House Amperage vs Stereo Amperage

Amplifiers store charge in the capacitor reservoire to permit short-term high current output. If an amplifier really needed a 30 amp draw from the wall, it would have a different power cord. Most wall outlets are limited by wiring and breaker to 15A.

15 amps at 115 volts represents 1725 watts...more than your toaster! Think what this would do to the tender voice coil of your speaker. Obviously the average power delivered to the speaker is only a few watts. Speaker sensitivity typically runs about 90 dB for 2 watts. 90 dB is quite loud.

If you stand on a wet concrete floor and place a finger over the positive and negative poles of capacitor of a recently turned off amplifier you will find (via your hair being on fire) that energy is, indeed, stored in capacitors, not transformers (except as the transformer acts like a capacitor as a by-product).

I am not aware of any home audio transformer that requires 30 amps steady state(roughly 3700 watts at 115v).

If you are curious about your audio current draw buy a "Kill a Watt" digital meter through Ebay which will give you a real-time amperage/wattage reading.

I am not connected to "Kill a Watt" in any way or have one for sale.

Don't confuse average power with peak power. Peak power comes from caps and can be more than 15 amps but you are playing really loudly by that point. Average power will be A LOT lower -hard to say exactly because it depends on lots of variables.

Amp efficiency also plays a part, most class AB amps being 40% efficient or so. My McIntosh amp meters rarely average 30W with pretty sensitive JM Lab speakers. Factor in efficiency and the amp draws about 75W from the wall (which is less than 0.7 amps). Arthur

All good points. Remember, as I said at the beginning, if the amp has a standard wall plug, it was designed to expect no more that 15A from the wall!

Kal