BTDT.
Orchestra had an off-peak night; also due to underfunding my mike preamps were based on old PA can transformers. Displeased Dean could not fix the orchestra, so ordered me to spend what it took to improve the recordings.
I got two of basically the $10 mike preamp (but discrete input devices) in a big rack box with 4-band EQ, limiter, and a Vacuum Tube. Lots of knobs and switches. Big bucks by our standards.
I quickly proved the two limiters could not be stereo-linked as good as a limiter I already have, so that was switched-out. Also the EQ, since with two new AKG 414s I would not presume to question the spectrum on the way to the wax. The tube stage did not have a OFF switch, but I have a soldering iron and know which end to hold. I did do extended trials with/without the tube stage, with a conducting student by my side who had no idea what was in the box, and we agreed the tube made no difference on soft passages but large complex passages were more muddled than sweetened. (Would be different for single source such as a soloist.)
So two $450 boxes with about $20 of stuff actually in the path.
Everybody who saw it loved the sound. (If they hadn't seen the "New!" equipment they didn't notice.)