Wanted: Pair of Copper Foil Capacitors

Caveat emptor, Caveat venditor
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#16 Re: Wanted: Pair of Copper Foil Capacitors

Post by IslandPink »

ps. what I will say in addition to that, is that conclusions about caps need to be assessed also in terms of where they are in a system - eg. what signal level and drive current. I would not use a paper-in-oil cap in a phono amp or at line-level, but in a power amp with dozens of volts drive and 20-30ma from a driver, I have compared polyprop with copper and tin foil against the Jensen PIO coppers, and found the Jensens to be the best , most natural midrange, and not lacking HF detail. At smaller signal levels they are sonic death, HF sounds rolled-off and dull, the polyprops are much better.
"Once you find out ... the Circumstances ; then you can go out"
User avatar
Ray P
No idea why I do this anymore
Posts: 6294
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

#17 Re: Wanted: Pair of Copper Foil Capacitors

Post by Ray P »

IslandPink wrote: Mon Oct 28, 2019 10:29 pm Copper foil caps are typically only of a value suitable for coupling caps, so they won't change the operating point of the driver or the output valve.
The value will affect the bass roll-off point, that needs to be borne in mind when listening.
Yes, I assumed they would be used for coupling and the operating point I had in mind was the bass roll off frequency - changing that frequency sounds harmless (but 0,47uF is half 1.0uF so its low frequency point will be twice the frequency) but the fact is that with the different brands/values you will be making two changes so when you make a comparison and name a favourite will that rating be because of the cap construction or the roll-off frequency. That's all I'm observing.
Sorry, I couldn't resist!
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8867
Joined: Mon May 21, 2007 9:42 pm

#18 Re: Wanted: Pair of Copper Foil Capacitors

Post by Paul Barker »

I saw that Ray, totally agree, test tells little except I like that one! Reason clouded by non conformity. Fine, tester be honest with yourself. No one needs impressing with endless discussions around what affected that sound. Find what you like about the three and select what you want, ignore the reason and don’t waste finger presses on a touch screen convincing anyone else. I’ve wasted enough finger presses on this subject already, I’ll go back into Hibernation !
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Nick
Site Admin
Posts: 15707
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#19 Re: Wanted: Pair of Copper Foil Capacitors

Post by Nick »

Reporting findings is just fine. Its up to the reader to decide how to use that information. This is a forum for folk to chat not a peer reviewed journal.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
JohnG
Old Hand
Posts: 418
Joined: Sat Mar 25, 2017 10:59 am

#20 Re: Wanted: Pair of Copper Foil Capacitors

Post by JohnG »

To put it in perspective from my end, seeing as my reference to having three different 'uf' value cap's kicked in a extended discussion.
I thank IslandPink for informing on his experiences with Copper vs Poly's and the other explanations offered on what I might expect to hear in relation to Bass Roll Off from the differing 'uf' values.
I have not got much experience with such comparisons, or even with Copper Cap's I would imagine, even though I would feel quite confident there are a few devices I have auditioned that have them in the circuit.
I was offered a description of my options on Cap's and the trials I would be supported with taking part in to assess the effects.
In my mind a bit like a tube roll with a few Cap's, the fact a individual skilled in soldering is offering their time to assist in the experience, I would be a fool to turn down the opportunity to gather a few thoughts on the outcome.
I am a wasting my time ? well it will be a social meet with a agenda, so that can only be good for the spirit.
Am I wasting my money ? I've spent more on a Shite Take Away, with no resale value, and ended up in a Land Fill Site.
Am I going to discuss my findings ? yeah why not.
Am I going to visit Huddersfield with the end product, to share a audition with a few like minded types, when Dave's venue is back in action, and the invites are sent out? You bet.
The fun is still in HiFi for me, so I'll keep sharing the joy.
steve s
Shed dweller
Posts: 2829
Joined: Wed May 30, 2007 6:19 pm
Location: east yorks

#21 Re: Wanted: Pair of Copper Foil Capacitors

Post by steve s »

It will be good to hear about your findings John. I still rate Jensen copper foil caps for interstage decoupling. I treated myself to a pair of 3.3uf about 5 years ago, i have not tried them yet... but I still have a cunning plan for them !
Interesting what you say about polyprops and low signals.
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
JohnG
Old Hand
Posts: 418
Joined: Sat Mar 25, 2017 10:59 am

#22 Re: Wanted: Pair of Copper Foil Capacitors

Post by JohnG »

Thank you Steve for your interest.
I will let you know how I perceived the variants performances.
I like the guidance offered as to the effects on the Bass.
Post Reply