FWIW, I used one of these,Did my first "tube-rolling" today with my OG Space Heater.
View attachment 4786953
Swapped out the 12AX7 for a 12AT7.
Results?
Less overall gain, but more useable volume range.
Still adds that "it" factor, so I'm happy.
In stock, at local brick n mortar shop.
Got a second one to try in my HWSH.


