Try hosting your pic at photobucket.com or somewhere similar.

Wow this is great.  I've been wanting to use one as a preamp (and did for a while) but was told not to because even though its small, it is technically a poweramp chip.  I was told it would do damage to my amp to run it that way.  So did you basically wire it like a little gem and then instead of going to a speaker, it goes to the rest of the amp?  Is the rest of it identical?

Cool, I love the idea as a LM386 as a preamp.  What'd you use for a schematic for that?

Have you double checked your battery is good?  Also, does your battery get hot?  It might be a short.  If you can take pics of your board, we can look at it and give you some more ideas.

Also, one of the biggest mistakes with a fuzzface is putting your transistors in wrong.  Or using NPN trannies instead of PNP. 

In theory, yes you could.  None of us have done it yet (this board is quite new), and so if you want to try it, let us know.  The only thing is, it may not drive the poweramp to full potential, but you can adjust the gain from 22 on the poweramp boards. <- That is in reference to the LM3886 boards a lot of us got from chipamp.com

Yup, I did that to my Dean Markley K-20X and love it.

Yup, sure can.  In fact, thats what those kits are designed for lol.  I'm using a LM1875 stereo amp as my computer speaker amplifier.  Works great  8|

Follow the directions here:

http://singlecoil.com/docs/out.pdf

I have a mono LM3886 actually, it gives 50watts at 8ohms and 68watts at 4ohms.  It's a really loud setup.  And yes you can run half a stereo kit, but instead of buying a stereo kit, it would make more sense to buy a mono kit.  If you want to get one from chipamp.com, just email Brian and he will set you up.  That's how I got mine :-)

Yup, thats exactly how you would use it.  As for the line out, it depends, what do you have for an amp?

An acoustic speaker should work so long as it has the right wattage ratings, but the sound might not be quite "right."  Also with the bass in an electric guitar amp, it should be ok here and there, but some have said that, especially at loud levels, it is a lot of stress on the amp.

The first one you listed I have built, its ok at best for guitar.  A 1/2w little gem is about as loud, and much better quality.

Sounds like you may have it as good as you can get it. I've seen plenty of amps from the factory that have hum like you speak of.  On that same note, if you work at it hard enough, its not impossible to totally get rid of hum from the amp.  However, hum from guitar you may not be able to get rid of without working on the guitar.  Single coils are known for hum, so that could be part of your issue with the guitar if its a SC setup.

It seems the best idea is a small secondary transformer, its easy, cheap and supposedly helps cut out unwanted noise.

Have you looked at this:

http://cordova.asap.um.maine.edu/~raymondj/imagehost/lm1875.pdf ?

In looking at that, there are three grounding points off the power board.  One goes to each ground of the power in section on the amp boards (labeled GND) and the last one goes to chassis ground.  Hope that helps.