Ok, so because they didn't use a bipolar supply, they had to create a different voltage source to operate the op-amp. In the box I'm creating, I don't need that because I'm using the +- 15 V supplies to give the op-amp it's full range.
From what I've read, when using coupling caps, they can, as you mentioned, cause low frequency drop off. The way to reduce that is by using a larger capacitor. What are the drawbacks of using a higher cap in that situation?
The ClearCom stuff is strange to me, because they are using standard XLR cables to pass all of that stuff!
What are the advantages of using an analog switch over a relay? In the talent boxes, I'm using 2 relays, one to open the insert tip/ring to mute the mic audio, and then a second to route the tip to the talkback output and open the tip/ring on the main out. Does it make more sense to use an analog switch in that situation? Why or why not?
Do you have any experience with Arduino?
Thanks again Lotus. I appreciate every bit of advice you've given me, and I'm so glad there are people like you in these forums!