to play PCM 768 kHz should you be interested in that.
... Cheers, JesperP.S.: If you use HQPlayer and JLSounds board you get quite good oscillators and DSD out as well. Plus digital isolation & the ability to play PCM 768 kHz should you be interested in that.
I have made my own Amanero, isolated, LT3042 reg, the best input source for my equipment is trought usb definitelly, isolator should be between mcu and cpld next time, and now investigating CT7601 inside DDPD frontend now isolated with isousb211 480Mbps, made mistaqe with isousb111 which is max dsd256 and now need new pcb : ( Thats why measurements on ddpd will be late
