top of page

Paper in oil Capacitors
The holy Grail in Audio

Did the microphone industry forgot about them ? 


As any true vintage Gear enthusiast knows, there are a number of topics which, on internet forums, consistently trigger long and arduous debates.  The topic of paper in oil (PIO) capacitors vs. capacitors of any other construction method is certainly no exception. 

Lets reveal the facts and truth here...

Whats going on today ? 

Oil submersion has been commonly used for audio path applications in capacitors as well as circuit breakers / relays up until the late 70s, and were loved amongst the first Microphones pioneers.

Albeit today, such components are only rarely produced by A small group of manufactures.

Because a lot of new production techniques have taken over the way the audio gear industries today produces the audio tools with the main reason being smaller,

cheaper and easier to get by in large quantities.

Now more and more engineers discovered over the last decades that the old vintage recording gear and instruments sounded way smoother / musical and open and warm plus pleasing to the ears.

Quickly prices went over the roof, with some old vintages microphones

and guitars easily costing above 15k.

The legendary microphones like (u47- c12 - Ela m251) and many more were manufactured

using paper oil capacitors in the audio path, and not for just any economic reason!

But pure for the best sound chain possible

The extra benefits of using PIO caps include:

  • Suppression of arcing to a higher voltage than air

  • Improved cooling of local heat spots due to circulation of the fluid

  • Improved insulation between the contact electrodes,

  • having a higher dielectric constant than air

  • Elimination of bubbles within the paper or film,
    or between electrodes, avoiding sporadic arcing and variation in characteristics

some sources will tell you that there is no scientific explanation of why paper in oil capacitors will give you better tone when used in an audio circuit. But it is a well known fact in the high-end audiophile community that paper in oil will be warmer, smoother and have more "Sparkle" than any other capacitors.

We at ZP microphones have built our own custom transparent microphone circuit that is able to reveal the sonic signature each part applies. We found that some being of the same value and size and material construction, but different brand could alter the sound, and started to test every type of new and old nos' capacitor we could get our hands on.

We quickly came to realize there are huge beneficial differences when using pio caps

and this totally explained why the legendary microphones just sound so fantastic.

The debate many people encounter when some claim not hearing A change has many factors like wrong point of  implementation in the audio path and choosing the wrong schematic that will mask the sound and in some cases not enough trained ears to appreciate the subtle higher grade audio.

Some engineers will be fine using a low budget microphone or instrument and hear no benefits when using A vintage legendary tool because the sonic qualities that will translate go hand in hand with the professionalism / trained ears of the listener.

In All Our Microphones we implement the finest new produced and N.o.s (new old stock) PIO capacitors that fit the schematic and custom tuned capsule for A audiophile sonic signature

and let you capture sound source just like the legendary high-end microphones did back then.

bottom of page