I mean I’m sorry if I’m too blunt but I feel like this is such a silly question. I really wouldn’t take a record as serious if it was not recorded at the very least through a pre amp and or a compressor. Let anyone here with more experience than me tell you that u don’t need one and can use your interfaces is straight lying to you. A vocal in my eyes should be gained in different stages. Pre amp and the the eventual output level from the compressor. Much less simple than one knob but much more control and variation. You can get a decent pre amp for less than $1000. This shouldn’t even be a question. I think it’s as essential as the microphone. If you want to be taken seriously in this business you would invest in yourself and get the proper equipment. I’m a singer myself and if I booked studio time and the studio didn’t have a pre amp let I would laugh get a refund and leave. The best studios are running all different kinds of channel strips compressors EQ’s let alone a measly little pre amp. In todays digital age where everything sounds colder, you’re going to want at the very least one piece of outboard gear to introduce some kind of warmth to the signal. If you’re curious my main signal chain for vocals is Manley Reference C > Rupert Neve Designs Sheldon’s Channel > CL1B Compressor > El8X Distressor (which I usually have bypassed but I use it occasionally within the chain or I can bypass cl 1b and use distressor instead if need be) > Apollo 8p Quad > iMac. But you see there are songs for SoundCloud and then there are real records. It’s your choice what you want to make.