Dedicated circuits

One topic that doesn’t get discussed much is available voltage. The rule of thumb is that what voltage can’t accomplish, current will (I know I’m probably getting a bit technical here). So let’s take that USA goal of providing 120 volts at an AC outlet, and you are measuring or only providing 115 volts (this can sometimes take place during hot air conditioning days in your neighborhood or building). Your amplifier could in reality pull more amps on peaks (compared to providing it 120 volts), due to the fact that you’re providing a lower AC voltage to it. This is when voltage drop becomes part of the equation. I guarantee that in most situations this won’t ever be a problem, but it is something to consider, especially with longer runs of AC wiring to the outlet from the circuit breaker box (technically called load centers). Again, this is normally not a big concern in almost all installations, except for some, but at the same time, it is worth noting. Here are a few examples of voltage drop charts:

Cerrowire Voltage Drop Chart

Voltage Drop Chart

@dpop  okay, I can happily live with that!

If a train leaves New York travelling at 60 MPH, and a Hot Air Balloon can accend at a rate of 5 feet per second when the ambient air temp is 78.3 degrees, can I still hear any difference between a 12 gauge 15 amp line and a 10 gauge 20 amp line, when playing side two of Zappa's Burnt Weeney Sandwich LP?  Feel free to discuss ad nauseam.  🤣

thanks mike @ditusa 

Hey @dpop 

While you are correct that Watts = V * A, the way linear amps work (with the exception of Sanders' Magtech) is that the rail voltages WILL sag if the line voltage sags.  There's no adjustment feature without a voltage regulator such as a Furman with an AVR feature. 

Does this sagging matter?  Well, possibly.  I think this would be a good case study for Amir to do, to compare output linearity with input AC voltage on a linear amp. Due to the way current amplification works, and moderate amounts of feedback we normally pretend it doesn't.