Build thread - building the Subbu DAC V3 SE

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#661
seemtorecall said:
Thanks Bob. Can anyone of you electronic wizard scan a couple of pics for me and possibly catch any obvious mistake if there is any? That would be a great help. First smd solder project, learned a lot... Patience most of all 🙂
Click to expand...

Step 1 - load the pictures properly. I've reloaded them for you in this post.

Step 2 - take a look at U5. Some of the pins look like they might be shorted.

Step 3 - hook up the +5v power supply and see if the regulators are providing the correct voltages.

Step 4 - hook up a source and see if sound comes out.
----Gary
 

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Last edited:
#665
seemtorecall said:
Thanks Bob. Can anyone of you electronic wizard scan a couple of pics for me and possibly catch any obvious mistake if there is any? That would be a great help. First smd solder project, learned a lot... Patience most of all 🙂

Is there a way to check if it's working properly without a source?

C31 on the underside of the board is unpopulated.

Thanks a lot for the help

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An externally hosted image should be here but it was not working when we last tested it.

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An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
Click to expand...

Hi Seemtorecall,
Please double check datasheets on the Sal-rpm caps (c22 & c35). I believe the band marks negative side. I too bought the korben gb parts and c31 was missing. However I'm getting good results with just c34 populated. Cheers.
 
#669
I'll second all the remarks above... once you think it is complete just hook it up to the power supply and measure the voltages.
You can work your way down from the regulators down to the IC's... I had a bit of trouble around the WM8804 until I carefully reflowed a couple pins.
Once you have verified that all voltages are within ballpark you can connect it to play some music.

Btw. To my eyes that's a fine soldering job!
 
#670
Stixx said:
I'll second all the remarks above... once you think it is complete just hook it up to the power supply and measure the voltages.
You can work your way down from the regulators down to the IC's... I had a bit of trouble around the WM8804 until I carefully reflowed a couple pins.
Once you have verified that all voltages are within ballpark you can connect it to play some music.

Btw. To my eyes that's a fine soldering job!
Click to expand...

Thanks Stixx!, I think it wen't okay for a first smd experience, I'll follow that procedure and check the voltages when the last issues are corrected.
 
#671
Let me just add again that opening the package for small SMD parts directly over the PCB helps eliminate much of the tweezers hazard. If you have to flip it put a small amount of liquid/paste flux on the tweezer tips and use minimal pressure keeping everything down on the board.

I use a dental pic to orient and slide the piece into position. As suggested earlier, the target pads should be fluxed prior to placing the part.
 
#672
bcmbob said:
Let me just add again that opening the package for small SMD parts directly over the PCB helps eliminate much of the tweezers hazard. If you have to flip it put a small amount of liquid/paste flux on the tweezer tips and use minimal pressure keeping everything down on the board.

I use a dental pic to orient and slide the piece into position. As suggested earlier, the target pads should be fluxed prior to placing the part.
Click to expand...

Thanks for the tip bob, yeah I changed tactics after my tweezers shot that capacitor into the unknown, learning by doing I guess :/
 
#673
bcmbob said:
Let me just add again that opening the package for small SMD parts directly over the PCB helps eliminate much of the tweezers hazard. If you have to flip it put a small amount of liquid/paste flux on the tweezer tips and use minimal pressure keeping everything down on the board.

I use a dental pic to orient and slide the piece into position. As suggested earlier, the target pads should be fluxed prior to placing the part.
Click to expand...

I open my small parts into a small plastic bowl and then pick them out with good quality tweezers designed for SMD work - never lost a part yet.
Anti-Magnetic Precision Tweezers - Jaycar Electronics
 
#676
bcmbob said:
The operative word being "yet" :magnify: 😀

I read somewhere lately that placing the PCB inside a shallow cardboard box helps to restrict the flight path.😉
Click to expand...

lol - perhaps one day I may agree with your fear of flying SMD parts, but until that day comes, I'm just sharing my thus far effective experience.

I think it depends a lot on the quality of the tweezers. The ones I linked to work work very well - they line up perfectly and don't try to cross over at all. I have other sets that I am certain would eject an SMD part as quickly as I could pick up a tiny part.

or perhaps it's just the operator 😛
 
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