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Capacitors for HP filters in tube amps recommendations?

I’ll soon be installing a capacitor on each of the input jacks of two tube power amps, to create passive 1st-order high-pass filters. Cap values are 19.9uF (20uF will do) and 30.33uF (let’s say 30uF). I’ll need two of the former and four of the latter (balanced/XLR input jacks), and I don’t want to spend more on the caps than the amps cost me ;-) .

I’m all ears for nominees. I don’t need or want any flavoring, "just" neutral transparency. The amps are powering fairly transparent loudspeakers (ESL’s, and Magnetic-Planars with Ribbon tweeters), which will pretty well reveal the character of the caps. In spite of that fact, "most-bang-for-the-buck" nominees are of particular interest, not cost-no-object ones. Thanks y’all.

128x128bdp24

Showing 6 responses by erik_squires

erik_squires
15,657 posts
 
Modern film caps are usually spot on in terms of measurements, but you can always order matched pairs.

I've not bought a film cap in ages that wasn't actually within 1%.
erik_squires
15,657 posts
 
I'd do it this way just for the sake of ease of changing things. It's far easier to swap out interconnects than to get into an amp/pre and solder a cap, regardless of the size of the cap. 

However, it's your money and effort, so do it however it feels right to you. :)

Best,
Erik
erik_squires
15,657 posts
 
BDP24 - You know, you can easily make yourself an interconnect cable with a cap in line, no reason to mod your existing pre. :)


But good for you for catching the size problem with those! :) I forgot to mention it.
erik_squires
15,657 posts
 
On the inexpensive, I like Cornel Dubelier a great deal.

If you want to try pricey ... both Audyn (True Copper Max) and the 600V versions of Jansen copper foil caps come in 0.01 values.

Best,

Erik
erik_squires
15,657 posts
 
... and what is the crossover point you are trying to achieve??



erik_squires
15,657 posts
 
Um, I think your cap values are off by a couple of orders of magnitude.

What is the input impedance of the amps??

Erik
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