Continuation from JVC XL-MV33
My skeptical friend finally decided to get his toes wet with minor recapping on the MV33 to improve reproduction.
Upon reviewing the PCB with the output RCA connectors ... I found some typical Japanese poly capacitors encase in a yellow plastic casing. These type of poly capacitors were common in Japanese brand products from the 1980-1990's (see my past article on them) and are most likely the culprits of the audio reproduction barrier - not all need to be swap out unless they are in the audio pathways.
My skeptical friend finally decided to get his toes wet with minor recapping on the MV33 to improve reproduction.
Upon reviewing the PCB with the output RCA connectors ... I found some typical Japanese poly capacitors encase in a yellow plastic casing. These type of poly capacitors were common in Japanese brand products from the 1980-1990's (see my past article on them) and are most likely the culprits of the audio reproduction barrier - not all need to be swap out unless they are in the audio pathways.
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| Original output PCB |
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| Part of output schematic for MV33 audio reproduction |
The MV33 schematic from HifiEngine confirms only the ELNA EC (47uF 50V) and the yellow encased poly (1500pF) are on the audio pathway between the JRC OPAMP and the RCA outputs. The 220pF capacitors on the schematics were not present on the PCB - replaced by resistors.
As my skeptical friend was unconvinced of how much improvement can be obtained, I proposed initially changing only the two poly capacitors on the audio pathway (1500pF) - should be quite a revelation for him. Used a pair of BC (aka Philips) 1500pF poly for the swap-out.
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| ELNA EC and the Japanese poly swapped out |
For the first 30mins after the swap, voices were high pitched with the rest of the material sounding a little off-pitch. Thereafter the reproduction was much improved with the HF(s) sounding more natural and precise.
Even so, the overall presentation seem incomplete ... as if there was still some fog in the area. Next the ELNA EC(s) were replaced with audiophile grade Nichicon MUSE and a bypass ... the presentation improved quite a lot - reproduction was now much cleaner and begin to sound more like a decent CD player.
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| PCB after capacitor swap-outs |
As my friend was not adventurous, we did not proceed any further. He wanted to enjoy the new improvements for the time being.
