Hi Chris sadly, it's the never-ending obsessive holy grail quest for quality tone at civilised low volumes..

.. any valve amps master volume and power valves need to be pushed hard at 10
to hit the speaker cone into creamy compression & crunch..
while maintaining control from the guitar vol knob.

Even a 5 watt amp [or my 3w & 1w amps] walloping into an inefficent 20w speaker will still be a bit too loud
for practice in a terraced town house.. or stage volume for smaller venues..
but with help of an in-line / power-soak attenuator at least more practicable & acceptable..

[my ideal guitar tone is vintage early 70's]