Upgrading coupling caps in K8020

Hi -
I’m upgrading the output capacitors in my K8020, the two caps of 4,7 microF named C21 and C22 in the diagram. In some other forum I’ve read that “it’s preferable to connect the outer foil to negative side or to the “nearest” negative side (input side on coupling application)”, see http://jimmyauw.com/2010/04/24/observing-inner-and-outer-foil-of-some-popular-capacitors/comment-page-1/#comment-130841

I’ve asked with Mundorf, and they say that “Please use the beginning of the writing of the capacitor as a positive pole and the end of the writing as a negative.” I need to be sure: Should I put the end of the writing on the Mundorf caps closest to the tubes or closest to the output RCAs?

Thank you!

Sorry, we do not have any experience with this.

Some people prefer paper types . One unexpected type is motor capacitors typically made by Ducati or LCR . These are polypropylene and high voltage . Some people say the physical size helps . Capacitance up to >30 uF in non polarized . I suspect there can be differences in sound due to connection . There will be no functional difference . Please let them settle before snap judgements . 1 week of use is best .

The products you mention are highly respected .

Hope this is useful ?

Thank you for your advice! My impatience led me to try out the Mundorf Supremes 4,7 μF already in June. They were to big to fit in the K8020 box, so I built an extra box from aluminium sheet, drilled four 2 mm holes in the right side panel of the main box, threaded Mundorf silver-gold wiring through the holes and soldering them to the pcb. (By the way, I built the entire K8020 using Mundorf silver-gold soldering.) The Supremes made a huge difference in sound. Instrument definition and dynamics were significantly improved. So even though the outer appearance of the preamp was distorted, the sound benefit was definitely worth it!

However - another preamp project of mine is on hold for the time being, due to lack of time and some design problems. The coupling caps of this preamp is also 4,7 μF, and by November 2012 I remembered I already had bought two Mundorf Silver/gold/oil (sgo) capacitors for this project. I realized there was no sense in leaving those to gems sitting idly on the shelf, so I built another, and bigger aluminium sheet box and replaced the standard Supremes with the fist-big sgo’s.

This upgrade transformed the K8020 to a high-end preamp, with incredible depths of definition throughout the entire frequency range, dynamic power, smooth details and huge sound stage capabilities. A week ago I changed vacuum tubes, from Genalex Red Lion (new issue) to Brimar 13D5 NOS I acquired through a friend. The sound at home now is some of the best I have ever heard, with rock solid stereo positioning, a huge but believable sound stage and instrument definition of profound qualities. My friends say the set-up sets a standard in naturalness.

So for now I can sit idly back listening to music for a while, until my audio restlessness commands further efforts to realizing my Transcendent Sound Grounded Grid preamp project.

The attached image shows the K8020 opened with the two sets of caps and the two aluminium boxes to the left.
flickr.com/photos/finnsbilde … otostream/