Do someone compared these mundorf caps ?

[system7]

I think I made my point quite clearly. Building capacitors out of silver, gold, platinum, unobtainium, diamonds or whatever fancy expensive material you can think of, will not make a significant difference. I'd rather you add something to the debate than nitpick minor points. Sorry.

Your 6% figure confirms that, and the fact that none of the metals are going to tarnish badly when protected in the cap. It is better to use a thicker layer of something more affordable.

Let's recall that 2.2uF MCaps are $5 a pop, supreme $20 and Silver a staggering $60.

I'm learning some interesting things in looking into all this. Some authors suggest that electrolytics are terrible as coupling caps if no polarising voltage is applied. Non-polars may be much better between amplifier stages and in feedback loops. Think I'll try that, since MKPs of 10uF and 100uF are way too big.

[DRONE7]

Well if you really believe that tin and silver are similar conductors....
system7

All a bit bogus for the most part since we know silver (or gold) is not really a better conductor than copper or aluminium or tin.

When...
bulk resistance measured in micro-ohms/centimeter:
Silver 1.59 Best
Copper 1.72
Gold 2.44
Aluminum 2.84
Zinc 5.8
Platinum 10.0
Steel 10.4
Tin 11.5 Worst

When you are making

we know

assertions it does help to actually know.
If nit picking=facts then I plead guilty.

[system7]

OK, here's a summary:

Mundorf MCap: Bargain basement aluminium metallised with DF of 0.0002. $5.

Mundorf MCap ZN: Tin metallised foil with DF of 0.00002. $20.

Mundorf Supreme: Aluminium metallised foil with DF of 0.00002 and aluminium casing. $20.

Mundorf Silver/Oil: Silver metallised foil with DF of 0.00002 and some special casing. $60.

Mundorf Silver/oil/Gold: Silver foil with 1% GOLD added. No idea what they cost.

Mundorf RXF: Encased in some sort of solid box. No idea what they cost.

Interestingly, inductance is a function of the length of the capacitor in these low-inductance windings.

You pay your money and make your choice, I reckon.

[AllenB]

Originally Posted by system7

Some authors suggest that electrolytics are terrible as coupling caps if no polarising voltage is applied. Non-polars may be much better between amplifier stages and in feedback loops

Aside from the obvious that polarised caps are only biased because they need to be, is this simply a matter of tipping some assymetry into the curve? As long as the characteristic is free of odd kinks, could the bias equate to a 'warmth' control?

Originally Posted by system7

Interestingly, inductance is a function of the length of the capacitor in these low-inductance windings.

Considering the way that 4x the intended value is used to create a practical non-inductive capacitor, do you think the small inductance was worth this compromise to eliminate?

[system7]

Originally Posted by AllenB

Aside from the obvious that polarised caps are only biased because they need to be, is this simply a matter of tipping some assymetry into the curve? As long as the characteristic is free of odd kinks, could the bias equate to a 'warmth' control?

Considering the way that 4x the intended value is used to create a practical non-inductive capacitor, do you think the small inductance was worth this compromise to eliminate?

I'd say that polarised electrolytic capacitors work pretty much as advertised. Without a bias, they store charge and are very non-linear. Makes me want to ditch op-amps and go back to single-rail amps and simple transistor designs really! For instance, some of these Class A low-feedback single rail designs that people love use a whopping polar electrolytic 3,300Uf cap on the speaker output. It works very well because it's biased properly.

This allegedly expensive (X4?) low-inductance approach is actually industry standard for big value caps. A good briefing on how it's done here from ILLINOIS CAPACITOR, INC.:
www.lintronicstech.com/index%20pdf/introduction_to_film.pdf

[AllenB]

Originally Posted by system7

This allegedly expensive (X4?) low-inductance approach is actually industry standard for big value caps. A good briefing on how it's done here from ILLINOIS CAPACITOR, INC.:

Ah yes I had a stash of those once that I particularly liked the sound of, no I was referring to this...(taken directly from Mundorfs site)

1. Special induction-free winding technology: Two capacitor windings are interleaved so that their inductances effectively cancel each other out. These two windings are connected in series. This means that it takes two 2µF windings to make a single 1µF MCap-Supreme capacitor - the same amount that it would take to produce a full 4µF of capacity using conventional technology!

Makes me want to ditch op-amps and go back to single-rail amps and simple transistor designs really!

Yes, I used to tweak gear (CD players, tuners etc) by stripping back the final buffer stages, gain stages and anything that called for an electrolytic, when I could, or replace the op-amps and the electros when I couldn't, then finish up with a good cap and a high impedance gain stage, maybe a 6SN7?