BUILD THREAD - A New Take on the Classic Pass Labs D1 with an ESS Dac

[opc]

I'm just uploading a youtube video showing how to go about soldering the SMD parts. I'll post a link when the upload is complete.

Sometimes a moving picture is worth 10,000,000 words.

Cheers,
Owen

[qusp]

good work mate, I dont have a video camera unfortunately, I thought of doing that the other day

[opc]

Hi Davide

I posted a quick clip which shows the soldering process for one of the diodes in the kit. It's pretty poor quality (taken with a digital camera), but at least it should address some of the confusion.

For the record, that tip was too large for SMD, and the solder was far too large. Usually you want much finer solder, and a smaller (but not needle point) tip.

If you have some solder wick, the you can go back and clean up any joint that has a little too much solder on it. with a tip that large, and solder that thick, it's easy to get too much solder on the joint.

hope this helps.

YouTube - MVI_5833.AVI

Cheers,
Owen

[qusp]

but those diodes are easy, I think the main issues they are having are with the 1210 size caps as the pads are only a tiny bit larger than the cap. I noted this issue myself in an early post, but didnt really have any problem after I sorted technique on the first one. you do have to place it dead center though, which could prove to be the most difficult thing for people without such steady hands

[opc]

The purpose of the video was purely to demonstrate the basic technique we've both been describing in words. When Davide mentioned he had parts sticking to his iron, and not being able to hold solder, tweezers and the iron at the same time, I figured people were not really getting the basic concept.

The finer points of how to remove the iron from the joint, how much solder to apply, and exactly how to apply the iron to the part/pad are all things people will need to master on their own. I'm not sure you'd get much from a video when it comes to that stuff. You just have to do it.

Granted the caps are a little harder, but its the exact same thing, just adjust the technique a little bit. In the case of the 1210 caps, you end up heating the parts a little more than usual, but as with you, once I did one or two parts, I got the hang of it.

As for the steady hands, people are on their own with that one. All the videos in the world won't help with that! Take a deep breath, relax for a second, and go for it.

Cheers,
Owen

[qusp]

fair call mate, wasnt really criticizing, just being picky as is my way, you know that even though that seems to be the tradition around here. regardless I think its great, reckon it'll help either way.

main issue with the caps is probably the ground plane and not tinning the ground pad first, also not being afraid to crank the heat right up, as long as you move confidently and quickly all is well. as you say its something that just has to come with practice

[Nikon1975]

So, it looks like my SMD component are done. Just some tips from my side for people who do SMD for the first time:

1) Start with the diodes of the rectifiers, they are the easiest component.

2) Resistors follow: they are very small, but the pads are big enough to allow good contact between the iron and the component.

3) Zener: I did the track side before the ground plane. This allowed me to place the component in order to leave as much space as possible on the ground plane pad to push the iron on it and have good contace.

4) Capacitors are the most difficult, as there is not much space to put the iron and to heat the track. I did, but here I'm not sure of the results. I did this as first components, and I think it was a mistake.

I used 400 C as temperature and for few pads on the ground plane I had to rise it a bit.

Owen, think for the video, it was very useful. Few questions:

1) Is the headphone amp the same level of complexity ?
2) Does it matter what kind of tin do you use ? I saw you have a super duper one.

I'll post some pictures soon.

Thanks,

Davide

[richluvsound]

Hi Gents ,

this is my first SMD project . Could someone recommend a brand of flux to buy here in the UK please ?

Cheers , Rich

[qusp]

I like cardas organic flux, if you only use a little bit it doesnt need cleaning, well it doesnt need cleaning at all, but if you use too much its a bit ugly.

Davide: as far as solder, I go for either cardas tri or quad eutectic, although perhaps this is a bit large gauge for SMD beginners, best thin gauge flux core wire solder IMO is Kester 331 which has a water soluable flux core, but the flux like most is corrosive if you dont clean it, for no clean Kester there is Kester 245 for leaded or Kester 275 for no clean all the Kester products mentioned here are available in Sn63Pb37or Sn96.5Ag3.0Cu0.5, I prefer the latter; for audiophile peace of mind more than anything. I always go for quad or tri-eutectic alloys if I can and that one is the best lead free mix I know is tin silver and copper. it is available as small as 0.25mm which is what I use. brands like mundorf are IMO more for cables and I dont even like it for that due to high heat needed to get it to flow properly and it will melt the insulation of some wires before it wets properly. so yeah one of those, cardas and the kester are flux core, but I recommend getting some flux as well to use for stubborn joints; I actually use it on every joint out of habit.

hope that helps

[qusp]

I realy do recommend tinning the ground pad first of all the joints not just soldering it first, but tinning it first before there is a component anywhere near it, then reflow the solder on the pad and move the part in then hold till it cools. cant get more room to solder it than not having a part there at all