ProtoDAC TDA1387 X8 project

[Apache]

This is my second ProtoDac using Raspberry Pi 3B and some component provided by the seller and is working great ( a little slower than the first one using Raspberry PI 4). It is mostly used for testing buttons ; at this moment I test voume control , play and next command.

If someone can help me with command for "previous" function and if it is possible I want to have a button to activate/deactivate one grafic EQ ( like Lo and High boost )

Thank you!

[BeTaller]

Hello everyone,

I've been using Volumio and a Chinese DAC hat on a raspberry Pi and decided to switch to Moode and build myself a Protodac. I just finished building my 1387 module test board and seem to have run into an issue or I just may be overlooking something. Anyway, I've plugged the test board into my Raspberry Pi and booted up Moode Audio. The problem I'm having is I can't play the test wav file because the only output devices available in Moode are HDMI. Nothing is connected to the HDMI ports so the file won't play. I selected Protodac as the named IS2 device, however, Protodac is not available as an output device. Any ideas?
Thanks


   

[Tim Curtis]

Hello everyone,

I've been using Volumio and a Chinese DAC hat on a raspberry Pi and decided to switch to Moode and build myself a Protodac. I just finished building my 1387 module test board and seem to have run into an issue or I just may be overlooking something. Anyway, I've plugged the test board into my Raspberry Pi and booted up Moode Audio. The problem I'm having is I can't play the test wav file because the only output devices available in Moode are HDMI. Nothing is connected to the HDMI ports so the file won't play. I selected Protodac as the named IS2 device, however, Protodac is not available as an output device. Any ideas?
Thanks

Is your ProtoDAC build fully complete?

Swap your Chinese DAC in and verify the Stereo Test file plays correctly. If it does it would suggest the issue is in the ProtoDAC build.

[BeTaller]

I didn't buy a complete kit. The shipping was to expensive to Chile. I am sourcing what I can from Aliexpress and bought 3 of the 1387 modules hoping to get a good one. I built a test board as described by hifinet on the first page of this thread. As it turns out, the first 2 modules are DOA and moode wouldn't recognize the Protodac as an output device. Therefore, the test file would not play. The third time was the charm thou and I could successfully play the test wave file.

[Lolkapies]

Check the soldering for GPIO and TDA1387; the 1387 may be damaged. I've never encountered any problems after soldering it correctly according to the design.

[Lolkapies]

Let me show off a bit — here’s the expanded Protodac version: RPi + KALI + TDA1387 with its own 5V power supply, passive I/V stage with its own ±12V power. It sounds amazing! I encourage everyone to keep developing the project!

[DRONE7]

Interesting addition, passive I/V...do you have a schematic for that ?

Your Kali and Pi on one supply, Protodac on another, and passive I/V on a third ?

[hifinet]

Let me show off a bit — here’s the expanded Protodac version: RPi + KALI + TDA1387 with its own 5V power supply, passive I/V stage with its own ±12V power. It sounds amazing! I encourage everyone to keep developing the project!

It looks like passive I/V (metal foil resistors) with a discrete, active gain stage. Is that correct?

If so, that is similar to my current setup. 100R metal foil passive I/V resistors followed by a 15dB gain preamp. Yes, it's a definite improvement over 420R I/V resistors.

[kookedtweeter]

Ive had my kit built for a while now and I am satisfied with how it sounds. 
I am wondering if anyone else has noticed a very faint pulse from thiers tho?
 
I noticed it when i had audio paused but my amp volume was up.
The woofers had a pattern every second or so that would repeat and looked like a 1-2hz pulse. I connected the protodac to a scope and seen about a 30mv wakky pattern.
Its also reproducible with a song that starts very quiet, and you turn up the amp loud, you can see the speakers fluf in and out every second or so.

Its extreamly quiet! Under normal listening, I would have never heard it. The woofer fluf is visible but not audible, but there is an audio portion to this pattern that can be heard when the volume is up with nothing being played.

Anyways, thanks to all for the great sounding dac, and if there is a fix for this, i look forward to it, and if not, no worries. 

Thanks.

[hifinet]

Ive had my kit built for a while now and I am satisfied with how it sounds. 
I am wondering if anyone else has noticed a very faint pulse from thiers tho?
 
I noticed it when i had audio paused but my amp volume was up.
The woofers had a pattern every second or so that would repeat and looked like a 1-2hz pulse. I connected the protodac to a scope and seen about a 30mv wakky pattern.
Its also reproducible with a song that starts very quiet, and you turn up the amp loud, you can see the speakers fluf in and out every second or so.

Its extreamly quiet! Under normal listening, I would have never heard it. The woofer fluf is visible but not audible, but there is an audio portion to this pattern that can be heard when the volume is up with nothing being played.

Anyways, thanks to all for the great sounding dac, and if there is a fix for this, i look forward to it, and if not, no worries. 

Thanks.

Are you using ethernet or WiFi? With some of the prototypes built on perf board, WiFi was picked up. Nothing playing it is a periodic noise. With a file playing there is a more of a continuous,  pulsing noise. The PCB has a ground plane, and I have not heard it with the PCB. There also might be a bad solder joint that could act as a diode, and pick up RF.