Amp info ????

[Serratoga]

I would like to know why some manufacturers want you to use a dedicated 20 amp circuit?
My krell KSA 100s manual states to to do just that? Can some one please take a moment of their time and explain to me in layman's terms why this is so ? I would really appreciate this
Thank You.

Slate

[davidallancole]

I believe this is a Class A amp rated at 100W per channel from what I have found?

If so, you could be looking at a continous power draw of 400 watts per channel ading up to 800 watts total. The power supply in an amplifier tends to pull current in only for ~ 10% or less of the 60 Hz ac waveform, so having a seperate 20A line will keep the power supply happy. With this seperate circuit, the resistance of the ac line can be kept down and the only thing drawing current will be your amplifier off of this circuit thus effectively clipping less because the power supply will be able to charge up just that much more.

[FastEddy]

" ... so having a seperate 20A line will keep the power supply happy. With this seperate circuit, the resistance of the ac line can be kept down and the only thing drawing current will be your amplifier ..."

Exact 'em wah ... seperate power line = seperate filtering considerations & a seperate breaker = some isolation from your other equipment ... but mostly for davidallancole 's suggestions about the power you could draw on that line ...

[Serratoga]

What if I don't listen to loud music, only softly, does it still need the power?
Thanks for the replies guys.......

[davidallancole]

You will have way of an over-kill of an amp there just to listen to music quietly. I am guessing it draws a lot of power because its class A and high power, thus drawing a lot of power on a continues basis, thats why it would benifit and possibly need a second circuit.

You could sell this amp and by a lower power one like a 10 watt class A if you are listening to music quietly or a more efficient class ab amp to still have those power reserves without having a large continous power draw.

[Serratoga]

Thanks for the reply David,
So lets say regardless of how loud I listen to my music, the amp should always have a 20 amp circuit, a nice flow of power......?

[davidallancole]

Sorry if you got that inpression. The seperate circuit would be getting towards optimum conditions for the amplifier but it should still run fine on any plug in your house.

My intent was to explain why its better to have that seperate circuit. You could trace a circuit and make sure nothing else is plugged into it and use that plug easily without getting a seperate circuit installed.

[FastEddy]

" ... What if I don't listen to loud music, only softly, does it still need the power? ..."

Yes somewhat. "Starving" the amp power supply could possibly cause damage = increasing internal heat, even at low levels ... and you will still have the possibility of visiting nieces & nephews crankin' 'er up before you can get your hand on the throttle ... and these gadgets draw power even at idle.

#14 AWG Romex wire is cheap = less than $1 USD per foot. 15 Amp circuit breakers are also cheap = less than $10 USD ... Yes? ... If your new line length is greater than ~ 25 feet, then use #12 AWG Romex and a 20 Amp breaker = add another ~~ $10 USD.

100 Watts (conservative) X 2 channels = 200 Watts, 200 Watts with inefficiencies = maybe 500 Watts actual power required = approx. 5 or 6 Amp rating (on the back labels), Yes? ... plus any added pre-amps and players, tuners, etc. = 750 to 800 watts, max. So, the use of the lighter #14 AWG gauge power wiring is called for without concern or compromise up to a maximum of ~~ 100 feet. (Just run it out the window and around in back to the sub panel ... )

Power considerations aside, it is a good idea to have a separate power run for your audio gear, just to get a better handle on noise ...

[Serratoga]

Thanx Fast Eddie,
That is exactly the information I was looking for....................

[unclejed613]

some pro-audio amps REQUIRE separate circuits, especially if they're being used at their rated power, usually in the range of 1800W or so.... that usually isn't a problem in most concert halls, but it can be in night clubs. for a power amp with about 400W of idle power, it shouldn't be a problem in your house, unless you have power-hungry appliances on the same line. the simplest way to check what else is on the line you plan to use, is to plug in low wattage (anywhere up to about 60W or so) into all of your outlets, and turn off the circuit breakers one by one, and keep a list of what outlets go to what breaker...