The combi XLR/jack input connectors, with their gain pot and pad, and Hi-Z switch, plus the insert returns, offer a lot of ways to connect input sources to your Nucleus. The following information should help you decide how best to connect your sound source.
- When the XLR Mic input is used the normal input impedance is 1.5k. Switching to Hi-Z will raise it slightly. This will result in a slight change in frequency response with ribbon mics, but would be very subtle with condensor mics.
- When a jack is inserted the input impedance will be 10k normally (suitable for keyboards) and 1M in Hi-Z (suitable for Guitar or Bass DI).
- If you want to connect an external mic preamp, best practice would be to connect it to the Insert return to have the best gain structure. It could also be connected to the combi Jack 10k but then the pad should be used as well, which will give less favourable noise performance.