If you are going to be building, I would invest in a variac. Its not, without a little experience an absolute replacement,
but it is when properly used, especially if you pre test your power supplies before hooking them up to amp. After you have built a few,
you get to trusting the power supply you built, I still pre test them.
Once proven and hooked up, you can slowly ramp up voltage just like on an old electric train set! Just keep an eye out, an IR thermometer
out and look for anything funny as you ramp up. My wall voltage is about 120, so if all going well take it up to 90 volts and let it set. You will also note when your uotputs are coming on, watch bias, like voltage keep low until full voltage. Then after some warming, bring up bias while adjusting offset.
Having extra fuses, one in each leg will allow you to work one side at the time even though amp is completely wired.
First couple of turn on I do with variac, once stable lower bias a touch, remove variac and plug in wall. power up, let warm fully, adjust up bias to where you want it to be, recheck few times, now just another amp...
You cant meaningfully adjust anything with dim bulb, its just a fail safe that will save amp in event of mistake. Proving power supply first will get you a long way in that respect, then the slow upping of wall voltage while monitoring saves the rest...