What does this mean? MKP?

[skyboltone]

"1 Use ’snuffer caps’
Placing 22nF/1600 MKP capacitors across the high voltage diodes (HEXFREDs) reduces the noise on the powersupply by 18dB!!" (a post off some audio page I ran across)

18db is big stuff. I've seen some caps in mouser called snubbers but what does MKP mean?

Thanks in advance
Dan H

[Voodoo_Man]

I've seen some caps in mouser called snubbers but what does MKP mean?

Thanks in advance
Dan H

Metalized and segmented polypropylene film. According to the attached doc.

[David Root]

Interesting stuff, but doesn't look practical for MI amps unless they also come in much smaller packages. Maybe they do?

10kV capability sounds like overkill, but it's not really. If you have a 500VDC rectified output, for example, it can easily have 2kV spikes in it if the rectifier is a conventional silicon bridge, eg Radio Shack stuff.

Soft recovery hexfreds should be much better than that, but they don't totally eliminate spiking.

[Voodoo_Man]

I get the impression from this doc that MKP is just what most refer to as 'Metallized Polypropylene'.

God Bless,
John

[Dai H.]

Forget what all of them are but caps can have codes such as KT(polyester), MKT(metallized polyester), KP(polypropylene), MKP(as mentioned), etc. signifying the type.

[Structo]

So without the caps across the diodes, what would this noise sound like to my ears?
More prevalent at higher gain?

[skyboltone]

So without the caps across the diodes, what would this noise sound like to my ears?
More prevalent at higher gain?

Hiss. And the thing about it is, we used to put little ceramic caps across N4007 types because in the olden days they had much looser tolerances and the caps were supposed to equalize the diodes turn on timing.

That's a quote above. It's not something I've tried but I picked it up on an audio nut page somewhere. Don't even remember now. Might be a thought though on these high gain suckers we're building. Every little bit helps.