Now I am getting ready to restore a pair of MK-IIIs (then finally will do PAS-3). This pair of MK-IIIs is brothers from different mothers - one is much earlier issue than the other - one uses 6550s, the other KT-88s. They are all original, but they look totally different - tubes, capacitors, etc.
Here is a list (and questions) for restoration:
1). Multi-section capacitors.
a). Question 1 - Is there a big difference between German Authenticap and American CE Cap? Authenticap is significantly more expensive for the same values.
b). Question 2 - values. Do I go with original 30/20/20/20? Or upgraded CE Cap 40/20/20/20? Or some people go like ST-70 with 80/40/30/20?
c). Question 3 - I also see Dynakitparts selling selling 30/20/20/20, but they don't mention who the manufacturer is. Same price is Authenticap.
2). 1N 4007 Diode to replace Selenium rectifier.
a). Question - do I need to change the resistor value between the diode and the pot? Or it will get compensated by adjusting the pot resistance?
3). 11-Ohm bias resistors - do these need to be replaced?
4). 2 x electrolytic capacitors 50uF - replace with modern 50uf @ 250V ?
5). Replace power switches (one is stuck in On position), power cords, input and output connectors.