hi Ken, at least i try to keep my opinions humble.
anyway, i would guess that the volume control that is in the Berning ZH-270 would be bettered by the Placette but when i had the Berning in my room i didn't try it with it's own volume control. typically, the arithmatic does not allow for the quality of Vishay stepped attenuator like the Placette in an amplifier in the price range of the Berning.
i have found that typically the quality and execution of any volume control is a much bigger issue that an additional interconnect in performance. any volume control changes the sound.....an interconnect passes the sound. i have owned the Nordost Quattro fil and it is an excellent interconnect and very neutral. so...IMHO...the Placette with an additional Quattro fil would sound better than the Berning volume control without the additional interconnect.
as far as the Joule verses the Placette the Placette is probably more transparent but not necessarily better in your system. Transparency is not everything.....you would need to compare the two and chose the more musically satisfying of the two. again, the Placette will not add any warmth or body, with the Berning ZH-270 being fairly neutral it would depend on your speakers.
i hope that helps.
anyway, i would guess that the volume control that is in the Berning ZH-270 would be bettered by the Placette but when i had the Berning in my room i didn't try it with it's own volume control. typically, the arithmatic does not allow for the quality of Vishay stepped attenuator like the Placette in an amplifier in the price range of the Berning.
i have found that typically the quality and execution of any volume control is a much bigger issue that an additional interconnect in performance. any volume control changes the sound.....an interconnect passes the sound. i have owned the Nordost Quattro fil and it is an excellent interconnect and very neutral. so...IMHO...the Placette with an additional Quattro fil would sound better than the Berning volume control without the additional interconnect.
as far as the Joule verses the Placette the Placette is probably more transparent but not necessarily better in your system. Transparency is not everything.....you would need to compare the two and chose the more musically satisfying of the two. again, the Placette will not add any warmth or body, with the Berning ZH-270 being fairly neutral it would depend on your speakers.
i hope that helps.