Thanks for the reply.
Both my mic and the cable have the standard 3-pin XLR connection. I'm not sure how you see "2 wires/pins" in the photo above; I am not sure where you see that.
I bought the adapter cable at Fry's Electronics. It is probably not high quality.
Can you tell me how I can figure out if I my mic needs phantom power and if my amp provides it?
The amp is small (12-watt) and looks like it is from the 70s (PRIME amplification):
I'll post mic model/specs when I get home.Another hint: when I tried using a PC microphone with a 3.5mm - 1/4" adapter, I was barely getting any signal from the mic through the amp. The only time it worked at all is when I put my mouth directly on the mic and made a low-pitched humming/breathing vibration noise and I could still barely hear it.