hi, let' say i have an analog drum machine connected trough an audio interface, What is the best quality level volume you choose.

 

I would set the drum machine's volume control (if available) to 75%. I would create a new, empty project in my DAW. Set the DAW's output control to -0.1 dB and the input control to minus 8-12 dB headroom. I would then run the drum machine and lower or raise the input control, i.e., the headroom, until I can hear the drum machine comfortably and clearly.

 

I record my drums at -6db

 

A few dB of headroom.

Learn simple gain-staging and you will be fine. It ought to be the first thing one learns.