I've used a number of these inline preamps, but so far I haven't found one that's worth keeping. I've also built a few DIY ones, some of which are really good, but still more often than not I just plug straight in - even with my SM7B's.

In general, if your mic preamp has enough gain and a low enough noise floor, these inline preamps can actually add more noise. For me, I had better results just with my preamps.

However, everyone's situation is different - I'm an electronics technician, and for the most part I use preamps that I custom designed and built (which also have an impedance control). My Focusrite 18i20's preamps are also stellar. However if like most people you're using whatever's in your interface then most likely you'll see some improvement.

Basically what I'm saying is, adding more electronics to the signal chain is not necessarily better.

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