Capacitor Question

[Musica Bella]

Why not go for silver mica capacitors? Tolerances are as low as 1-2%

I would stay away from silver mica. The tend to be “hard” sounding from my experience.

 

[Carlsbad]

As others have suggested, I think your results are likely to be much better than your theoretical 40% and also much better than their 20% guarantee wrt matching. The difficulties in designing and building a capacitor to an exact number should be the same for both of them if you order them, and they are built, as a pair. So if one is 15% high, then the other one should be 15% high as well.

I would ask Dueland if they agree with this logic, and if +/- 20% works for you so long as they are a matched pair, I'd order them.

Jerry

 

[VinylSavor]

Do you actually need that kind of tolerance? There might be other ways. I personally would first try a version of the filter with readily available caps. Only if that gives the sound results you are looking for go for higher quality caps. Since (I assume) you are building up the filter yourself or have it build up by someone. You could get the caps you are looking for. Then measure them and then adapt by varying the resistor value to get the desired corner frequency. Much simpler than custom ordering the caps in the precision you are looking for.

 

[DasguteOhr]

Why not go for silver mica capacitors? Tolerances are as low as 1-2%

I would stay away from silver mica. The tend to be “hard” sounding from my experience.

How did you use it as a bypass or as the only capacitor in the signal path? I'm asking for a friend.

 

[christensenleif@msn.com]

I tried to custom order 2,700pF and 3,000pF capacitors from Duelund, from its CAST copper line, for a DIY high-pass filter.

Duelund says it cannot guarantee each capacitor any closer than 20% to the actual value requested. In theory I could have two capacitors that are 40% apart in value! I think this is ridiculous.

Who makes a high quality high-end audio capacitor with values of 2,700pF and 3,000pF and some semblance of consistency?

Thank you.

Try to locate some Russian Milspec Precision Teflon caps
I have seen down to at least 5% tolerance

 

[christensenleif@msn.com]

3000pf 5% 200V FT-1 Russian teflon capacitors MILITARY /RHOMBUS NEW QTY-5 | eBay

FT-1 3000pF 5% 200V teflon capacitors. The FT-1 is a high quality teflon capacitors made for military. The conductor is made of aluminum foil and the dielectric is teflon foil, glass sealed in a aluminum body.

www.ebay.com

 

[christensenleif@msn.com]

Here they are from Ukraina
Both values in 5%
They are very good

Btw the link is safe and the Ukrainians are reliable to trade with

Pardon Our Interruption...

 

[Ron Resnick]

How did you use it as a bypass or as the only capacitor in the signal path?

This capacitor will be in the signal path.

 

[Ron Resnick]

Do you actually need that kind of tolerance? There might be other ways. I personally would first try a version of the filter with readily available caps. Only if that gives the sound results you are looking for go for higher quality caps. Since (I assume) you are building up the filter yourself or have it build up by someone. You could get the caps you are looking for. Then measure them and then adapt by varying the resistor value to get the desired corner frequency. Much simpler than custom ordering the caps in the precision you are looking for.

Hello Thomas,

Thank you for your advice.

I understand that methodology, but I don't want unnecessary components in the
signal path.

 

[Ron Resnick]

As others have suggested, I think your results are likely to be much better than your theoretical 40% and also much better than their 20% guarantee wrt matching. The difficulties in designing and building a capacitor to an exact number should be the same for both of them if you order them, and they are built, as a pair. So if one is 15% high, then the other one should be 15% high as well.

I would ask Dueland if they agree with this logic, and if +/- 20% works for you so long as they are a matched pair, I'd order them.

Jerry

Or what about ordering four of the same value and just having them figure out which is the closest matched pair?

 

[VinylSavor]

Hello Thomas,

Thank you for your advice.

I understand that methodology, but I don't want unnecessary components in the
signal path.

I don't understand? You want to introduce some sort of filter. I did not suggest any 'unnecessary components'. Also: You already have many capacitors in the signal path some of them some big ugly electrolytics. Worse : probably several of them in series. So what is the fuss about this particular capacitor? I merely suggested a way to cope with the tolerances

 

[christensenleif@msn.com]

Or what about ordering four of the same value and just having them figure out which is the closest matched pair?

You have a schematic of this filter?

 

[Ron Resnick]

You have a schematic of this filter?

Why do you ask?

 

[Ron Resnick]

I don't understand? You want to introduce some sort of filter. I did not suggest any 'unnecessary components'. Also: You already have many capacitors in the signal path some of them some big ugly electrolytics. Worse : probably several of them in series. So what is the fuss about this particular capacitor? I merely suggested a way to cope with the tolerances

Thank you. I must've misunderstood.

I'm not using a resistor, so I thought adding a resistor would be a new and unnecessary component.

 

[Neil.Antin]

Parts Connexion has Amtrans Capacitor 2700pF 100Vdc AMCH Series Copper Foil Polypropylene https://partsconnexion.com/amtrans-capacitor-2700pf-100vdc-amch-series/; cut sheet https://amtrans.asia/wp-content/uploads/2021/09/021_AMCH_e.pdf, that they will provide matched pairs.

 

[DasguteOhr]

You have a schematic of this filter?

In a tube amp you need only change first couple cappacitor for input tube or add when not there.If I remember correctly the cutoff frequency was 200hz.
47kohms input needs 0.015uf cap ~220hz

 

[christensenleif@msn.com]

Why do you ask?

Because I’ve pointed out a good solution that you seem to ignore and I’d like to see where it’s intended
You seem to have little clue about what you’re about to do imo

 

[VinylSavor]

Thank you. I must've misunderstood.

I'm not using a resistor, so I thought adding a resistor would be a new and unnecessary component.

Ok I (as some others it seems) understood that you want to implement a filter. If so there is a resistor at play. Anyways it would make more sense to first get a better grip at what is the intention before chasing boutique components. There might be a super simple solution to this. And as I pointed out: Why worry so much about this one capacitor if there are many others in your system which are obviously not Duelund and do not seem to bother you

 

[bonzo75]

I understand that methodology, but I don't want unnecessary components in the
signal path.

You have pnoe with Mayer 46 already? lol

 

[Ron Resnick]

Ok I (as some others it seems) understood that you want to implement a filter. If so there is a resistor at play.

In a simple first order high pass filter my understanding is that only a capacitor is needed because the input impedance of the amplifier functions as the resistive load.

Why worry so much about this one capacitor if there are many others in your system which are obviously not Duelund and do not seem to bother you

You are totally correct about this! But you are minimizing audiophilia nervosa: I want any additional components to be fancy, high-quality components.