A compressor designed to provide greater musical control for tracking and mastering.

https://www.amazon.com/ART-Pro-VLA-Channel-Vactrol-based-Compressor/dp/B0012MIVW4/ref=sr_1_1_sspa?crid=3MUIQYQ8QNYSY&dchild=1&keywords=art+pro+vla+ii+tube+compressor&qid=1587946102&sprefix=ART+pro+vla%2Caps%2C435&sr=8-1-spons&psc=1&smid=AZH80ONF88EC1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyQ1VUVUkyNENEWDZVJmVuY3J5cHRlZElkPUEwNjYyOTE0MlNKUDc2QTJSR0ZZOSZlbmNyeXB0ZWRBZElkPUEwODEwMzc3MTFGUEU2SUlBV0RFNCZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

From Jimmy Sage: The compressor is absolutely necessary for recording vocals, drums or horns in order to keep the recording level even. This will help again with recording the jazz band CD as well as any student recordings that involve those instruments.