House Amperage vs Stereo Amperage

Feedback around an audio amplifier enables it to properly follow the signal input even if the "rail" voltages fluctuate. If the rail voltage diminishes, the transistor (or tube) is just turned on more. I am sure everyone is familiar with the way that a power amp will continue to play for several seconds after it is turned off. During these several seconds the rail voltage "sag" is catistrophic, but there is little immediate audible effect.

Sean has a point, but... If an load device has the ability to draw more than 15 amps (steady state) it will not be certified by UL to be furnished with a standard Nema 5-15 (straight two prong one ground)power plug. If your product is designed to draws more than 15 amps on anything more than a transient basis and you equip the product with a 5-15 plug you are violating UL and NEC rules and leave yourself open to both civil and criminal liability if injury or property damage results.

There is no doubt that a load higher than 15 amps may be drawn for very brief periods(such as motor start or musical peaks)but, as noted earlier, these loads are transient. HD motors and audio-amplifiers usually have capacitors specifically to cover this temporary situation.

If you think your Sunfire can draw more than 15 amps steady state (no matter how inefficient the load) just hook it up to a Kill a Watt and use a test record for whatever frequency you want for as long as you want. I would be amazed if you show a 15 amp + draw and/or you pop a 15 amp breaker.

The point is this is why G-d and/or the EE wizards have created power inlet/output plugs rated for more than 15 amps. My air compressor and air conditioner have a NEMA 5-20 plug and require a twenty amp 5-20 outlet and circuit breaker.

This question sometimes goes into la-la land where there is a "mine (dedicated circuit) if bigger than yours". So, put in a 100 amp 4ga circuit if you must for your 100/100 watt amp. It might make you feel good but the electrons won't care.

Whilst the above discussions are all technically correct concerning wall plugs, UL, current draw by the amp, etc., has it occurred to anyone that Doc777 maybe confusing the current capability often quoted by big muscular power amps ?
This includes Sunfire, Musical Fidelity, Harman Kardon etc who frequently quote high current capability to drive difficult loudspeaker loads.
Currents way in excess of 30A are often quoted which is not so difficult to achieve with the higher power solid state amps.
With a typical 50Vdc rail voltage, and an extreme steady state case, this 50Vx30A=1500Watts and still within the 1725Watts of your typical wall plug.

Chipman...A good observation. I suppose one could have an amp with ten volt rail voltages that could put out 150 amps, which would be 1500 watts. It would probably work better as a welding machine than an audio amp.

Many thanks for all the help. Initially I felt my question might have been too "newbie" but I find my others concerns were answered too, like a dedicated 20 amp line etc. I love this room!