RCA Signal Voltage Question

[ChevyBoy95]

If i measure the output AC voltage of my RCA's (probes on the left RCA) and get a reading of 1.986v. Does that mean my amplifier is getting 1.986v AC of input or 3.972v AC of input (L and R added)? Meaning if you measure 1 RCA's voltage, is the total ACV both added, or is it the amp only getting 1.986v AC collectively even though each RCA measures 1.986v?

To me it seems that it is getting 1.986v total, but just want to make sure.

[Skullz]

Only sees the voltage per channel, so if it is a 2v preout then the amp only sees 2v not the combination of the two channels voltage.

[Wicks]

I'm assuming you're talking about a mono amp?

On a 2/4ch amp, the channels are all separate. The input voltage from the RCA's is directly what the amp will see.

A quality mono amp should actively sum the input signals from your HU.

Here's a good link if you understand op-amps:

http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/opampvar5.html

If both input signals are in phase, then they will sum.

If they are 180 degrees out of phase then they'll sum to zero.

If the phase difference is in between 0 and 180 then you'll some combination of the two.

You can experiment with this by playing content into your amp and then pull one of the RCA plugs from the amp while leaving the other connected.

The amp's output should lower. I've noticed this on my DC5K when I had a flaky RCA connection behind my HU.

NOTE: Some HU's have "pico-fuses" on the ground connections of the RCA outputs and get grumpy when they are hot-swapped. Be careful of this before you try it.

So yes the internal circuitry of your amp "could" see 3.972V of input signal.

This is theoretical though and depends on many factors. Resistors of your op-amp summing circuit. Whether your amp has active summing or some sort of passive summing...etc, etc.

Do you have any concerns either way?