Hi, what do you think about this PCB, I just bought two boards and I want to build my ProtoDac myself.
On this PCB there is the possibility to power the DAC independently or via Rpi (jumper) which is cool, but why is there a third capacitor added here for power supply 100nF?
And is it supposed to be an electrolytic capacitor or something else?
09-19-2024, 05:20 PM (This post was last modified: 09-19-2024, 05:28 PM by hifinet.)
The 100nF C5 position is meant for a film cap. Each TDA1387 chip has ceramic 100nF caps mounted close for decoupling and stability included in the module. Some people think the added film cap across the electrolytic caps improves sound quality. It is possible (and easy) to solder a film cap (or two) on the bottom of the ProtoDAC PCB attached directly to the C3/C4 electrolytic caps.
My only critique of the PCB you pictured is the lack of a ground plane on the lower layer (based on the appearance).
It is possible to wire the ProtoDAC PCB for a separate power supply only. Just don't solder GPIO pins 2 and 4 (also pin 1 3.3V since it's not used). It's not a reversible solution like a jumper.
Using the Gerber files supplied here for the ProtoDAC PCB, you can get 5 PCBs for under $5 shipped using JLCPCB (no affiliation).
Hardware: RPi Zero W | Allo Kali | ProtoDAC TDA1387 X8 | PGA2311 | Icepower 500ASP | Harbeth SHL5 Software: Moode 8.3.3 Source: Win 10 NAS
New x8 module arrived today. Everything working now
Now, time for start improving things... Noticed at the beggining quite a bit of background noise. (Going up with volume improved things quite a bit, maybe start working on shielding and Power supply)
Hi, can Allo Isolator be used for ProtoDac? There are quite a few reviews saying it may not work.
My setup is RPI + Allo Kali + ProtoDac, everything works great, Allo Kali is fed by Allo Nirvana which powers RPI and ProtoDac simultaneously. I am considering Allo Isolator to provide clean battery power for Kali and ProtoDac. Nirvana would be for RPI.
Have you tried using Isolator or maybe you recommend similar product IAN Canada? Does it improve sound quality?
09-24-2024, 04:22 PM (This post was last modified: 10-23-2024, 03:47 AM by hifinet.)
Allo Isolator only works with master DACs. ProtoDAC is a slave DAC.
I am sure an isolator will improve sound quality.
I cannot recommend any of the Ian Canada isolator/reclockers, because they use a nonstandard GPIO (3.3V on pins 2 and 4 instead of 5V).
I have found that a single CPU core has lower noise. You can try adding "maxcpus=1" to the end of the line in /boot/firmware/cmdline.txt if your RPi is multicore. Use the command lscpu to verify. It's free and easily reversible.
Hardware: RPi Zero W | Allo Kali | ProtoDAC TDA1387 X8 | PGA2311 | Icepower 500ASP | Harbeth SHL5 Software: Moode 8.3.3 Source: Win 10 NAS
10-02-2024, 01:50 AM (This post was last modified: 10-02-2024, 01:50 AM by tuantek.)
(09-24-2024, 02:57 PM)Lolkapies Wrote: Hi, can Allo Isolator be used for ProtoDac? There are quite a few reviews saying it may not work.
My setup is RPI + Allo Kali + ProtoDac, everything works great, Allo Kali is fed by Allo Nirvana which powers RPI and ProtoDac simultaneously. I am considering Allo Isolator to provide clean battery power for Kali and ProtoDac. Nirvana would be for RPI.
Have you tried using Isolator or maybe you recommend similar product IAN Canada? Does it improve sound quality?
As the same your system, i've tried (Pi2 + Allo Isolator classic with slave mode + Allo Kali I2S reclocker + Protodac) combo. Everything works great until now.
Tube output is based on Lukasz Fikus (founder of Lampizator) published during his DIY era before he started selling tube DAC at prices of a luxury car.
Two 5670 tubes in SRPP configuration, Miflex KPCU oil capacitors as output coupling, CS8414 receiver chip for coaxial and optical input, QCC5125 USB interface, TDA1387 x 8 DAC.
Mesmerizing. Outstanding vocal. Musical. This DAC reproduces low volume harmonics originated in music source which are missing in many other DACs. Wide and deep sound stage. You can listen to it for hours without feeling fatigue.
