This is a quick run down of setting up your mic and mic pre to properly work with your interface to get the highest quality and best recording. I'm posting this because I see so many problems with this.
If you are using Sonar, Cubase, Nuendo, Reaper or FL Studio to record vocals first go here and download PSP vintage meter. There is even a AU version for mac.
Free Download 1.1.0 LVLMeter 1.1 Stereo VU meter (FREE) LVLMeter is a VU meter plugin for VST, AU and RTAS hosts on Mac and Windows. Stereo; Vintage VU-meters. PSP VintageMeter is a free vu meter VST, Audio Unit, RTAS, DirectX plugin developed by PSPaudioware. Compatible OS(s): Windows, macOS. PSP VintageMeter provides professional VU and PPM metering for mono and stereo tracks. All parameters like integration times and reference levels are widely adjustable to make this free plug-in suitable for any application.
http://www.pspaudioware.com/plugins/vmeter.html
If you are using ProTools then you can use the stock BF Meter Bridge.
Now load up your recording software and create a new audio track to record to. Make sure the gain on your mic pre is turned all the way down. (Remember that if you are using an external mic pre that the output needs to go to line in of the audio interface and not the mic input.)
Psp Vintage Meter
Next make sure that the fader for your channel for recording vocals is at 0db. Now load the PSP Vintage Meter in the first slot. (BF Meter Bridge if using ProTools). Now click on the PSP logo on the plug-in to view the back. Make sure you change the 0vu refer level to -18dbFS. Now click the label to view the front again and make sure that the meter is on VU with the switch in the middle.Psp Vintage Meter
Psp Vintage Meter
Next make sure that the fader for your channel for recording vocals is at 0db. Now load the PSP Vintage Meter in the first slot. (BF Meter Bridge if using ProTools). Now click on the PSP logo on the plug-in to view the back. Make sure you change the 0vu refer level to -18dbFS. Now click the label to view the front again and make sure that the meter is on VU with the switch in the middle.Psp Vintage Meter
(for protools make sure the meter is set with the -18db button pressed in and the switch on peak)
Psp Vintage Meter Mac
Now while doing a mic check raise the gain knob of the mic pre until the PSP vintage meter reads close to 0db but never over. (BF Meter Bridge for ProTools) Leave it there for your vocal recording. If you change vocalist adjust the gain on the mic pre until you get the same signal in the meter. Enjoy clean vocals. If using a compressor make sure it's bypassed for this tutorial.