I'd go ahead and request three dedicated lines: Power amp, digital equipment and other (this assumes a cost of about $50-$75 per dedicated line). If you want a bit of insurance, you may wish to consider two to three more: Future second mono amp, TV / video (if that is in the same area) and analog if you are considering going there in the future. Unless there is an issue with the total fuse box capacity, the 20 amp circuit provides more future upgrade potential.
I am also building a house and have five dedicated lines at 20 amps each: Power amp about 5 ft left of center, power amp about 5 ft right of center and three circuits in the middle. I chose to go with 10 guage twisted solid wire (Southern Wire Co available at Lowes or Home Depot). I've left additional length (i.e., there is about 10 additional feet of wire between the outlets and fuse box) in the event I choose to go with a star grounding scheme later and add another ground rod. I'd love to go with ceramic fuses but am running into some code issues around that.
Search some prior posts -- there are a ton of them on the topic and there's lots of great advice. Look up "dedicated line". Good luck. Don't forget the outlets -- lots of good choices here too.
I am also building a house and have five dedicated lines at 20 amps each: Power amp about 5 ft left of center, power amp about 5 ft right of center and three circuits in the middle. I chose to go with 10 guage twisted solid wire (Southern Wire Co available at Lowes or Home Depot). I've left additional length (i.e., there is about 10 additional feet of wire between the outlets and fuse box) in the event I choose to go with a star grounding scheme later and add another ground rod. I'd love to go with ceramic fuses but am running into some code issues around that.
Search some prior posts -- there are a ton of them on the topic and there's lots of great advice. Look up "dedicated line". Good luck. Don't forget the outlets -- lots of good choices here too.