I used to have a rack with a SWR Grand Prix (1U) preamp, Sampson rack light/conditioner, rack tuner, Alesis 3630 compressor, and Aphex exciter, and a separate rack for the power amp. All totally superfluous but it looked pretty with all the lights on an flashing etc 😂
I still have a smaller rack based setup with the SWR Grand Prix preamp, the SWR Marcus Miller preamp (currently for sale on here), and the SWR Amplite power amp, but it doesnt get a lot of use hence the sale of the MM pre.