New small, 1.4 by 1.7 inch, PCBs that hold a single rotary switch and allows two transformers to be switched on in a staggered fashion. The three positions are: all transformers off, transformer 1 on and transformer 2 off, and both transformers on. With this setup, you can turn on the heater transformer first, so the tubes are given a chance to heat up, which will create an electron cloud over the cathodes, protecting them from the B+ voltage.
Or you might want to switch on the line-stage amplifier but not the phono preamp, as why wear out the phono stage’s tubes, when you are listening to CDs? The switch uses redundant contacts and offers a 125Vac and 0.6A rating.