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My σ22 Build Thread

PostPosted: January 30th, 2016, 11:52 pm
by sv511
I will be posting as I build my σ22. I may end up moving this to my electronics blog.

I ordered a kit of parts from GlassJarAudio. The parts arrived yesterday. Sort of. They sat in the local delivery office for a day or two until the tax bill showed up at my house.

P1030473.jpg

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 1:53 am
by sv511
Ready to begin stuffing the board:

Ready To Begin.jpg

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 1:58 am
by sv511
RN55D's installed. One of the reasons I ordered the kit from Jeff was for the resistors. I can get RN55's from RS but they are expensive and often out of stock.

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 2:03 am
by Rolos
I ordered the majority of my parts from RS and like you said the RN55 can often be out of stock.
I actually used a few RN60's.
Good luck with your build and watch the ground planes they suck a LOT of heat.

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 10:11 am
by sv511
Yes, I noticed that about the ground planes. For ground planes, I swap to second Weller TCP-S handle that I have set up for heavier tasks. Even that was not enough for one of the CRDs. I could not get solder to flow.

The board may be contaminated. I forgot to clean it before I started. I tried a few things including using a flux pen and $ilver solder with no luck. In the end, I jumpered it to the adjacent ground pad. That worked and I stopped there.

I want to test the CRD before continuing. After that I'm going to clean the PCB with some isopropyl. I have some wipes but need to find them.

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 10:48 am
by Rolos
I cleaned my board before I started (isop) and cranked the temp right up and still had trouble.

Anyone have any tips for that? Ti?

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 2:00 pm
by amb
I just set my Hakko 936 soldering station's heat up high for the ground plane pads. Chisel-shaped iron tip. I use normal 63/37 solder, nothing fancy. The technique is to heat the pad first with the iron tip for a few seconds first, apply solder, let the solder flow and then withdraw both.

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 2:21 pm
by DEFL
I heat the board with hair dryer before soldering parts connected to ground plane.
Also, the best result is acheved if I solder these parts to ground plane with Hakko 808 desoldering gun (without pressing sucking trigger). Just add flux to the board, then a litle bit of solder on the Hakko nozzle. Place the nozzle with melted solder over the component lead (cut it to desired length beforehand). The result is very good, solder flows easily. The joint looks like made by industrial wave soldering machine.

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 2:46 pm
by sv511
I'm using a Weller TCP-S with a 700F chisel tip for the ground plane. Usually works fine. My mistake was not cleaning the board first. I'm going to buy new tips too. I changed to new ones but one had a Fry's price tags on it. I must have bought that sometime before 2001. Last time I lived within driving distance of a Fry's.

Re: My σ22 Build Thread

PostPosted: January 31st, 2016, 11:26 pm
by sv511
Rolos wrote:I ordered the majority of my parts from RS and like you said the RN55 can often be out of stock.
I actually used a few RN60's.


RS are expensive. A typical RN55D is 7p or £3.50 for 50. The same part from Mouser's UK website is 4.6p for or £1.95 for 50. With a minimum order of £33 Mouser will pay shipping, import duty and customs brokerage.

On Mouser's US Website that resistor is 90 cents for 50.