This year I had a bit refreshed my old DAC, I / V conversion was changed from passive to ground grid, tubes are the same 6S4P, all CCS now have double FET instead of lower DN2540 in cascade and for all digital circuits except for PCM1702 voltage regulators are now ADP7118. High voltage power is a copy of the power supply from ARC LS25MKII.
Otherwise DAC is an old school CS8414-PMD100-2xPCM1702.
Otherwise DAC is an old school CS8414-PMD100-2xPCM1702.
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My piCorePlayer (Allo based)
I put together a piCorePlayer using a Hammond chassis. It has an official Raspberry Pi touchscreen and uses an Allo isolator between the Pi and the Allo Boss DAC. It also has LiPo batteries to power the isolator and DAC. The small board in the middle is a custom board I designed to host the +5 volt linear regulated supply and a charging circuit for the LiPos.
The display controller is underneath the batteries and is flopped down to a horizontal mounting position.
When the player is quiescent, the batteries are placed in parallel for charging and when active, in series for powering the isolator and DAC. The switching is done by 3 relays controlled by a GPIO pin on the Pi. When powering the DAC, the batteries are completely floating and therefore the DAC is galvanically isolated from the Pi power supply and ground.
The setup is currently running piCorePlayer 3.5 and LMS. It is driving a passive preamp which is connected to a McCormack DNA 0.5 and Martin Logan Aerius i's. It sounds very clean, particularly playing 24-bit FLACs and is dead silent between tracks. Having played with various DAC setups, I'm pretty happy with the battery solution.
I should mention that the physical design was inspired by Pascal Hibon, who posted some of his builds over in the Slimdevices forum.
Cheers
Whit
I put together a piCorePlayer using a Hammond chassis. It has an official Raspberry Pi touchscreen and uses an Allo isolator between the Pi and the Allo Boss DAC. It also has LiPo batteries to power the isolator and DAC. The small board in the middle is a custom board I designed to host the +5 volt linear regulated supply and a charging circuit for the LiPos.
The display controller is underneath the batteries and is flopped down to a horizontal mounting position.
When the player is quiescent, the batteries are placed in parallel for charging and when active, in series for powering the isolator and DAC. The switching is done by 3 relays controlled by a GPIO pin on the Pi. When powering the DAC, the batteries are completely floating and therefore the DAC is galvanically isolated from the Pi power supply and ground.
The setup is currently running piCorePlayer 3.5 and LMS. It is driving a passive preamp which is connected to a McCormack DNA 0.5 and Martin Logan Aerius i's. It sounds very clean, particularly playing 24-bit FLACs and is dead silent between tracks. Having played with various DAC setups, I'm pretty happy with the battery solution.
I should mention that the physical design was inspired by Pascal Hibon, who posted some of his builds over in the Slimdevices forum.
Cheers
Whit
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Thanks! I regard this as a work in progress - sort of a learning experience. So far, I am pretty happy with the sound an usability of piCorePlayer on this hardware.
I plan to build other DACs with (possibly) better sound in the future.
Cheers
Whit
I like what you did with the Vu-Meters
I would like to see a video on how smooth the actually work? I have those on my Aurender and is sooo jerky, the might as well have left it away…. 
DIY DAC
Hi ,
Just wish to share my DIY discrete 24 bit R2R DAC. I'm building another one with 18 or 20 bit because of matching resistors are virtually impossible for 24bit, but it sounds great with resistors I matched using 6-1/2 digit multimeter.
a simple video here,
YouTube
Hi ,
Just wish to share my DIY discrete 24 bit R2R DAC. I'm building another one with 18 or 20 bit because of matching resistors are virtually impossible for 24bit, but it sounds great with resistors I matched using 6-1/2 digit multimeter.
a simple video here,
YouTube
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CS4398DAC
I ordered an CS4398DAC card from China. Replaced to good quality parts in Powersupply stage. Audio grade capacitors and plenty of power. I wanted to replase the output op-amp stage with transformer stage. Replaced with Lundahl 1690 1:1 transformer. Im really happy with the result and fits my tube rigg really well. Really better sound than my Rega DAC.
I ordered an CS4398DAC card from China. Replaced to good quality parts in Powersupply stage. Audio grade capacitors and plenty of power. I wanted to replase the output op-amp stage with transformer stage. Replaced with Lundahl 1690 1:1 transformer. Im really happy with the result and fits my tube rigg really well. Really better sound than my Rega DAC.
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You really did it your way and it's great that you've been rewarded.
Quality parts not only worth soundwise but will also extend the longevity of your dac, nice move.
Hi all, Received a message and inform that the image are gone, sorry.I can't see edit post function so I re-attach the Image again.
Youtube video : YouTube
May I ask if you have this project public somewhere?! Im thinking about a 'tube dac' project lately.
(pointers to other cool tubedacs would be much appreciated too of course)
Thanks
https://www.diyaudio.com/forums/digital-line-level/166807-dac-gallery-24.html#post5065812
Linear Audio | your tech audio resource
https://linearaudio.net/sites/linearaudio.net/files/ThevalveDAC_PCB_FPGA_files for web posting.zip
https://linearaudio.net/sites/linearaudio.net/files/additionaldatavalveDACversion2p1.zip
I've been publishing in Croatian audio forums for a long time.
This version is far more advanced than the ones from that time, but I did not publish any scheme or project. This would be a new output stage. It was designed for current DAC.
