Electrical Question - dumb one - but a good one

You are talking about one manufacturer that has made some OEM receptacles, likely not Leviton, Pass & Seymour, Hubbell who make their own. I don't doubt you have experienced some differences in grip between some specific brand of receptacles. Unless you name a specific brand and grade, I can't comment further on that.

However, I stand by my original statement that 15A and 20A receptacles of the same brand and grade (by the well know manufacturers as those I named above) are identical in every way except for the face.

I've also tried most of the audio grade brands, and a couple of them have 15A receptacles that surpass other manufacturers' commercial and hospital grade 20A receptacles in terms of contact material thickness and grip. A good example is Furutech. Most manufacturers commercial/hospital, and audio grade contact material is 0.8mm, whereas the contact material in Furutech receptacles is 1.2mm.

Hubbell is a bit unusual actually, using contacts in their 15 amp receptacle that would not, in any way, accept a 20 amp male plug even if the faceplate of the receptacle had the T slot with at least a few of their models (Spec grade 5262/5362 and hospital grade 8200/8300 for example).

Contact surface area on the neutral side of the male plug (using a 15 amp male plug into the 15 amp receptacle) is increased by about 40% in this case, as opposed to using the "universal" contact allowing 15 or 20 amp males to be used.

So, in that case, there may actually be a disadvantage to using the 20 amp receptacle with a 15 amp male. I say may, because, if I remember correctly (just to totally confuse the issue), the Hubbell 8200H/8300H DO use a universal contact that will accept both 15 and 20 amp males if the T-slot is there.

The 8200H/8300H is a slim line, non plated contact hospital grade and my favorite in the Hubbell line up, although I do have in use (and experience with) the 5262/5362 and I'd say performance and grip are pretty close.

http://www.voodoocable.net/VAPA.htm

I'm not aware of any home amplifier that exceeds 15A draw but some come close, at least momentarily. That's one reason for monoblocks, but even those are usually built for the same 15A circuit. Yours might be the exception.

The VooDoo/Hubbell IG8300 is superior in the following ways: The ground terminal is isolated from the lead and neutral circuits to reject ground loop noise and electromagnetic interference.

What?!
.

What?!

LOL. Good catch, Jim.

I found the following explanation here:

A standard outlet connects the AC ground wire to the back strap, and thus to the metal wiring box. The steel framework of a large building may be at a slightly different potential than the AC ground. If the wiring box is attached to the steel framework, the ground loop thus created may carry large currents and upset the operation of sensitive equipment plugged in to that outlet.

An isolated-ground outlet keeps the outlet grounds attached only to the AC ground wire from the local service panel, and breaks the ground loop. The building wiring has to have another ground for the wiring box. This configuration is not something that should benefit a typical home audio system.

I'm sure some people use them to provide a separate earth connection for the audio system's AC. This is illegal and can be very dangerous. If the system AC earth connection is physically separated from the main power earth connection, a nearby lightning strike can cause brief offset voltages of several thousand volts between the two earth connection points. This is caused by very large currents flowing laterally through the earth.

This spike can flash over and destroy your equipment. Worse, it can set the remains on fire.

Regards,
-- Al