Build thread - building the Subbu DAC V3 SE

LoL.... first try... it doesn't work !

Xo crystal ?!No sound, No buzzing, nothing than a perfect silence from the squeezebox which works everydays with 1865 Raindrop Hui Dac!

I didn't understand if the crystal Xo can be checked with voltmeter function ?
 
thanks :

Fox have is hole near r7, that's good but U3 is not good at all...

which pads of the five do i test with U3 to check the voltage ? The fault to XO (burned with soldering ?)?

Do I have to be worried about the dac chip health with this voltage at U3 ?
 
Last edited:
Check post 186 - see picture, you should be getting similar voltages on the 3 legged side (not middle of 3 leg).

My voltages in that area were all out because my Q2 was connected incorrectly, thats why I am saying you need to check orientation of Q2. I think the pin/hole in on top and the letter O I know for sure is at bottom near R7.
 
Last edited:
Not a specialists but, It appears the outside pads at C6 & C14 are on same trace. Did you read there?
 

Attachments

  • Q1.jpg
    Q1.jpg
    51.6 KB · Views: 358
Hi Bob,

i waq talking about Q2.

Is there a problem with Q1 here ? Not a specialist myself, but a crystal like Q1 must have a cap at each pin?! The comon trace between c14 & C16 is ok for my humble knowledge.

Anybody knows a vendor of ldo regs and crystal without minimum expensive order ?

my u4 and maybe my Fox are dead, hope not the DAC chip.

In fact for non specialists, this project would have been needing a method before the beginning, not only screens pcb ! few words like :

First : soldering the regs, the cap and the ldo, populate the psp pcb then check the voltage.
then populate the two chip,

then populate the Fox (this story remember me La Fontaine : The Fox, the cheese and the bird... something like that !).... but carrefully, with the zero please near R7.

Instead of waiting at the end of the assembly thread, i burned some parts ! Not a good student, not understand the patience concept by subbu and JP... bad hobbit ! I have to try to make a ring with my desoldering braid and flux before throw it to the fire ! Bad Bilbo....

but happy, have the last T Monk disc !


?!
 
Last edited:
Well it seems both Q1 and Q2 are becoming areas of concern and are heat related. I believe the best soldering sequence and best temperatures will be established as we proceed. Hang in there. That pre-tinning the pads mentioned earlier may help.
 
Last edited:
BTW you use too much solder.

I've been fighting excess solder all morning. I'm trying to carry a small amount just on the tip but I haven't found the right size/shape yet. I'll be glad to hear your recommendations. I'm using a 1mm solder because that's all I have today - that may be the problem. It may be well worth it to wait and order something thinner.

I think carrying solder on the tip is not a good idea, all the flux it evaporates just before you are reaching the component and pcb and this is the explanation why your solderings are looking not so tidy.

My way is the following: i put a bit of solder to one pad, after that i just reheat that pad to have one end of component soldered and after that i come with the tip of soldering iron to the other side/sides of componenent and in the same time i add the solder.
I just melt the solder in the place, not carrying at all.
Also very important is to clean your tip with wet sponge as often as possible.

Hope it helps.
 
Repeat mode: this is not a project of beginners. It seems we can not stress that too much. This DAC can only be built when you are experienced. It is a simple DAC but it still is SMD.

I know I made some remarks what parts to solder first but even those are not necessary for experienced builders. If somebody unexperienced started to join this project I feel pity as it can be a difficult DAC to solder. It would be better (if you have doubts concerning your skills) to have it soldered by a friend that knows SMD stuff.

A friend of mine has a project for building a jet airplane. I think I will build one as my first airplane project too. I will do so because I can.
 
Last edited:
Tip: Put a lot of flux to tie the wings

Interested by the plane if Dac is embeded.

OFF TOPIC : VIDEO. "Jetman" survole le mont Fuji avec son aile motorisée

JP Plane advertising... a hoter project... RTFM before ! 🙄

No problem JP we knew the risk before, I think i just burn a LDO reg and hope not burned the ESS chip. How not to be else than a beginner if we don't try ? Sure it's not the same with plane ! Did you see Gravity movie when Sandra Bulock try to read the green book to understand the art of landing ?😛

Next movie : "Can my Subbu DAC fly ?" 😉
 
Hey JP, with all due respect - and that's a lot for your knowledge, effort and dedication to this project - our reality is there are surely hundreds of participants in the V3 SE buyers list who don't have the experience you describe. For years I worked for a power company that employed enough electricians and electronic technicians to fill a small stadium. I can't think of one I would consider better capable of completing this project than myself. No doubt even the best of my co-workers would need to hone specific skills for this application. That is not a criticism of you or Subbu or the design - more correctly simple acknowledgement of a rather delicate soldering process.

I feel like I'm part of a small group that could almost be considered "beta builders" of a finalized design. The components of the DAC are very inexpensive which allows for some trial and error that won't break the budget. If we early builders can stub our toes, figure out what happened, collect the information and experience - I believe (and hope) a "best Practices" approach can be established before the bulk of the folks start their builds.

If a selection of "most likely to fry 😉" components is published, duplicates of those could be added to the BOM purchases. Another area that could use stricter definition of soldering temperature safety ranges. Many won't have lab level equipment, but if recommended, good inexpensive adjustable irons are available and might merit a delayed start if it will increase the success potential.

I'm very excited to hear this DAC, but like most am willing to slow down, make a few mistakes (with recovery) and as a result - get a bit closer to the "experienced" builder level you recommend. :up:

Keeping the faith in Michigan.......
 
Last edited:
Well put Bob !!

Jean -Paul and Subbu, I do not hold you personal if I am unable to get this kit working because I know I am new to this and really in it for experience. I am thinking that this is why Jean-Paul has emphasized the level of experience twice and is concerned about any negativity cast on them.

My parts arrive today, will know if its Q1 or Q2 or both or maybe something else????
 
+1

nothing personal, the threads are here in a looping improvement : Deming wheel.

In electronic, like with plane, spaceship, the landing is always a delicate phase : take care twice to the ground : check twice (Houston do you copy ?).

All my regs are good but one : think it's a happy result for a first time smd soldering.🙂 . And do you check my pictures : not so bad with the chips' pins for a first time, no ?

Here, the result would have been better if a simple methodology exist before (check the voltage before soldering the rare and fragile chips and see also tips for iron pen, smd, flux and so on.

(methodology is the logistic word for experience = the checking list is here to substitute to the instinct of experience, which is only for critical situation : landing the plane in Houston river....).
 
Last edited: