JPX – Supreme Metallized Polypropylene Film Capacitors, Axial

JPX – Test Reviews

Welcome to visit the latest customer testing report about jb JPX audio capacitors.

Below content is quoted from the test review, for more details, you can check the links listed at the bottom.


This is a very useful comparative review of sound capacitors for use in power amplifiers as pass-through in low-current signal circuits. Very often, manufacturers indicate extremely low levels of distortion for their products – Loss factor = 0.0001@1kHz, but in real conditions, the listening results are still very different!


Today very good capacitors for audio take part in comparative testing. They proved themselves in high-quality tuning of amplifiers – from cheap to expensive ones, and here is their list:


  1. RIFA PHE426 0 / 250V (polypropylene)
  2. WIMA MKS 2 / 63V (polyester)
  3. Mundorf MCAP MKP 7 / 400V (polypropylene)
  4. Mundorf MCAP EVO Aluminum Oil 6.8 / 450V (polypropylene) JB JPX 3.3 / 250V (polypropylene)

All capacitors are original, Mundorf MCAP MKP – is in the amplifier use by default.

The first audition was attended by Mundorf MCAP MKP and here are the results of the evaluation:


  • Mundorf MCAP MKP 7 / 400V (polypropylene) = rating 7 out of 10.

The sound of the popular MCAP budget is very smooth, this capacitor is often used by those who wants a popular brand at an affordable price. The sound stage is wide, the details of the high frequency are transmitted accurately, fast good bass. The disadvantage is a bit cold midrange, from which the sound becomes a bit dry and lifeless.


  • RIFA PHE426 1.0 / 250V (polypropylene) = rating 6 out of 10.

This is a Swedish producer and popular music series PHE426. The sound of these capacitors neutral and even, all the nuances are transmitted accurately, the bass is assembled, but the treble sounds a bit aggressive.


  • WIMA MKS 2.2 / 63V (polyester) = rating 4 out of 10.

A cheap capacitor from the German manufacturer, this is the only capacitor without polypropylene, but I included it in the review in order to understand how similar capacitors sound in other systems. They are very cheap and at the same time should be the best of all polar electrolytic capacitors that are often used in the cheapest amplifiers. No serious problems with the sound of the MKS were found, except for one – the HF was very muffled, many details in the correct frequencies could not be heard. This will not be noticeable on the budget system, but on our amplifier this capacitor turned out to be the worst variant because of the HF.


  • Mundorf MCAP EVO Aluminum Oil 6.8 / 450V (polypropylene) = rating 6 out of 10.

This is an affordable series of very high-quality capacitors, we have high hopes for its sound characteristics, but we were in for a surprise – EVO Aluminum Oil plays WORSE than MCAP MKP! This is an amazing fact, but it is true. We tried to change the polarity of the connection, soldered it twice and let it work for about 1 hour, but this does not need any result! The main problem of this capacitor is a very dark sound, almost deaf. Only LF and MF sound very beautifully, but HF seems to be absent. It’s hard to understand why…


  • JB JPX 3.3 / 250V (polypropylene) = rating 9 out of 10.

Even better after the JSX is the “red” JPX series. Before listening, I was sure that the sound would be very good 🙂 And I was right! It sounds even better than a very nice JSX, the sweets in the sound are now less – now it is the best combination of musicality and accuracy, very beautiful MF, excellent intelligibility of HF, very fast and deep bass. It was difficult for us to find a flaw, but perhaps at the most faithful HF a little bit lacking speed, but this is very little. Now I am almost sure that the top-end JLX series from JB – does not have this drawback, but unfortunately we do not have this capacitor for comparison.


TOTAL. Before the start of this review, I was almost completely sure that Mundorf would surely win everyone, but the reality turned out to be much more interesting! JB was able to demonstrate a more interesting sound two times and at the same time its cost is much lower than the popular Mundorf! I can safely recommend for low-voltage amplifier circuits JB JFX, JSX and especially JPX capacitors – this is a really amazing choice and the undisputed winner of our test!

Thank you for excellent product, jb Capacitors Company! ”


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  • Project Details

  • Date August 20, 2022
  • Client
  • Category jb-film-audio-capacitors,
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