Beginner needs some soldering help (I'm trying to build a CMOY amp)

What are you building the circuit on? If it is a PCB, then there should be a specific spot for each component, and traces connenct the various components appropriately. However, more likely for a cmoy is that you are building it on perfboard. Generally on perfboard there are columns of holes connected together on the back of the board. For example in your drawing, for ever column on the board rows 1-4 might be connected, then rows 5-8, etc. If this is the case then the leads of the led and resistor that are supposed to be connected simply have to go into a hole within this connected column. The leads do not have to be physically connected, just electrically. You didn't attach the circuit diagram, but if that is indeed a power led it is likely that the positive lead is connected to the positive rail of the cmoy, the negative lead is connected to one lead of the resistor, and the other lead of the resistor is connected to ground/negative rail of the cmoy. 

 

Hopefully this helps, and if you have more questions I would attach the circuit diagram as well. 

First off, I don't know which guide you're using, but you should take a look at tangent's guide.

http://tangentsoft.net/audio/cmoy-tutorial/assy.html
All should be answered there





Also, it doesn't matter if you solder it to the end of the positive or negative...
The resistor will restrict the flow of electricity just the same no matter which end it's on.

The bottom of your perfboard, which I am assuming you are using will at many times have several holes connected together. Usually 2, 3, or 4 on a smaller board. You put each lead of the component in a different hole but because the copper traces on the bottom are connected to eachother, you have effectively soldered one lead to the other.

If you don't have holes connected together, you can use jumper wires on the bottom of the board. If you have any long stretches, make sure to use a shielded wire to avoid shorting anything out, if you are trying to connect two holes next to each other, just use a short piece of unshielded and it will be fine.

And yes, use Tangent's guide.

Edited by balderon - 3/4/11 at 5:05pm

It looks like either your soldering iron is not hot enough or you are not properly heating the wires/leads before you try to flow solder onto them. If you have a soldering iron with adjustable temperature I usually use somewhere in the 700-750 degree F range. When you go to solder something, place the wire through the hold in the perf board. Secure it somehow- I usually bend the lead over slightly so it stays in place. You are not dripping solder onto the lead, your trying to melt it directly on the lead. To do this, hold your iron against the lead for a few seconds before you attempt to add any solder. At this point touch the solder to the lead and it should melt right on. If the solder is not melting easily onto the components then things are not hot enough or the metal is corroded. So you can try turning the temperature up on the iron, trying to heat the component for a longer time, although you don't want to go too long or you might damage the component, or applying some flux to get rid of corrosion. The solder should also not flow off of the metal traces on the back of the perf board if properly applied. 

 

For the stray solder, if you take the iron with a bare tip and just kind of poke at it you should be able to gather it up onto the tip, you can then wipe it onto your sponge. If you don't have a damp sponge to wipe your iron on I strongly suggest getting one. Alternatively, you can purchase some solder wick which is basically tightly braided very thin wires. Press the wick up against the solder you want to remove, then press down with your iron. As the solder melts it will be drawn up into the wick. You should still have a sponge though.

 

I suggest going on youtube and watching a few soldering tutorials so you can get an idea of proper technique, and then of course practice makes perfect...