Coupling cap upgrade for Cary CAD-805C help

I have rolled all kinds of high end caps in the coupling position. The Mundorf SGO caps are good, but nowhere near the glorious sound and dead quiet background of the Duelund CAST caps.

The two best I have heard in tube amps and preamps are..

Duelund CAST caps
JB JFX Premium film caps

The JB caps come very close and only cost $3-$10 depending on size. They can be purchased at Just Radios in Canada.

They are not quite as extended in the top end as the CAST, but give little else up. The CAST have a blacker background also. the JB's have better bass and are a little warmer sounding without giving up any detail. I know it is hard to believe a $3 cap can sound that good, but they do. I prefer these over the Mundorf SGO's as well as several other Aphile friends that have tried them and now use them.

Dear all,
I'm going to swap the coupling caps of my Cary CAD-805C (those with 845 triodes). The original are strange "Audio 1" PIO capacitors - they looks like Vitamin Q maybe. I'd like to put there Mundorf SG, to have a more dinamic sound. Service manual says that the 300B to 845 coupling is made by IS trafo and in parallel with.. a parralel of 2uF + 0.22uf PIO capacitor. In my 805C I have only 0.22uf. Do you have any experience? Thank you, 
Best regards
Marcello

Dear all,
I'm going to swap the coupling caps of my Cary CAD-805C (those with 845 triodes). The original are strange "Audio 1" PIO capacitors - they looks like Vitamin Q maybe. I'd like to put there Mundorf SG, to have a more dinamic sound. Service manual says that the 300B to 845 coupling is made by IS trafo and in parallel with.. a parralel of 2uF + 0.22uf PIO capacitor. In my 805C I have only 0.22uf. Do you have any experience? Thank you,
Best regards
Marcello

Yes. This summer my local tech removed the original "Audio1" caps (did not sound too bad) and we installed the new Mundorf SVO Silver Gold coupling caps and Hexfred diodes in my Cary CAD-280SA V12R tube amplifier.  While the Cary Audio Design V12/V12R was based on the Cary 805, I would not venture to guess, it's better to open it up and check or call Cary Audio as others advised. 

After about 100hrs on the Mundorf SVO Silver Gold coupling caps really start to come into their own.  Very happy about the investment in this upgrade.  The V12R now has added detail and 3rd order harmonics.  Tube changes are a bit more noticeable now too.  

Dear all,
I'm going to swap the coupling caps of my Cary CAD-805C (those with 845 triodes). The original are strange "Audio 1" PIO capacitors - they looks like Vitamin Q maybe. I'd like to put there Mundorf SG, to have a more dinamic sound. Service manual says that the 300B to 845 coupling is made by IS trafo and in parallel with.. a parralel of 2uF + 0.22uf PIO capacitor. In my 805C I have only 0.22uf. Do you have any experience? Thank you,
Best regards
Marcello

Yes. This summer my local tech removed the original "Audio1" caps (did not sound too bad) and we installed the new Mundorf SVO Silver Gold coupling caps and Hexfred diodes in my Cary CAD-280SA V12R tube amplifier.  While the Cary Audio Design V12/V12R was based on the Cary 805, I would not venture to guess, it's better to open it up and check or call Cary Audio as others advised. 

After about 100hrs on the Mundorf SVO Silver Gold coupling caps really start to come into their own.  Very happy about the investment in this upgrade.  The V12R now has added detail and 3rd order harmonics.  Tube changes are a bit more noticeable now too.  

Hi Decooney,
thank you for sharing your experience! Hexfred diodes and fresh electrolytic capacitors will be my next upgrade, but once per time, so I can evaluate the single upgrade.
About "my" issue, I'm looking for a CAD-805C expert. AFAIK Dennis Had told that there is two versions of the C model, one of the differences is the IS coupling transformer. Maybe a different coupling cap (2.22uf vs 0.22uF) to match the different impedance?