Hey Jamie, have you considered Mundorf caps? I recently fitted 1.5uf Mundorf Supreme Silver/Oil output caps into my S.E.X amp and they are sublime. For the interstage caps i'm using .1uf Russian FT3 teflons. I'm still stunned how much of a difference they made to the amp, but a little worried that i find myself back reading this thread again
Hi the large uf Mundorfs were a bit pricey for me, size wise there is not much wiggle room also. Its helpful to know of your experience with your SEX thanks I am very tempted to build one of them at a later date and have a speaker project I am mulling over to base round it. Maybe later in the year.
I do have some more info on the JB JFX which I decided in the end to purchase. Fingers crossed they will be a worthwhile upgrade we will see.
Following on from my earlier post, the JFX-Premium metallized polypropylene film capacitor intrigued me and there is something about taking the path less travelled that I find attractive compared to running with the more obvious tried and tested choices for upgrading the caps in the Crack.
After some considerable time spent online getting nowhere I ended up contacting JB Capacitors direct in China.
It turns out that they have a 30 year history of capacitor manufacturing with modern machinery and production methods achieving high consistent quality to meet many international accreditations.
On to the JFX-Premium metallized polypropylene film capacitor.
These are built to high specification and JB state they regard their JFX product as being of equivalent quality as the more well know brands such as Jensen, Auricap, Erse, Mundorf, Auricap, Erse, Mallory, Jantzen Audio. Which is not a claim to make lightly I would think.
A premium grade of “defect free” aluminium metallized polypropylene film was chosen from an industry leading film supplier. All leads are lead free (RoHS Compliant), oxygen free 99.99% pure copper. Each lead is attached to the body of the capacitor with ultrasonic welding. To further reduce equivalent series resistance and improve long term reliability, the leads are then soldered with lead free silver solder. JFX caps are then wrapped in flame proof polyester tape and the ends are epoxy filled. Before final packing, each JFX cap is tested with certified premium quality Wayne Kerr capacitance bridges to insure the ±3% tolerance nominal value.
This seems to be born out as my two capacitors are matched 102.35uf and 102.27uf 0.08uf difference so to within 0.08% this seems a good sign with regards to consistency of their manufacturing.
Interestingly I also found out that Mundorf approached them to manufacture the JFX as OEM part for them so they could create a new premium brand to sell under the Mundorf branding. JB decided not to pursue this as it did not add value to their own brand which they want to promote with the JFX.
The JFX range is promoted
“The JFX caps display signs of a near perfect capacitor. Total harmonic and IMD distortion and phase distortion are virtually immeasurable, while all losses are near zero in every aspect. jb JFX caps will allow your music to be accurate and uncolored in every way.”
Taking a path less travelled was to appealing so I decide to go with JB JFX premium films over the Obbligato's being smaller they fit in the BH Crack nicely. Initial observations they seem well made no obvious flaws they arrived quickly, well packaged and with associated measurements from Audiocap UK. The labelling is not printed onto the capacitor itself but on a adhesive film that is wrapped around the capacitor. There are no markings as to which lead is connected to the outer foil so you would need to test if you wanted to connect in a particular orientation. From what I have found this is common practice in this price range and as you move up the price ladder this feature becomes more available on some but not on all of more well known premium bands.
My Caps
