The sm7 or sm7b definitely benefit from a preamp with a lot of gain since it's a low output dynamic Mic... There's a great way to get around trying to make up all that gain...Look into the Cloudlifter CL-1, it provides up to +25dB of gain that partners with your preamp in amplifying your mic signal for clean, transparent recordings. Super clean!!! At a price of only $150, it's a must have for anyone.