1987 vs 1959 Filterng

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TheMagicEight
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1987 vs 1959 Filterng

Post by TheMagicEight » Sun Aug 12, 2012 10:11 pm

I notice the '69 version of the 1987 seems to have 100uF filtering on the plates and screens, whereas the 1959 only has 50uF on plates and screens. I'm wondering what amount of filtering would be equivalent for a 1987. Would it just be 25uF, since there's half the number of output tubes?

Right now, my 1987 build seems a little stiff. I tried halving the filtering to just use one side of each 50-50 can cap, and that is an improvement, but it still seems a little too thin. To those that have experimented, what is your filtering preference? Has anyone compared directly a 1987 and 1959?

Thanks!

SteadyEddie
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Re: 1987 vs 1959 Filterng

Post by SteadyEddie » Sun Aug 12, 2012 11:33 pm

This is what works for me. My amp is a Ceriatone so the layout might be different. The first cap can to the left looking from the back is mains. I use 100uf there. It gives a tighter bass response but it doesn't negatively affect the feel. The next cap is a dual cap for screens and PI. I used a dual 16uf cap there. I have 16uf on the screens but I stuck a 16uf cap parallel to the PI half so I have 32uf total for the PI. I understand you can get a 16/32uf cap can, old hiwatts used them.
Low screens filtering seems to make the biggest difference in having an amp that's more forgiving to play.

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