Post by Steve Deckert on 07/25/20 at 03:19:45
A good variac is about the only way to soft start your entire amplifier. There are some issues however... Firstly if it cost much under $400 it's going to be made in China and burn up. Secondly, most variacs are designed for technicians and can be turned up too high which would likely blow up your gear. Also, there are live voltages on the binding posts of this model. So lots of ways to fail with this approach, but if you live alone and know what you are doing, it would be great.
The reason we use these is ironically for safety. When a new build is tested for the first time, or an amplifier is in for repair it is always plugged into one of these so we can slowly raise the voltage. If you get to 10 volts and the amp meter starts climbing rapidly, you know you have a short so you turn it back down to zero and find the problem. It's a lot better than blowing fuses and stressing parts.
Steve