Novelty Caps: Gudeman paper in oil
When i found these oddballs on eBay i just had to have them. They are a paper in oil construction housed inside a hermetically sealed glass enclosure, rated at .1uf 5000vdc. I've had these on my desk for a few months which provided constant amusement watching the air pocket slowly move around inside the glass, and i mean slow as it takes hours for anything to happen. I don’t know why but i found that oddly amusing.
I have no idea what these were originally intended for as there cant be too many applications requiring 4-5kv rated caps. I haven’t been able to find very much information about Gudeman as a company other than they were based out of Chicago Illinois and produced a whole range of paper/oil caps around the 1950's and 60's. They also seem very popular with the vintage Guitar community in tone circuitry, but little to no information was found regarding these glass cased high voltage caps.
On my capacitor testers both of these measure exactly .1uf and have no leakage up to 450v dc so they are still perfectly healthy. With that in mind i removed the Russian Teflon FT-3's from my S.E.X. amp to see how they perform. My expectation going from a Teflon capacitor to a Paper/Oil was a rolled off high end, and a thicker sounding presentation through the midrange. Certainly that has been my experience in the past with different Russian PIO flavors. That is not really what i found at all, there is an almost imperceptible difference in high end detail vs the teflons, the midrange is very similar with maybe a tiny bit more warmth and smoothing, and a noticeably less rolled off low end. I was expecting this to be a quick experiment before i soldered the FT3's back in but instead i found myself sitting up straight and paying attention.
The first big difference i have noticed is how much energy there is dynamically making the FT3's sound thin and weak in comparison. Movies with a recorded low frequency effects sound channel "LFE" have real powerful energy behind them now. Its not a case of an over emphasized or overpowering low end, but more a realization of how much of the impact i was missing before. If a kick drum goes thump, it goes thump!, not a bump.
The other big difference, and the one that has surprised me the most is its almost holographic presentation of the music. If you have ever heard a binaural recording where the soundstage has moved outside your expected boundaries to the point of startling you, that is kind of what i am experiencing. I have been listening to these caps for days now with different headphones and music and i still can’t wrap my head around what i am hearing, there are layers and depth of instrument separation and positioning that just wasn’t there before. I just can’t seem to rationalize it which is driving me nuts, but on the other hand i have been rediscovering my entire music collection again and loving it.
Is it possible the FT-3's aren’t really as good as everybody makes them out to be? or have i just stumbled across something rather special? or gone a little insane?
