Build thread - building the Subbu DAC V3 SE

[voxxonline]

ok thx

 

[atupi]

Also 50mhz clock is a bit tricky to solder and my advice is to put a very thin layer of solder on pcb pads and xo pads and take de surplus with solder wick. This helps in my opinion.
I think the 50mhz xo is the most temp sensitive part from this Dacia.

 

[bcmbob]

Agreeing with Ivan, there is an opportunity for a centralized info and tips collection point that already exists. The first post in a thread remains editable at all times. I'm not sure if I as the first poster have that access alone, or if JP as the originator can also change things. In any event, let me suggest that as a great place/method to publish some basics.

I'd be more than happy to do the collecting and posting, and would encourage builders to include photos with their comments. There is normally a best practices path in most DIY projects and IMHO, lots of unnecessary mistakes could be avoided with some up front information.

As an example - a silkscreen image or schematic that includes all practical test probe locations would be great. I'm sure there are others.

What says the group??

 

[Audio Zen]

That would be great Bob. Perfect timing because I am about to start testing and those test points would come in handy

I just fired up my power supply and getting 4.94v. Connected my dac to power supply and no smoke so far.

Any suggestions for next steps?

 

[atupi]

Follow the schematic and check if every reg in doing his job, also you can check for dc on output if you want. Afetr that give it a listen and enjoy it.

 

[bcmbob]

Checking the voltage at the spots on pic L3, L4, L5, L6. That's as far as Iv'e gone.

 

[atupi]

Bob, in your pic C7 should be reversed. It is a silkscreen mistake.

 

[bcmbob]

I Did. That was an early shot before the mistake was discovered. I'll post the corrected in that first post group. Doesn't hurt to point it out again though. Thanks.

 

[Audio Zen]

Thx guys. I am getting 3.3v where you say I should have 0.79v....mmm everything else is correct.


C7...I need to switch around. Could that be it?

 

[bcmbob]

I removed that photo. Misleading without reading the text. I'll replace it as said in post #168

 

[Audio Zen]

I switched C7 around but still getting 3.3V

edit...k I see you updated your pic to show 3.3v

So I should be good to hookup....hope...

 

[bcmbob]

Another view -

We are now at the limit of my knowledge and experience .

 

[Audio Zen]

Observed the following during build when i had some problems with overheated oscillator: if the oscillator is not working on pin 11 of ES9023 you will measure a voltage <1v. When oscillator is working you measure on pin 11 around 3.2-3.3V.

Atupi, do you know which one is pin 11 if the dot on chip is left side?

I am not getting any music from output.

edit...I found a better datasheet....google

K so I am getting 3.3V on pin 11. Any suggestions?

 

[GaryB]

Any suggestions?

Post some pictures so we can check for any wiring errors.

----Gary

 

[Audio Zen]

I checked Q2 and noticed that I did not have one of the pads connected. I removed Q2 and put it on its side and then added left over leads to the 2 farthest pads so all 4 are connected. Fired it up and found that L3 is only 0.8V. I checked C19 and I have about 4.5V but C5 only has 1.7V.

I reseated C5 but still get 1.7V.

 

[GaryB]

I checked Q2 and noticed that I did not have one of the pads connected. I removed Q2 and put it on its side and then added left over leads to the 2 farthest pads so all 4 are connected. Fired it up and found that L3 is only 0.8V. I checked C19 and I have about 4.5V but C5 only has 1.7V.

I reseated C5 but still get 1.7V.

Neville,
What part did you buy for Q2? It doesn't look like the right part.
---Gary

 

[Audio Zen]

I ordered from Mouser : XPO-HC736R-50
Here is their datasheet.

 

[Audio Zen]

Well, I had it incorrectly positioned. I have all the correct voltages now but still no sound. I suspect I might have fried Q2 because the amount of time I fiddled with it and had an iron to it. I do have 3.3V on pin 11 of ess9023 chip so maybe there is still hope.

 

[Audio Zen]

All 3 sounding good Atupi ?

Bob, you need C34 + C35 or C34 + C32 and in both cases you can use a SMD cap at the underside of the PCB. Always use C34 ! Try to have a total sum of capacitance larger than 2 µF but not larger than 22 µF.

We did this because MAL128 caps are different in footprint and some of you wanted pads for different caps...Vneg pin is a sensitive one. You will have better results when using larger capacitance than the data sheet value of 1 µF.

Apart from C34 + (C35 or C32) are there any other cap options? I thought I saw somebody asking about C31 vs another cap?

 

[bcmbob]

That was probably me. C32 and C31 have a common pad - one on top - one on bottom. I'm still not clear on that arrangement/implementation. Is C31 always installed or is it included in the optional approaches? Though some photos of successful V2 builds with mods in that area have been posted, there still hasn't been a working V3 stock build posted (with photos) that I'm aware of.