jbcapacitors blog

Samples Tested by Mr. HF Choi
jb JSX - Superior Metallized Polypropylene Film Capacitors - Axial
JSX  1.0uF 250V +/-3% Bulk RoHS,  4pcs 

Datasheet link: http://www.jbcapacitors.com/pdf/JSX-Superior-Metallized-Polypropylene-Film-Capacitors-Axial.pdf

Introduction of Mr. HF Choi
My name is HF Choi I am in the UK and looking for quality JSX cap for DIY hifi.  

Original letter from Mr. HF Choi
I received the capacitors a couple weeks ago and have installed them in my DAC.

I installed the 4 JSX 1uF caps as bypass on the output electrolytic caps of the DAC (2 caps per channel, each 150uF), so the bypass was less than 1%.
Immediately on first listen I could hear that the bass was bloated and the soundstage was closed in but the treble was a bit sweeter.

I let the DAC continue to play for 50 hours after which the bass improved dramatically.  It sounded like an extra octave lower was added.
Also, the treble was becoming more tangible and fine details throughout the frequency range became audible whereas before they were not.  
Nuances now audible in the music making instruments sound more real changed the tonality of entire pieces of music.
It slowed the music down somewhat for some fast bass music but also sped up music with fast transient treble.
Nice, as this probably means there's now less signal smearing and timing issues.

I find there's now a less of a difference between redbook tracks and DSD tracks.  
Both sound smooth and detailed now but DSD more dynamic with good recorded material.
Still very enjoyable with the improvement in tonality, timing, low level detail and nuances, and improved frequency extension - and of course price is very good. I’ve used them for hundreds of hours so far.

I chose the JSX because of the small size. Compared with large and expensive Mundorf and similar grade caps, it is an easy choice. Very high price/performace ratio with the JSX.
I am very satisfied with the performance of the JSX . Thanks for a great product! 

Samples tested by Mr. SAM BENELBAZ
jb JFX—premium metallized polypropylene film capacitors
JFX 94uF 250VDC +/-5% Bulk RoHS, Qyt: 2pcs
JFX 22uF 250VDC +/-5% Bulk RoHS, Qty: 2pcs
JFX 3.5uF 250VDC +/-5% Bulk RoHS, Qty: 4pcs

Datasheet link: 
http://www.jbcapacitors.com/pdf/JFX-Premium-Metallized-Polypropylene-Film-Capacitors-Axial.pdf

Introduction of Mr. SAM BENELBAZ

French, retired, have the hobby of TUBE do it yourself; used to work in IBM as a professional 
of electronics; after that for LASER a company involved in point of sales solutions and hardware maintenance, in that position, he bought a French company sic-safco. 

Mr. SAM BENELBAZ is member of some forums in US and France, some are AUDIOASYLUM.com and DIYAUDIO.com fun withtubes. com and some others.

Original letter from Mr. SAM BENELBAZ

Dear iris,
i hope you are ok. 
I have installed the JFX capacitors last Sunday and i can now give you my impressions.

But first i have to tell you what speakers and amps i used for the test:

The speakers are YAMAHA NS1000M well known in the market and very revealing .
The amps are two american CARY tube amps model 40M using 6SL7 and EL34 tubes.
In this test the EL34 are NOS Philips EL34 of the XF2 series (the best).

The Yamaha crossover was using mainly NICHICON capacitors using metalised paper .
I did replace every capacitor with the ones you send me.
The CDs i use for the test are very good Cds , classic music and jazz mainly.
I know them very well and can hear the differences well.