Zesto Andros PS-1 Tubes

You shouldn't hear any additional gain from brand to brand. The eletrical parameters should be the same no matter which brand you choose. The sound however does change in terms of tone, extension and imaging, amongst other things.
Pops are you suggesting we build our own tubes? I doubt you meant that, many of us, including me, don't know how to build a component from scratch. The one thing I can modify quickly, without soldering in most cases, is a tube switch. It affects im the sound in very obvious ways in most instances. It is a rare case that stays unaffected by a tube roll. It is easy and rewarding.

Mechans I wasn't serious about building a tube amp, I was simply saying buying a component for 4k and attempting to change the sound from the designers voicing without giving it some time and getting to know it seems strange to me.

I put some UK mullard tubes to replace JJ input tubes and found presentation bigger warmer and more musical.

I did not have additional two for output tubes but will get some more and perhaps some Raytheon and amperex gloves to try.

I have the Orotfon MCA90 cartridge so it's very revealing and fast transients so seems to prefer tubes with fatter midrange

I know have 4 mullard tubes and sounds better still. Might want to try some Amperex or Raytheon. any thoughts?