Hi Scott,
As I recall some of the phono stages you've tried in the past have had issues involving pickup of radio signals. So in part for that reason I wouldn't totally rule out the possibility that the means by which the air conditioner is causing the issue is by coupling of RFI through the air, rather than by its effects on the power line. Especially if the air conditioner is located in the same room as the phono stage.
And also given that a Furman power conditioner didn't resolve the problem, as some of their models provide very good filtering down to the low kHz range. What model Furman was it? And did it seem to make a perceivable difference in the severity of the problem?
Best regards,
-- Al
As I recall some of the phono stages you've tried in the past have had issues involving pickup of radio signals. So in part for that reason I wouldn't totally rule out the possibility that the means by which the air conditioner is causing the issue is by coupling of RFI through the air, rather than by its effects on the power line. Especially if the air conditioner is located in the same room as the phono stage.
And also given that a Furman power conditioner didn't resolve the problem, as some of their models provide very good filtering down to the low kHz range. What model Furman was it? And did it seem to make a perceivable difference in the severity of the problem?
Best regards,
-- Al