5E3 power supply question

[Randall]

I see some builders using 20uF 500v for two of the filter caps, but sticking with 16uF for the pre filter cap. In a word, why?

[soundguruman]

As time goes on, the caps increase in uF, and decrease in size, they also get cheaper basically..
The larger one has less sag and the smaller one has more sag.
But, availability wise, 20 and 22 uF is becoming easier to get than 16...standard available values change over time.
Sound wise, the difference may be hard to tell apart. There's not a remarkable difference.
The logic behind using 16 may be going for more sag, and making the sound more retro...but
the tube manufacturer may be recommending 16uF max for the rectifier filter cap. Yes, there really is such a specification.
Back in those days, when those specs were written, 16uF may have been a pretty big expensive capacitor.

[Bruce / Mission Amps]

I see some builders using 20uF 500v for two of the filter caps, but sticking with 16uF for the pre filter cap. In a word, why?

Because they don't know any better and think the 16uF caps in the preamp stage will sound more vintage... in my opinion, it's 99% BS.
The vintage 16uf cap's specs were all over the place anyhow. +80% to - 20%.
14-15 years ago, those "still good sounding" vintage 5E3s, had good filter caps in them that actually measured closer to 20uF anyhow.

[loudthud]

The originals from my "5E3" are marked 16MF 450 W.V.D.C. 525 V.S.P. The B+ will go slightly over 450V between turn on and when the 6V6s warmup so the 500V rating gives you a little safety margin.

[Randall]

Bruce, interesting. What do you put in your amps?

[Bruce / Mission Amps]

I let my customer pick them... I stock the Sprague 16uF-475v caps but I don't use them.
Up until a year or two ago I was using the F&T 22uF-500v caps but I've started using these less expensive imports from
TAD... also 22uF-500v.
They work every bit as good as the Sprague 16uF-475v or 20uF-500v caps.
I tried the less expensive Xicon 22uF-450v axial caps and they worked great too.

[soundguruman]

I let my customer pick them... I stock the Sprague 16uF-475v caps but I don't use them.
Up until a year or two ago I was using the F&T 22uF-500v caps but I've started using these less expensive imports from
TAD... also 22uF-500v.
They work every bit as good as the Sprague 16uF-475v or 20uF-500v caps.
I tried the less expensive Xicon 22uF-450v axial caps and they worked great too.

I automatically change to F&T now. I am really happy with the sound of the amps I have put them in, and the customers make lots of good comments.
I think the amps sound better with those installed. Just subjective, of course.
When I compare them to Illinois Capacitor, I hear a major improvement with the F&Ts. A whole new sound I think, way more hi-fi sounding.
I would be using Black Gate too, have had plenty of requests.

[Randall]

I always just feel better with Sprague and Mercury Mag, does that make me a brand name dinosaur?

[Justin Thomas]

Brand Name Dinosaur?

Maybe, maybe not. If you try other less expensive things and there's a difference, cool. No difference, cool too. Personally, I like quality, but I also know advertising is very expensive! I am happy to aim for the middle of the road with my amp & guitar parts. I don't like it, I try something else. If I do like something, I tend to stick with it til they give me a reason not to. I like Mallory caps cuz they fit better than ODs. I like CTS pots cuz they seem a bit more substantial. But I have no problem w. Alpha, and sometimes they're the only ones who've got what's needed. I like GHS strings cuz I don't break them - apparently I'm the only person who doesn't break them. Other brands are fine for other people. I've recently switched to F&T from Sprague for filter caps. Absolutely NO PROBLEM w. Sprague, but NO PROBLEM with F&T either. I put F&Ts in my Bassman and love them. And they're about half the price of Spragues. It's the first cap job it ever had, and it's very quiet now. So I go with the cheaper, because most of the caps I've been replacing recently are strictly a repair&resell thing. If the customer wants one or the other, they're right, unless we're talking $50 a piece or something... then I might talk about it first. I don't think loyalty to a brand you like makes you a dinosaur. But you should be able to say WHY you like or dislike a brand, IMHO.

Justin