Yes, 6dB attenuation. I disagree with the other statement.
Ah yes, the pad is useful! 8) The name "L+R sum" may be a bit misleading though, as there's no "R" input to sum with.
You know how when you turn the volume up you hear a hiss, hum, or buzz coming out of your speaker? That's noise, and it's usually too quiet to hear (at least in the mix, and high-gain not withstanding). When you play your guitar and hear it coming out of a speaker, that's the signal. The Signal to Noise Ratio (SNR) is simply the ratio between how loud the signal is and how loud the noise is. The SNR is usually (always?) measured in dB, and higher numbers are better.what does "signal to noise" even mean"
My humbuckers tickle red but my tele with emgs never do.
Did you change the input impedance? This might load them down.
When using Front, you can still use rear Right, and therefore sum L (front) + R.
So the output should be set to L only when not running stereo? Jeez, I have to pound on my guitar to get red, but I've been running it Sum L+R... I'll have to try that when I get home.
Output settings shouldn't have anything to do with input levels/LEDs.
Re: which output mode to actually use if running mono, if you've built presets to be mono it almost doesn't matter. (Reverb or rotary will sound slightly different taking one side vs. a sum because they generate a stereo wet signal, so try & decide there.) Different stereo effects can cause issues with one output mode or the other. Inverting 1 channel (a.k.a. "phase reverse" in some blocks) of 2 identical channels will make that sound disappear with L+R sum. Not summing will cause one channel of things like ping-pong delay to be lost if you only take one output channel without summing. Even with stereo effects that sound okay summed, the apparent mix when summed will be lower if your dry sound was centered. So it's best to just monitor in mono and build mono presets if you plan to play in mono.
Perhaps that's the problem with mine. Mine definitely has a distinct effect on the sound. It appears to be an effect on the gain but maybe it's something else. But there is an apparent difference at 50 percent compared to 100 percent input level on my unit.
I run sum L+R using the front input