Can you really HEAR mkt caps?

Michael · 2006-02-03T18:51:54+00:00

I know they look good on test equipment but can you really hear the difference in an audio circuit with these MKT capacitors?I have an analog devices op amp and I've put a couple of 10UF electrolytics back to back in a non polarized arrangement on the output and it sounds awful good to my ears.I ordered some to compare but I'm a cynic by nature.

Feb 03, 2006 23 Replies

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Michael 20 years ago

So, the amount of capacitance also depends on the amplitude of the signal?

UF value is more than just the reactance/frequency relationship?

I've always just used a high value electrolytic (100UF or more) to get as much audio through as I can and (it always sounded better...more low end).

I was about to ask why I see values like 3.3uf or 4.7uf on the output of audio opamps (especially these MKT caps).

How does the level of signal influence the value of capacitance? (not the working voltage but the value)

I saw the back to back thing in Walter Jung's "How to pick a capacitor"....hence my using it. (Not a series back to back....I'm putting them in parallel to create a non-polarized combination).

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Pooh Bear 20 years ago

Actually, very slightly for an electrolytic, but its an indirect relationship.

Biggest uF is best for electrolytics.

Simply doesn't matter for film caps. Film caps simply suffer from big cost/uF.

It's *not just about low-end*. Bigger electrlytics mean smaller signal volts across the cap. This means less distortion as a result of non-linearity.

Film caps don't have the non-linearity issue but aren't available in practical sizes for good low-impedance coupling.

I've never seen that but I'm an audio pro and don't bother with audiophool nonsense.

If you like to use $5 caps suit yourself !

I simply avoid using caps where they aren't needed. Often they aren't essential. DC coupling is often preferable.

If the signal across an electrolytic exceeds ~ 100 mV they start to distort.

Obviously film caps don't distort ( no relevant mechanism ) but they aren't available easily in large uF values.

Tha sounds intruiging.

I've never tested them 'back-to-back' !

BTW - the THD introduced by electrolytics is small typically and only at low frequencies ( maybe 0.01% ) but still worth avoiding.

Graham

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Michael 20 years ago

Thanks Graham, I'll print out this for reference.

Yeah, I'm no audiophool myself....it's just amazing the amount of debate (and contradiction) you can run across.

Hell, it's about what you hear......and don't laugh but I'll take some harmonic distortion and a tad of "soft compression" when I listen to music.....and in blind tests, I imagine alot of others would too.

That Walter Jung article is on the web at his website.

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