Plexi filtering question

[macula56]

I see that Plexi's use all 50uf ecaps. is this a necessity or just the way they were originally built? I've built several Fender style amps with 2 100uf in series and then all 22uf for the other nodes and they always sounded great. Is there a particular reason that Plexi's have all 50's? I googled it but couldn't really find an explanation. Anybody know why? Thanks as always, JMac.

[sluckey]

Just a guess, but it could be as simple as Jim liked the way the dual 50 cans looked. Maybe he even got a price break on them?

[macula56]

do you notice any difference using smaller values on your plexi builds? i was thinking of building a variation on your dual preamp Marshall. You use 1Meg Log pots for all your volumes and your bass control but the usual Marshall schemos use 1Meg Audio pots. Any particular reason? Thanks, JMac

[macula56]

where's the link drgonzo?

[macula56]

thanks. i will check that out.

[sluckey]

do you notice any difference using smaller values on your plexi builds? i was thinking of building a variation on your dual preamp Marshall. You use 1Meg Log pots for all your volumes and your bass control but the usual Marshall schemos use 1Meg Audio pots. Any particular reason? Thanks, JMac

I don't have any plexi builds. My November amp is a plexi front end into a fixed bias EL84 power amp. That's as close to a plexi as I have. I used 32µF or 33µF simply because that's what the design folks at ax84.com used.

I never actually built the dual Marshall, but if I decide to build it I'll use dual 50µF cans just like the original.

As for the volume pots,,, audio and log (tapers) are considered the same these days.

[macula56]

thanks Sluckey.