I do not know what happened with the hyperlink to the actual attachment, it usually gets copied across when I click on "Quote"
The attachment is in your post #19.
The attachment is in your post #19.
Ok, I see, there is two regulators, U40 is LT3042 high CMRR/PSRR regulator, and U3 suplied from U40, I don't found any isue there, DC is very clean!
Volume control with + and - buttons is an imperfection. Rotary volume control is ergonomic.
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Could use a military bearing.. no wait that was the Millennium TaCT.
The TaCT had shielding around the switching units IIRC (I almost bought one but decided against it) simply because it starts radiating due to the high power switching.
The TaCT had shielding around the switching units IIRC (I almost bought one but decided against it) simply because it starts radiating due to the high power switching.
Rotary is ok but our alu enclosure is not enought for ddpd, digital supply control, connectors...etc, simply no room for rotary encoder! Pic MCU will control button press, just simply preess and hold button is enought + we have ir led for remote control, the most time you will no need buttons at all, just use remote control to control it. Pic will deep sleep all the time and awake on button/ir triger. Back panel contain 4 SMA connectors, 1 DC connector, 4 bannana jacks for speakers, alu enclosure is simply almost full! I'm struggling to fit all of this into this little box!
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Yes, I'm trying to fit all this! Edit: I ordered some parts so everything is going soo slowly because waiting parts, but I am sure it will fit, my persistence! 🙂
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Looking for good and silent as possible buttons, which one you reccomend? I thinking to try this one -> https://www.lcsc.com/product-detail/Tactile-Switches_Omron-Electronics-B3SL-1022P_C86708.html The ideal for this project would be non tactile mode rubber buttons as like most remote control have them, but I don't have idea what is the name of it and where to get them.
I have in work something better, its working from zero volt! Thats important to have volume control based on variable power supply so DDPD always working in full resolution without any software atenuation. Gan technology for the next, yes definitely the next project will be 200-300 wats based on Gan technology!
Done mini version, a bit tight but all done! Our small version simply deserve aluminium enclosure, I will let you know the result when test pcb's come to me and when all get asembled!
Done mini version, a bit tight but all done! Our small version simply deserve aluminium enclosure, I will let you know the result when test pcb's come to me and when all get asembled!
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I see--I didn't catch the volume control via PS. Yeah, the chip I posted would not fit that requirement. Cool project BTW.
Look for LMG5200 ! Easy to design full bridge : ) I made one board with LMG3411R050 https://www.diyaudio.com/community/threads/ct7302pl.357501/post-7355946 but got some problems with iso supply so I decided to stop that temporary, need to remove UVP protection to be able to use volume control based on power supply, and to fix problem with iso supply (MAX17687), tried almost everything to fix with no luch, iso supply simply not work right, it need probably bigger capacitors at primary. Next design will be definitelly better with discrete iso push pull and LMG5200, it will be full bridge instead of half bridge as I done with LMG3411R050. Right now mini DDPD is the starting point, it sound better than anything I had in my home, the huge dynamic non comparable to anything I heard, the importance right now is to finish mini ddpd and start working on ddpd frontend with two ct7302, ct7601 and Ti DSP,, all parts, pcb and things is in my home, already designed, and it wait soldering, when all done right I will start working on Gan based ddpd, probably complete project with enclosure.
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If anyone needs this is an old HB design that was never finished, analog, require some mods e.g. post filter FB, I won't work on it, but I hope someone will find it interesting. I not like digital sound trough analoogye, opamps and etc, it change sound, ddpd is the right way for today digital music since it not have any conversion from analog-digital, digital-analog other than pre speakers LC filter where DA conversion is done, for me it sound only right : )
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One interesting thing is that 1bit DSD mixing is possible https://www.diyaudio.com/community/threads/1bit-dsd-bitstream-mix-possible-yes.402025/ without any modification to the original bitstream, for example direct recording an orcestar in an studio with few DSD microphones and combining that records into one track e.g. 1bit DSD256 will be very promissing for later hearing them on DDPD, I'm believing it will sound brutaly right!
Later I will play around with the Nth order filter to be strictly at 20-30KHz with a steep edge, measurements is not important for me right now but plan is to have good filter at the end of ddpd. Post filter feedback reguire something hmm ultra fast to be able to compare IN-OUT 1bit DSD bitstream & modify IN bitstream on the fly, its now just an imagination : ) My idea is something simple, for example an HV window discrete comparator which do not reguire reference but to have an memory efect which will compare previous sample with new sample so since ddpd are working with 1bit DSD bitstream it might be maybe possible to compare IN bit with post window comparator bit and in the same time manipulate-change IN bits with new value. That part of discrete circuity would be called post filter FB. Hmm maybe possible?
Later I will play around with the Nth order filter to be strictly at 20-30KHz with a steep edge, measurements is not important for me right now but plan is to have good filter at the end of ddpd. Post filter feedback reguire something hmm ultra fast to be able to compare IN-OUT 1bit DSD bitstream & modify IN bitstream on the fly, its now just an imagination : ) My idea is something simple, for example an HV window discrete comparator which do not reguire reference but to have an memory efect which will compare previous sample with new sample so since ddpd are working with 1bit DSD bitstream it might be maybe possible to compare IN bit with post window comparator bit and in the same time manipulate-change IN bits with new value. That part of discrete circuity would be called post filter FB. Hmm maybe possible?
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Forgot one thing, window comparator must be simple with function to simply detect the falling or rising edge of the sine signal on the post filter, in case sine is failing bit 0 is put into memory or vicewersa if sine is rising bit 1 is stored into memory, so we compare bit from memory with IN bit, it not match & IN bit getting modified with new value, it can be done trought an NOR gate or something analog way, but hmm! Every idea is welcome!
I'm started working on DDPD Mini, it's moving! Noticed some bugs but next revision will be perfect : ) In next few days I will work on mcu to programm variable power supply, oled display, volume & standbay function.... What is your opinion, white or black front panel or any other color?
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GaN drivers are very niche, only one voltage supported, a generic low-side MOSFET driver chip is more flexible, though finding a really fast one is the key. Of course you could just use a GaN H-bridge and have lots more power. I've had success playing with EPC9203 half-bridge modules (https://epc-co.com/epc/products/demo-boards/epc9203)