My amp, a Moscode 401HR, uses 8 amps at full power output (300 wpc). The amp NEVER reaches 300 wpc output. I'll bet it rarely reaches 200 wpc, and I sometimes listen at very loud volumes. My Lamm LL2 Deluxe preamp draws less than 1 amp. So, at the highest output I'm looking at 9 amps maximum. If I had monoblocks, I'd be looking at 17 amps maximum at peaks...but again, I'd never reach the maximum. Never.
So, for most home audio systems the bottom line is that 20 amps is more than enough amperage on one circuit for two monoblock amplifiers, a preamp, and an analog frontend. Now, if you're a member of Metallica, then this scenario may be different.
If you want to add a third dedicated line and your wallet allows for it, then go for it.
So, for most home audio systems the bottom line is that 20 amps is more than enough amperage on one circuit for two monoblock amplifiers, a preamp, and an analog frontend. Now, if you're a member of Metallica, then this scenario may be different.
If you want to add a third dedicated line and your wallet allows for it, then go for it.

