Got a '68 SF Champ: Pics and Questions Inside

[Commodore 64***]

Your opinion is good enough for me. I will grab some 2.2uf and 4.7uF electrolytics. As long as I'm in there, should I replace the film caps? I'm looking at the schematic and I can't read some of the numbers. Folks mention Mallory 150s a lot, but there's a bunch of different ones and I don't know which to order.

[tunghaichuan***]

Your opinion is good enough for me. I will grab some 2.2uf and 4.7uF electrolytics. As long as I'm in there, should I replace the film caps? I'm looking at the schematic and I can't read some of the numbers. Folks mention Mallory 150s a lot, but there's a bunch of different ones and I don't know which to order.

Don't take my word on it, try it for yourself and see if you like it. I was only making a suggestion based on my personal experiences.

Film caps don't dry out like electrolytics do, so you don't have to change them. If you want to, there are three in the tone stack 250pF, a .1uF, and a .047uF, these are usually rated at 600v or better. The 250uF cap is usually ceramic or silver mica.There is another decoupling cap between the second 12AX7 stage and the 6V6 power tube. It is a .022uF cap. I forget what the stock rating is, but I usually use 600v rated parts.

It's been a while since I looked into caps, but there are a few types: polypropylene, polyester, ceramic, silver mica. From my experience, Malory caps are slightly brighter than Orange Drop types, but I doubt I could pick them out in a double blind test.

You should be able to find Malory or Orange Drop type caps in .1uF, .047uF and .022uF values. As I stated before, the 250pF (220pf) is usually ceramic or silver mica.