The orange caps should work fine for the input caps (not to be confused with the electrolytics in the power supply, which are 220uf or higher). Even if the orange caps were shorted, the amp would still work.
DC offset: take your DMM set for DC volts, and connect the black lead to the virtual ground (anywhere on the two center rows of the board or a resistor lead going there, etc.). Take the red lead and put it on the R output. Then the left output. This will give you your right and left DC offset. Should be in millivolts (0.00x volts). 0 is great, anything under about 100 millivolts is OK, under 10 is preferred.
Some common newbie mistakes from Tangent's really good tutorial:
1) Electrolytic caps in backwards: when looking at the board as in the view provided in Tangent's board layout, the left electrolytic should have its positive pointing toward the top of the board. The right electrolytic should have its positive pointing down.
2) The "M" jumper: This must connect all 3 sets of double pads. This ties the feedback loop together (R4 and R5, I believe) as well as connecting the output.
3) Double check your resistor values! Use a meter, and pay attention to the K ohms and 0s.
4) R5: make sure you either have a small resistor (47 ohms, less than 100 ohms) or a jumper here.
5) Crappy solder joint, bridging: Look the board over carefully with magnification.
6) Double check the assembly without the opamp in. To do this, hook your meter up with the black lead on virtual ground. Take the red lead, and measuring ohms, check all pins in the opamp socket. The power pins (4 and 8) won't tell you much since you will be charging the electrolytic caps up... it may look like a dead short briefly, then work its way toward infinite resistance. This is normal. The other pins should correspond to the feedback and input resistors. For example, pin 5 is the input for one channel. You should be seeing 100K ohms here. Have the schematic handy, and if the value you are measuring doesn't seem right, fix it. Also check from pin to pin to verify there are no shorts. You will see some resistance between certain pins.
Build the amp itself first and get it working before you put a pot in, etc. Get a pack of jumper clips (with the mini-alligator clips) at Radio Shack, and use these to connect the input and outputs to the amp. I think the bag Ratshack sells has 10 of them which is enough. RS #278-1156 or 278-1157. Don't get any that are 2 short (like 1", you want ones about a foot long). You'll need 3 each for the input and output, and another 2 to connect the battery. Once you get it working this way, you can start wiring the jacks, pot, etc. one at a time, so it makes it easier to troubleshoot.
Have fun!
