Upgrade Receptacle on 15A breaker

shouldn't a line with a 15A breaker go no higher than a 15A receptacle?

No, it should go no lower than a 15A receptacle.

Note that on a 20amp duplex the ground pin is horizontal and on a 15amp duplex it is vertical. There are some 20amp units that accept either configuration.

And there are also some pieces of gear that use a 20a IEC inlet.

Point being that a 15amp plug will not fit into a 20a duplex or IEC receptacle.

The reason is that the committee in charge of such things wanted to make sure that consumers could not plug in an under rated power cord.

As far as what's a good 15amp duplex; there is a range from the classic Porter Port to the latest from Oyaide and Furutech. Take a look at VH Audio for an idea of what's out there.

The following Wikipedia writeup may be of interest:

http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets

Note this statement: "In new residential construction since about 1992, a 20-amp receptacle with a T-slot for the neutral blade allows either 15-ampere parallel blade plugs or 20-ampere plugs to be used."

Regards,
-- Al

Soundbit,

You are correct......

If the overcurrent device, breaker, is a 15 amp then the branch circuit is a 15 amp branch circuit. Even if the branch circuit wire is #12 awg.

With that said according to NEC code, only a 15 amp receptacle can be installed on a 15 amp branch circuit.

You can install two or more 15 amp receptacles, (a duplex is two), on a 20 amp branch circuit per NEC.

Per NEC a 20 amp receptacle can only be installed on a 20 amp branch circuit.
The branch circuit breaker must be a 20 amp. And the branch circuit wire must be a minimum size of #12 awg, per NEC.

20 amp circuit breaker can be used only on a circuit that has receptacles. If the circuit has a mix of receptacles and light fixtures only a 15 amp breaker is permitted.