What type of wire for dedicated 20A AC lines?

+1 What andybflo said. I’m laughing with you.

As an electrician and electronics technician(industrial controls) since 1979 there seems to be limited knowledge regarding the relationship between voltage and current flow(amperage) I=V/R and powerP=V*R. In the situation of voltage drop, lets consider a home that is 5000sq ft that’s 100x50 ft. The longest wire pull might be 120ft. Take the nameplate current draw (for the 120V supply) on any 150W integrated amp and plug those numbers into any of the voltage drop calculators available online and voltage drop is a non factor. It is also true that devices designed to plug into general purpose outlets cannot exceed 15amps.  also correct regarding . If someone’s system sounds better to them with larger wire then by all means enjoy.

poppsg

No connected load on the branch circuit and you measured a 5V VD on the end of line.

Yes. The lame ass electrician stripped the wire when pulled. The plaster & painter didn’t cover the boxes and the wire barely made connection is some places.

About 45 years ago my mother-in-law’s house barely escaped a fire when the same sh!tttily done aluminum wiring nearly set the receptacle alight.

Where was your reference point used for the measurement? At the electrical panel?

Where else?

What type of volt meter did you use?

calibrated Fluke.

I’ve been fixing wiring for my HiFi for 50 years. There are all kinds of idiotic claims being made. Few know that plain old Romex beats fancy wiring in a conduit. See Microsoft PowerPoint - Indy AES 2012 Seminar w-Notes v1-0.ppt (wordpress.com) by Bill Whitlock. The paper addresses N O I S E while audiophools prattle on about current which is a non-issue in a properly wired installation. We ran over two kilowatts of amp power on a single 20A breaker. Never blew once. Adding additional loop area is just plain  D U M B !

@poppsg , yes Ohm’s law absolutely comes into play here! I remember those formulas back from school; I really got into that stuff. I’m by no means an expert. I will call you on “It is also true that devices designed to plug into general purpose outlets cannot exceed 15amps.” which isn’t accurate when referring to momentary “peak current” or “instantaneous current” which can go up to 70A for milliseconds at a time. Again, I’m no expert, but I think this is pretty widely understood when it comes to amplifiers!

70A into 8Ω is 39.2KW. Ain't never gonna happen in a power amp.

200W into 8Ω is 5A @ 40V. Even a 3x peak is only going to draw about 5A from the line for a fraction of cycle.

2x200W amp might take from mains close to 1kW during peaks. The problem is that peak supply current won’t be expected 8A, but rather close to 40A. It is because current is drawn only for very short time (millisecond pulse) at the peak of full wave rectified sinewave. It applies to most of LPS. Power delivered with such short pulses not only creates larger voltage drops in house wiring, but also heat-up amp’s power transformer, that has to be oversized (higher copper losses and higher core losses for eddy currents and hysteresis).