Amp and preamp on same outlet?

IMO; it really depends upon which amp and preamp you are using. You never specifically mentioned that.

Many ARC products are made to be used with a 20 amp IEC power cord, is yours?

I would try plugging the amp into the wall outlet and then run a heavy duty extention cord to your preamp (using whatever connection adapters necessary) and listen for yourself.

As Yogiboy mentioned, if the breaker has not tripped then you should be fine however the system might sound better if the amp and preamp were on different circuits or dedicated circuits.

Using separate outlets, especially if they are on separate runs back to the breaker panel, will reduce the amount of amplifier-generated electrical noise that may couple back into the preamp. On the other hand, doing that may increase susceptibility to ground loop issues, including high frequency electrical noise as well as low frequency hum. If the connection between preamp and power amp is balanced, the likelihood of ground loop issues is considerably reduced.

All of this is highly dependent on the design of the particular components, and has little if any predictability. So ZD is right, "there's no way to tell unless you try it." But if, as you say, "it sounds great as is," that would seem likely to be the bottom line.

Regards,
-- Al

Audiolover718,

Depends on your circumstances.

How big is the ARC amp? What is the ARC model number?

What size is the branch that feeds the amp? 15 amp? 20 amp?

What is the length of the branch circuit wiring from the panel to the outlet receptacle the preamp and amp are plugged into?

How many other duplex receptacles and possibly ceiling light fixtures are connected to the same branch circuit your preamp and amp are plugged into? What was the wiring method used to wire the receptacles that feed onto the next receptacle of the branch circuit? Wiring daisy chained using the duplex receptacles to make the in and out wiring connections of the branch circuit wire? Corroded/loose/poor connections add resistance to the circuit. The more the load placed on the circuit the greater the VD, voltage drop. How much is the other non audio connected load connected to circuit?

All the above can affect how a piece of audio equipment will preform. Branch circuit breakers are designed to trip open in the case of a continuous overload condition, a high sustained inrush current condition well over the handle rating of the breaker, or a short circuit event.

The breaker does not respond to short bursts of current passing through it. Example, a 15 amp branch circuit, 15 amp breaker with #14 awg copper wire connected to it, will easily pass short bursts of current well over its handle rating of 15 amps all day long. The breaker could care less what is causing the short spurts of current that is passing through it over its' 15 amp handle rating. It also could care less if the voltage at the receptacle feeding the preamp and amp is fluctuating up and down due to VD, voltage drop, caused by bursts of current placed on the #14 awg wire.

The power supplies of a preamp and power amp might though. Power amp's power supplies like its' mains voltage to be steady and not fluctuating with the beat of a high dynamic music source being fed through it.
.
Jim

As usual, Almarg nails it.

Using separate outlets, especially if they are on separate runs back to the breaker panel, will reduce the amount of amplifier-generated electrical noise that may couple back into the preamp. On the other hand, doing that may increase susceptibility to ground loop issues, including high frequency electrical noise as well as low frequency hum. If the connection between preamp and power amp is balanced, the likelihood of ground loop issues is considerably reduced.
02-09-15: Almarg

Hi Al,

The late Al Sekela, an EE, used to post on the AA Forum why decoupling the power supplies of audio equipment by using separate dedicated circuits benefited the SQ of audio equipment. Especially decoupling digital equipment from analog equipment.

As for ground loop problems I would say most ground loop problems caused from the use of multiple dedicated branch circuits is due to the choice of the materials and wiring methods used.

Worst wiring method is a single conduit run with multiple single current carrying conductors with insulated safety equipment grounding conductors pulled in the same conduit.

Dedicated branch circuits should never occupy the same conduit, or cable.

Best branch circuit wiring practices for dedicated branch circuits is the use of 2 wire with ground NM-B cable, (Romex is a Trade Name for NM-B cable), or 2 wire with ground MC Cable with an aluminum outer armor. The construction of the two cables cancels the EMF effect from inducing a voltage onto the safety equipment grounding conducting by the magnetic fields of the hot and neutral current carrying conductor caused by the connected load.

When Romex is used for moderate to long parallel runs of the cable they should be separated by at least 6 or 8 inches to prevent voltages from being induced from the hot and neutral current carrying conductors of one dedicated circuit onto others plus the safety equipment grounding conductors. Keeping them separated also, imo, helps prevent EMI/RFI noise transfer from one Romex cable to the other. Especially when one of the Romex cables will be used to power digital equipment.
Jim