ProtoDAC TDA1387 X8 project

[hifinet]

Where did you get the module? Soldering of the caps looks sloppy. Order mine from Ali HuaXinHuiDianZi Store.

I believe the smaller caps are the power supply decoupling caps and are required for stability. The larger caps are connected to pin 7 of the chip, and it is my understanding that they can be removed. It will change the sound quality, but the chip will still function.

[jwchen119]

I tested continuity between 5v and GND and it was positive (beep from multimeter)

Edit:
I managed to remove the x8 module. No continuity on the pcb now between vcc and gnd.

Checking the module, I have continuity between vcc and ground.

Checking the capacitors on the underside, I have continuity on half of them

Looks like we have brought the same module, this one keeps my PI from booting.
5V and GND is indeed shorted(PIN5&28). And the PIN2 and PIN 4 is not conected.
I've ask the seller about the schemetic, but they said they don't have it.
   

[hifinet]

He should replace a defective module.

I have not found a schematic for the modules.

Module pins 2 and 4 should connect to chip pin 1 BCK. Module pin 1 connects to chip pin 2 WS or LRCK. Module pin 3 connects to chip pin 3. Module pin 5 connects to chip pin 4 (ground). Module pin 28 connects to chip pin 5 (Vdd or 5V). The smaller 100nF caps connect across chip pins 4 and 5. The larger 1uF caps connect between chip pin 7 and ground (no module pin connection for chip pin 7, unfortunately). Module pin 6 connects to chip pin 8 (right channel out) and module pin 25 connects to chip pin 6 (left out). All chips are in parallel, except pin 7s which are independent.

[hifinet]

Closest to a schematic. For the TDA1543 X4. Search for 1541tran.jpg .Site bbs.hifidiy.net .

[gperpetuo]

Where did you get the module? Soldering of the caps looks sloppy. Order mine from Ali HuaXinHuiDianZi Store.

I believe the smaller caps are the power supply decoupling caps and are required for stability. The larger caps are connected to pin 7 of the chip, and it is my understanding that they can be removed. It will change the sound quality, but the chip will still function.

I bought mine from "SHS IC Store" for 6.62€. Already asked for refund...

Fortunately I have access to some nice "toys"/tools at work so I could take the module out during lunch time. All caps on my board are the same. Looked at them with microscope at work...

Found HuaXinHuiDianZi Store, same price (6.64€). But had to search quite a bit to find it... From the pictures they have, it's easy to see the difference on the caps size. (their ranking is also quite good). Already bought one not to loose more time. If I have a replacement working, I'll make a second DAC... already have 4 more pcb's, cap's, resistors, etc... 

[hifinet]

That's interesting, because I thought these were all coming out of the same factory. There are many more sellers now, and prices have dropped substantially. One of the largest sellers to enter the market recently is the Lusya Technology Store. No personal experience. I have always bought from the same store. He now packages the modules in individual, static resistant bags, catering to single unit buyers.

[jwchen119]

Where did you get the module? Soldering of the caps looks sloppy. Order mine from Ali HuaXinHuiDianZi Store.

I believe the smaller caps are the power supply decoupling caps and are required for stability. The larger caps are connected to pin 7 of the chip, and it is my understanding that they can be removed. It will change the sound quality, but the chip will still function.

I bought mine from "SHS IC Store" for 6.62€. Already asked for refund...

Fortunately I have access to some nice "toys"/tools at work so I could take the module out during lunch time. All caps on my board are the same. Looked at them with microscope at work...

Found HuaXinHuiDianZi Store, same price (6.64€). But had to search quite a bit to find it... From the pictures they have, it's easy to see the difference on the caps size. (their ranking is also quite good). Already bought one not to loose more time. If I have a replacement working, I'll make a second DAC... already have 4 more pcb's, cap's, resistors, etc... 

I'm contacting the seller for the pin definition of module, I hope someone could come up some idea to modify these modules since I just bought 3...
I think the jump wire between ProtoDAC and 1387x8 module should do the trick, but I have to know the pin definition of this module.
And further more, could help someone who get the incompatible module can still use it on ProtoDAC.

EDIT1:

Just found something maybe useful.
   

EDIT2:

The seller said he cannot and will not contact the PCB layout provider for the PIN definition or the schematic, which is pretty sad news.

[hifinet]

Different boards are now popping up. When I started the project, HuaXinHuiDianZi Store was one of two sellers. He listed quantities in the several hundred. He now lists in lots of 20. There was one other seller who sold in lots of 10. I purchased from him once, but he messed up the order and I never purchased from him again.

All of the modules I have tested (hundreds) have worked in ProtoDAC, except for some rejects with one bad chip based on low output signal voltage.

I have not opened or tested the newest batch that are individually wrapped. I need to do this.

Thank you for bringing this to my attention.

[jwchen119]

The seller sent me a video, which shows pin5 and pin28 is not shorted on PCB.
So what will cause it to shorted after soldered?
And I just found that the pin28 is also shorted with pin14(DGND)

       

[hifinet]

It's not a dead short, but a semiconductor voltage drop? It might vary with the type of meter, but with my DMM it beeps with a semiconductor and then shows voltage drop. With dead short, it beeps and then measures a resistance.

The other question I have with your module is that all the ceramic caps are the same size. Did they just use all 100nF caps to lower cost?

The seller has blank PCBs? I would like to get modules without the pins. That would make it easy to stack modules. I want to try 100R I/V resistors and four paralleled modules. I have removed pins and stacked two modules.

The TDA1387 X4 modules are back. The ones with the 1uF electrolytic pin 7 caps and 100nF film decoupling caps.