First, since this'll be in an altoid's tin, can I solder all the "grounds" to the case?
Secondly, would I be able to you a higher ohm resistor for the LED do give me a dimmer light and allow for longer battery life?
No, handling the enclosure won't be a problem. If you hear sounds while touching the case, it's because of some other problem, not because you have a metal box.
If you want a list things to worry about with mint tins, that can be provided:
The main effect the resistance has is that it forces R2 higher, which increases the amp's noise floor. It requires R2 to be 1M+, plus it makes the input more sensitive to induced noise.
All that is minor next to the fact that you're proposing to put in a cheap, scratchy pot. RS pots are not particularly high quality.
I have enough parts that a second one shouldn't be too expensive to make, this is my first and is mostly just for practice but also to demo some pawnshop headphones.
So I have the power section hooked up and am using an old battery, the problem is that going from positive to ground I get .6v and from v- I'm getting -6.7v. I checked the soldering and re-soldered a few places but no dice. Any suggestions?
Can you post pictures?
No? Seriously? As early as 5 years ago you had to try to find a cell phone without a camera. Set it to maximum resolution. I want these pictures so big that they make my (fast) internet connection slow down.
How far along in the build process are you?
Did you follow Tangent's instructions? If not, whose instructions did you follow? Where did you deviate from the given instructions?