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Old 5th July 2004, 04:18 PM   #1
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Default coupling caps? RTX vs Jupiter wax

I tried both:

RTX: very detailed and neutral, lost a bit of musicality
Jupiter: musical, but not as much detail as the RTX

How can I do both??

Has anyone tried a Jupiter bypassed with a RTX???

I have a 0.33uF RTX and a 1uF Jupiter.

I also have sitting on my bench a 1uF North Creek Crescendo and a 2uF PPFX.

What should I do???

btw, this is in the coupling cap of a tube pre-amp.

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Old 5th July 2004, 05:31 PM   #2
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Default Re: coupling caps? RTX vs Jupiter wax

Originally posted by AudioGeek
I have a 0.33uF RTX and a 1uF Jupiter.
Try to parallel them. Chances are you might get the best of both, although I rather avoid paralleling caps.

I tried RTX in a past, but somehow they sounded cold and analytical, but also better than most other caps.

Observe outer foil orientation, as this also influences the sound.
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
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Old 5th July 2004, 09:14 PM   #3
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How can I do both??
I was quite surprised myself to find i prefered Jupiters to RTX. Never tried paralleling but suspect it probably won't work.
Wait for copper foil Jupiters?
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Old 5th July 2004, 09:33 PM   #4
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The performance of the Jupiters probably derives from a relatively low dielectric constant of the wax they use. The DC of wax can approach that of teflon (~2.0). I suspect paralleling a Jupiter with an RTX will give a melange in ways better and worse than a Jupiter or RTX alone, ultimately leaving you wanting more. Copper foil betters the plate's electrical properties by avoiding the highish resistance of tin and problems associated with aluminum, but offering what I can't help think to be future oxidization headaches, and a diminishing investment value. I personally think it best to hunt for a better dielectric. Foam PTFE or PE anyone?
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Old 5th July 2004, 09:39 PM   #5
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btw, this is in the coupling cap of a tube pre-amp.
While I've never tried the Jupiters, the MIT RTX I use in a tube preamp and the PPFX went into the amplifiers.

In that way all the detail preserved by the RTX is amplified by the preamp, where signal levels are smallest.
The more musical presentation is left to the amp, where I think the RTX is probably overkill anyway.

From what I hear from other people, the metalized PTFE caps are even slightly more detailed than the RTX while being more musically correct.

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Old 5th July 2004, 10:47 PM   #6
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PTFE caps. have a reputation for being wonderfully transparant. A good way to try PTFE, without going bankrupt, is to buy Russian surplus parts. If you search for PTFE capacitor on EBay, you will find listings by a Lithuainian fellow (Gintaras, IIRC) at pretty good prices. The seller has a 1st class reputation.
Eli D.
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Old 6th July 2004, 12:43 AM   #7
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Default Thanks!!!

well, what i did was left in the RTX, pulled out a battery bias scheme I had and replaced it with an Allen Bradley Carbon bypassed with a BG.

This has added a nice sense of warmth while keeping the detail.

Very musical too!!!

how about those mundorf silvers????
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