At that point, the tube is presumably warmed up

I did open up the unit to see how easy/difficult tube changes would be, and was impressed by the build quality and design

you buy this preamp, buy a nice ($25 or so) tube from an online tube reseller and put it in for best results

But it reproduces that rich, full, warm tube sound perfectly

I used the stock tube but have not yet tried a better tube

Nice inexpensive tube preamp with phantom power

With many tube-based mic-pre's, it is common to increase gain before accordingly adjust the output level as a means to force the warm, "tube compression" sound, but with this unit, I would recommend the opposite