Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Locrian99 on November 22, 2025, 12:31:43 am
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Hey all,
I'm going to be recapping a friend of mines bassman 100. The 22u power filter caps are all rated at 525v in the original schem. The only options I have been able to find from Amplified parts and tube depot are 600v Spragues at 30$ each to hit or exceed that voltage. Schem shows they will be seeing <450v so I was thinking I'd just use the 500v and should be good. Any reason this isn't a good idea.
https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_100.pdf
Thanks
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All depends on the B+ voltage when the standby switch is off. If its only 470V, then 500V caps will be fine
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550V 22uF F&Ts scoll down to KONEL22 http://askjanfirst.com/eindex.htm
Dunno why US vendors don't get these in :dontknow:
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I've switched over to film caps when possible. Yup they are big, and may not fit the standard cap can, but easily available in 600V versions (or lower, whatever is needed). I haven't had one fail yet (past ten years). My new builds get these for sure. It does take a minute to get your mind wrapped around these caps though!
For Hi-Fi, still have to use the electrolytics due to the size needed for smoothing.
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22u film cap sounds huge
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Sometimes you get more options with different search settings, capacitance, voltage, etc.
What was the standard 50 yrs ago may not be the standard today.
Radial caps might be an option with some tinkering.
Another option might be to use 2 caps in series, as newer caps usually take up less room. You'd have to wire them in a package with some balance resistors.
Or, you can buy once and cry once, and not have to worry again for 50 years.