Amp and preamp on same outlet?

A well regarded equipment manufacturer told me having everything on the same line is optimum. I suspect this is related to the ground loop considerations Al posted.

This has nothing to do with ground loops which are an entirely separate matter (FWIW, if your equipment is properly designed, ground loops should never be a problem).

The concern with different lines is that one might be on one side of the incoming AC power into the house, the other might be on the other. Sometimes you can have leakage problems caused by the two lines being of slightly different phase (or a lot different phase if taken off of a 3-phase circuit). Sometimes this can result in hum. If the equipment is properly designed though this should be a minor concern.

IOW two different lines off of the same side of the incoming AC line (which is 240 Volts in the US and then gets split into 2 halves each 120Volts...) eliminates that concern. If your equipment is prone to ground loops that can still happen though...

Jea48, Asit turns out, my krell manual for my amp says to use 20 amp single pole breaker min, they put it in their manual, that means 20am will work, really terrible, but you can get by, the 30 amp single pole allows my amp to get the correct current, does it use all 30 amps, of course not!, however, it spikes well above 20 amps, the amp never runs hot like with the 20 amp breaker, way more dynamic, bigger sound stage, it's a fit!

Jea48, Asit turns out, my krell manual for my amp says to use 20 amp single pole breaker min, they put it in their manual, that means 20am will work, really terrible, but you can get by, the 30 amp single pole allows my amp to get the correct current, does it use all 30 amps, of course not!, however, it spikes well above 20 amps, the amp never runs hot like with the 20 amp breaker, way more dynamic, bigger sound stage, it's a fit!
02-26-15: Audiolabyrinth

Audiolabyrinth,

I am sure the Krell user manual says the amp should be connected to a 20 amp circuit. They did not a have a choice if they wanted to use a NEMA 5-15P or a NEMA 5-20P plug and cord to feed the amp.

Just going from memory in another thread here on Agon you and I have discussed the code violation of using a 30 amp breaker on a 20 amp branch circuit that uses NEMA 5-15R, (two or more), or NEMA 5-20R receptacles connected to the branch circuit wiring.

If I remember correctly you used #10awg for your branch circuit wiring instead of #12. I believe in that thread as well as this thread #10 wire I said why #10AWG wire does a better job of controlling VD, voltage drop, placed on the circuit caused by the Krell amp. As I said in the other thread the current carrying contacts as well as the other current carrying conductors in a 20 amp breaker are exactly the same as 30 amp breaker. Only the magnetic and thermal trip units settings are different.

I may not be able to convince you otherwise but it is my hope that others reading this thread or other threads like it will not think it is ok to use a 30 amp breaker in place of a 20 amp breaker.

If the current carrying components inside of a 30 amp breaker are larger than a 15 or 20 amp breaker then why would they sale for the same price?

Square D QO 130 single pole breaker.

Square D QO 120 single pole breaker.

Square D QO 115 single pole breaker.

If the 20 amp breaker felt warmer to the touch with the #10AWG wire connected to it the reason could be the breaker was defective. Again it had nothing to do with the differences in the size of current carrying metal components in the 20 amp verses the 30 amp breaker because there is no difference.
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Jim

Jim, science is not all!, I am telling you, please listen, My amp does not get hot any more, got a bigger sound stage, runs smoother, hugely more dynamic, Jim, how do you explain why a single pole 30 amp breaker did all this when a 20 amp breaker choked the crap put of my amp in every way?, also Jim, this is very incredibly noticeable of the difference between the 20 amp and 30 amp breaker on my amp,I also have a $240.00 top of the line furutech GTX-D Rhodium for an outlet with the breaker, works safly, the outlet is cold all the time, period.

Jim, take note: Never try to teach a pig to sing....