Just finished putting this Protodac using Philips tda1387 multibit dac chips 8x parellel. Its quite a simple yet seriously one of the best dacs Ive heard ever, no kidding. Im powering it with a 5v supply. I seperated the RPI3 from the dac and ran umpers form the GPIO to the proper pins on the Protodac. I then realized I could possibly utilize the better clocks that my Digi2 Pro board has and feed the i2s form that to the Protodac.I found this Mini thin ITX case that I thought would be perfect and matches my XTZ Edge A2-300 amp as well. Im toying with further improvements as money allows. I wanted to get a reclocker board like the Kali however NONE ANYWHERE nor used. IANS of CANADA is nice but pricey. I wonder if Im able to upgrade the clocks on the Hifiberry Digi2 pro hat. Any know.https://imgur.com/BW4JV09
The Hifiberry Digi 2 Pro HAT already has 2 separate clocks to decouple it from the clock of the Rpi3 and if I’m not mistaken the chip they use also has built-in jitter correction.
So to what extent will you expect improving the clocks will actually significantly improve the sound? You’re working a bit towards the so-called high-end trap of diminishing returns: the improvements that significantly improve the sound have already been made and now you’re just spending increasingly huge amounts of money to get at best single, but more likely tenths or even hundreds of a percent in improvements.
Don’t get me wrong, I’m not trying to discourage you from experimenting, I’m only warning you that you might not get the results you expect to get even after having spent a huge amount of money.
I found the Chassis on Ebay 20 bux shipped! All Aluminum. THe back plate with the I/0 shield I removed and used a back plate to another piece of equipment in my graveyard I painted it to match the case. I wired up some good quality RCA’s as well as a DC barrel jack for power. is acrtually a thin micro ITX case that I’m using. On the inside I took the PROTODAC HAT that I originally made I then wired up some shielded signal cables from under the Hat PCB from the signal + - and added the shielding from cable to negative of RCA on back panel. . So I also used the Hifi DIgi2 Pro for their better clocks and ran jumpers from PI to Digi2 pro and from there to the Protodac. Its not my best work in the inside however this DAC is one of the best I e ever heard and i had ZERO expectations originally.
This is before ading the Digi2 into the mix. Caps were removed off board as they were too high for this case. I have since moved them to a better area and cleaned all that up. Had to use 3 270 ohm resistors in series to tame down that LED in front and it was all i had at time. Not shown here. Ill get some better pictures when shes done.oh and Im powering it all for now with a Linear Supply.
@Gaspar_74 if you want to further improve the I2S (clocking) on your build you might want to check the Kali Reclocker from Allo. Back in the day it made a world of difference. But I am not sure it’s still in production.
Otherwise @iancanada could for sure recommend one of his little marvels
Hi. Yes I have been on the hunt for one for a long time now. Allo has been out commission a while now and no one Carrie’s them. None on used market either. Hence why for now using the digi. There is some boards by Ian of Canada but more than I’m willing spend on a board at moment. The protodac I built from a kit that a guy from Moode audio forum provided. I had seen some reviews on YouTube by a guy in follow and decided to try it. Blew me away and I’ve had much more expensive higher end dacs.
I have seen it and looks to be decent, it has a upgraded clock too. My protdac has less parts and its one best dacs Ive heard. if your not up toputzing around and not feeling adventurous Ive read some folks who took that bpard step further modifying it.
the black PCB is a custom version of Amanero, with cutomn clocks a special firmware that does reclocking too, besided the USB-I2S conversion. Amanero is a USB to I2S bridge, taking care of providing a clean digital input to the TDA1387.
the red PCB is a carrier board for Amanero o for Raspberry Pi (in the picture it’s coupled with Amanero)
the TDA1387 are powered by a linear regulator, providing 5.75V for obtaining a higher analog output, up to 1.3V RMS (with 5.0V the output is 2V RMS)
then every TDA1387 has dedicated Tantalium + Ceramic decoupling capacitors, and dedicated Tantalium + ceramic capacitors for the Vref pin.
