Awesome, looking forward to watching this build. Out of interest, where are planning to get your reverb tank?
So I put in the master volume And a switchable attenuator.
Attenuator has 3 levels, -3, -6 and -10. I didn't use his exact design but it's the same idea... And honestly I'm underwhelmed, even -10 is a surprisingly small reduction and I never use the other two.
Master volume on the other hand gives you a massive range and I seldom turn it up above half way, even at the garage days jams. Almost all of the clips I've posted on the group have the master set to less than 20% with kids sleeping in the next room.
That said, the 10% attenuator is an easy mod and does give an extra option if you want to drive those output tubes a little harder. Just remember that those 25W resistors need a heat sink (chassis works well), I completely missed that at first.