Power conditioner or outlet?

I think the presupposition for those who advocate plugging directly into the wall is the circuit is dedicated to that plug/amplifier. Otherwise, and depending on the current requirements of the amplifier, I don’t think its advisable to share the power fed to the amplifier with other electrical devices in the house, especially dimmers or appliances which turn on/off thermostatically. A simple test for the circuit is plug in a high wattage hairdryer in the shared socket and measure the voltage drop when you turn it on. Try the same with your power conditioner. A good power conditioner will/should have no voltage drop with a high wattage hairdryer running with everything else plugged into it.

cleeds, perhaps my choice of the wording “good” power conditioner was subjective and not properly used. The power conditioner I use is an old 65 lbs. hospital grade transformer-based cube with eight outlets. It puts out a consistent 124 volts whereas the adjacent wall outlet is normally around 113-115 volts. I can’t claim it’s a “good” conditioner since I have not made fair comparisons but it continued to deliver the 124 volts even when I plugged in my wife’s hair dryer. I assumed, perhaps naively, that this was a sign of a good conditioner.
Edited to add that the conditioner is plugged into a dedicated 20 amp circuit.

"it’s not so much the voltage that’s critical, but the current, and no simple voltage regulator can increase the available current - it’s the law of conservation of energy."

Sorry, I probably need a refresher on my EE but I thought one of the reasons folks invest in high quality power cords, dedicated circuits, or even care about high quality power supplies - both internal to the gear or external, was to avoid a drop in supply voltage as the gear, particularly high power amplifiers, draw current during peak demands as well as control sagging voltages during these swings.  Which part of the Ohm's Law am I missing?

"Just switched to PS Audio Power Plant 15 BEST Decision I ever made"

Can you comment on what audible differences you hear after adding the PS Audio box?