The pcb has four layers and therefore it requires much more heat than regular two-layer pcb. Ecpecially the ground connections are heat demanding (pads with a "star"). Use a 50 watts (at least) temperature controlled soldering iron and warm the pad so it really melts and tin flows to the component side. As you can see in my pictures I haven't succeeded to make 100% perfect solder joints and especially hard are the ground connections. If you check the R3, here I should have burned with the soldering iron a lot more. You can warm up the pcb with a hot air gun if you have a weak soldering iron. This will make a lot better result. It's not crucial for the function to have tin through the hole since they are plated.
Besides from these instructions the regulator is pretty easy to build but pay attention how you should mount all polarized parts. See pictures below and also the pdf file. In the pdf file I have made placement pictures with extra clear markings for each part. Print it and have it beside you when you solder.
This design is very easy to build. . You can solder the parts in the order you'll like but it may be practical to start with all low parts such as resistors and then take higher parts.
Start with all low parts except for the output power amp and the opamp. Suitable order can be like this:
If it's a SMD type, start with opamp. It's hard to solder if you have any parts around the opamp. Put tin on any corner pad, like 1, 4, 5 or 8. Place the opamp and adjust so it is sitting straight. The solder the rest of the pads.
Solder all resistors. Use cut off resistorwires as jumpers.
- Opamp if it's a SMD type. It's hard to solder if you have any parts around the opamp.
- Resistors, jumpers
- Zener diodes
- Plastic capacitors
- Transistors, voltage reference. Fat outline = LM431. Thin outline = LM329 or other 2-pin devices.
- Trim pot (if you use it)
- Capacitors, elelctrolytic
- Regulator, power transistor