I’m curious about the noise my P12 injects into the line.
The following are typical measurements as taken with an Alpha Labs Line EMI Meter:
Wall 350 mV at 121 AC Volts
P12 1900 mV 118 AC Volts
Topaz Iso-Tran (after P12) 90 mV 121 AC Volts
Measurements from P12 front panel:
AC Volts In 125
AC Volts Out 120
THD In 1.9%
THD Out 0.1
So, there are contradictions in readings between Alpha Meter and P12. I do have another meter made by Entech which seems to correlate with the Alpha Meter.
This brings up questions for me:
Should we assume the P12 measurements are more accurate because of the cost difference to that of the Alpha meter?
If we are to assume the P12 is correcting Voltage (as its’ meter reads), is that Voltage correction deemed more important to audio than the line noise the P12 injects into the line?
My current set up uses the Topaz Iso Transformer (which runs downstream of the P12) to clean up High Frequency common mode noise and it clearly cleans up the wide band noise created by the P12.
All this being said, I’ve been evaluating the the sound between my amp coming straight from a dedicated wall line or from the P12 and I think I may prefer sq coming from the P12 (though it’s close.)