P12: Phase Tuning -> Output Voltage

Just setting up my P12 (upgraded from P5).

Am asking the P12 for 230v out. With phase tuning at zero the output hovers around 229.5. With auto tune (-2) it drops to 229.3. If I manually set phase to +4 I get voltage out bang on 230v.

Haven’t done any subjective evaluations yet but am wondering whether I am wrong to fixate on getting the number I want or should I accept the lower voltage and the auto-tune result?

Output THD is 0.1 regardless of phase.

I would let the auto-tune do its thing. It’s probably setting a slightly lower voltage for a reason. What that reason is, I have no clue, but it must be doing for some reason.

I don’t care at all about the Auto Tune because I get much better values if I set the Phase Tune to either -2 or -3 while the Auto Tune most often suggests 0 or +1

Any chance we can get an authoritative comment on what Auto-tune is trying to do in regards to phase-tune? With Multiwave it sets phase-tune to 2, with sine wave 3 in my situation.

I have 5.1% THD in and and have seen it over 6% (could running the AC affect thd?..), .1 out …fwiw.

from the p12 manual:
Phase tuning is the next adjustment. Increasing or decreasing this will move the point at which the P12 detects the incoming waveform as the wave crosses the 0 voltage point. In places where the AC power is especially poor making small adjustments to this setting can potentially lower the THD output. The best recommendation would be to keep this at zero unless you are seeing THD output higher than 1-2%.