Can an audio interface's gain control mute the input source?

Question

I have a Focusrite Scarlett 2i2 USB audio interface, and a Rode Nt1 Kit Mic.

Up until today, I thought turning the gain controls on the audio interface all the way down would mute the mic, but today I found out that I was wrong. It does not mute it, but make it very low.

Is this normal behavior? Or is there something wrong with my interface/mic?

Excuse me if this sounds too simple :-).

Answer 1

Many people confuse two similar controls:

1. GAIN control adjusts the amount of amplification in the first stage of the microphone preamp. It is used to "normalize" the amount of signal coming from various kinds of microphones. Some mics are very sensitive and need lower gain, and some are less sensitive and need higher gain. Gain controls typically do NOT go "all the way to zero" because that is not their function.
2. MIX/LEVEL control adjusts the amount of the channel that goes into the mix. That control always does "all the way to zero" for cases where you don't need that channel in the mix.

The controls on the front of the Scarlett 2i2 are GAIN controls, NOT mix/level controls. They do not reduce the signal "all the way to zero". That is normal operation for most mic preamps.

Answer 2

To directly answer your question: yes, many gain attenuators can still pass signal even at it's lowest setting.

Focusrite interfaces work with their 'MixControl' software which will actually allow you to mute the input (This is useful for their low latency input monitoring feature).

Answer 3

I had another scarlett interface. I also had issues with this but after unplugging the usb and input it it resolved itself. Ensure the monitoring switch is set to mono (if the 2i2 has one).

Make sure you download the latest beta drivers/software too.