Do you start fine tuning the system with cables or tubes ?

audphile1, yes, tube rolling for the purpose of fine tuning can easily become expensive. But you can sell the tubes that you don't need, at a loss perhaps, it depends. " Cable rolling" can be even more expensive, so..

@audphile1 

"re-tubing with stock tubes is maintenance."

Never once said I rolled or re-tubed anything. You'd do better not to embellish.

@faustuss you said earlier that you haven’t rolled tubes. And you indicated you prefer to keep it true to what the designer intended. 
 

That’s what I responded to. I think this conversation is over. 

My 2 cents worth is to look at the volume potentiometer .

If you have a cheap alps get a TKD. Cheap compared to tubes and expensive cables. If there is room get a pair of Duelund cast caps.

I have done these 2 mods with outstanding success.