ProtoDAC TDA1387 X8 project

[radiant_radish]

I returned the DAC for a refund - the seller stated in the eBay refund page that he had fixed the DAC "in a a few minutes". I could ask him what the problem was if you like?

[Tim Curtis]

I returned the DAC for a refund - the seller stated in the eBay refund page that he had fixed the DAC "in a a few minutes". I could ask him what the problem was if you like?

Yes that could be helpful to others :-)

[smokey_mountain]

I would like to know how to fix the static for sure, if the seller would explain how he fixed in no time. I love the ProtoDAC sound, such a musical DAC with Jentzen caps it is almost magical, but boy that static hurts my ears. I have studied that DAC schematic and looks like foil resistors cannot be causing static. I know that output caps are not either since I took Jentzens out and replaced with Audiophile stock ones.

Huge thank you to Tim and Mark for making music sound so good. moOde software combined with ProtoDAC rocks it out of the park with great UX and sound.

[radiant_radish]

The seller stated that he just swapped the DAC chips - I guess it's a bit of a lottery with these chips. I've had a TeraDAC HAT based on the 8xTDA1387 for over a year now and it's been fine (though not as good as the Proto). I'm still on the fence about buying a replacement because of this - if only I was handy with a soldering iron!!

[smokey_mountain]

The seller stated that he just swapped the DAC chips - I guess it's a bit of a lottery with these chips. I've had a TeraDAC HAT based on the 8xTDA1387 for over a year now and it's been fine (though not as good as the Proto). I'm still on the fence about buying a replacement because of this - if only I was handy with a soldering iron!!

Thank you! Swapping DAC chips requires equipment that is not cheap as they are flow-soldered onto the carrier board. Plus it is a skill. The gentleman who sells the kits here, he is super helpful and keen to help but yes, it is ultimately about having the right tools and ROI on those tools. I do OK soldering job but flow-replace TDA1387 onto a board, will be a difficult task for me as you need to be able to id which 1387 failed. Even buying premade x8 modules on the AliExpress one needs to test them before installing onto ProtoDAC. There are instructions on how to build a rig to test these modules when they come from China but you need to build that rig.
Even unsoldering module from the ProtoDAC PCB is not trivial, it can be done but does require skill, no doubt. 

ProtoDAC sounds very analog to my ears (I know, I know "analog", "musical" ... folks will call my blufff on these statements but), that is why I have built two of them, my son enjoys his immensely in his system. Mine failed after about 6 months of daily use. Now I need to purchase and build another kit to replace this failed one.

[radiant_radish]

My Proto had the x8 module (with "replacement for TDA1541" stamped on it) and only lasted a week! I agree the sound texture is very nice - even with the TeraDAC I was surprised by how nice it sounded (relative to it's price) but as a non-DIY person I don't think it's the best route for me.

[Apache]

I just received the kit from https://www.ebay.com/itm/285868435602 and it works perfect.

This is my first step on this , with kali reclocker , one trafo 2 x 7Vca and 2 x 5Vcc regulators ( one for Pi and Kali and one for DAC ). 

Moode works perfectly.

For the next step I want to add few buttons and here I will probably need some help. I am new on Moode

[smokey_mountain]

I just received the kit from https://www.ebay.com/itm/285868435602 and it works perfect.

This is my first step on this , with kali reclocker , one trafo 2 x 7Vca and 2 x 5Vcc regulators ( one for Pi and Kali and one for DAC ). 

Moode works perfectly.

For the next step I want to add few buttons and here I will probably need some help. I am new on Moode

What are these white output caps? I have tried the Soviet caps and the Z-caps. I preferred the sound of the Z-caps, surprisingly, Audiophilers were actually great sounding with the music that I played. Z-caps were very expensive in comparison to Audiophilers.

[Apache]

Jantzen Audio Compact MKT 10uF / 160Vdc

[hifinet]

If there is static only in one channel, the problem is not the three I2S resistors. First try to resolder the left channel I/V resistor (connected to pin 25 of the module) connection to ground. The ground pad connects to the ground plane, and the pad needs a lot of heat to properly flow the solder to the pad. Add some flux to remove any corrosion from the lead or pad. Heatsink the I/V resistor lead on the topside of the PCB to protect it.

If this does not help, it is possible that a single chip in the module is bad. Sometimes cold spray can temporarily help, and that can be useful to identify the bad chip. Sometimes pressing on each chip with the eraser end of a pencil can identify the bad chip. There could be a bad solder joint there. Also, as a test, use a ground probe and connect to each of the chip pin 7. This should reduce the volume level of that chip. If the static decreases, you found the bad chip.

Due to tariffs, the Chinese market for the modules has unfortunately dried up. Hopefully, this will change in the upcoming months.