I am listening at a low ~ medium volume level, fearing trip the circuit breaker.You can crank the volume up as much as want. The 10 amp Line fuse is a lesser value than the 15 amp breaker. The actual FLA on the amp is more than likely 8 amps or less. (8 x 125% = 10). Keep in mind that is continuous amps. Pushing the amp full bore. The 15 amp breaker will handle a continuous load of 15 amps all day long. It will pass short spurts of current well above 15 amps all day long. (Of course you have to take into account any other loads that are connected to the same branch circuit).
Your problem with the 15 amp convenience outlet branch circuit could be/will be VD (Voltage Drop) if you push the amp to hard. Basically starving the power supply of the amp. The caps in the power supply will have problems recharging.
.
.
Subject line is in regards to a power cord but the same would hold true (probably more so) for a 15 amp convenience outlet branch circuit for the amp you have.
Ralph - Manufacturer, Atma-Sphere Music Systems
There are two aspects, AC voltage drop and high frequency current limiting.https://www.audioasylum.com/audio/cables/messages/17/174988.html
AC voltage drop is the voltage dropped from the wall to the input of the equipment in use. I’ve measured a loss of 40 watts on an amp that makes 140 watts, so no-one should be surprised that that might be audible as well. I used a 3 1/2 digit DVM to measure the voltage drop and it showed around 3 volts. This was a pretty standard but inexpensive Belden cord. A more expensive Belden cord with heavier gauge showed a lessor drop and more power out of the amp. So no mystery here.
The second issue is the high frequency current limiting. This is a bit trickier to understand, but its not quite rocket science. Almost any power supply consists of a power transformer, rectifiers and filter capacitors. When the the transformer voltage is higher than the capacitor voltage, the rectifier commutates (a fancy word for turns on and conducts). At that point the filter capacitors can charge up and will do so until the power transformer voltage falls low enough that the rectifiers cut off.
At that point the circuit using the power supply drains the filter caps. Since this happens 60 times a second, the drain is usually not very much at all, so its only at the very peaks of the AC waveform that the caps are be replenished. There might be only a few microseconds or milliseconds that this can happen, and quite a bit of current might have to flow during that time, essentially a high frequency event.
If the power cord limits current during this period, the performance of the circuit using the power supply might suffer, possibly due to increased IMD since the DC might have a bit more of a sawtooth on it than if the current was not limited.
Nelson Pass
https://www.passlabs.com/press/power-supplies-commentary-consumers.
ARC recommends a 20 amp dedicated branch circuit. See page 2.
http://www.audioresearch.com/ContentsFiles/150M%20Manual.pdf