HELP, got a show Saturday need to figure this out.

REALLY need some HELP! Bad!

Gear Facts:
Les Paul>>>>>>KPA PowerRack>>>>>> Mesa 4x12, no outboard gear, real straight forward.

The Live stage plan that should have worked:
#1 Run 4x12 backline by powered Kemper so both the band and I have some stage levels. #2 give sound guy left main out and let him do his thing (mono live PA, so no need for stereo outs, so yes, again very simply "Mr. Sound Guy, here is your XLR left main out from my KPA... have fun with it. Mr. Soundguy was like "cool man". Done deal.

Now, for what actually happened that night...
During sound check everything was cool, 4x12 sound was good, midi switching working KPA doing great. I'm noodling around on sound check like we all do and "boom" sound guy starts bringing up stage monitors that my guitar is in the mix and I instantly have an obnoxious ridiculous 1 second or longer "echo" going on that should in no way be there. I know what your thinking... No I do not have effects on this setting, it was a dry stack only. So I start focusing on this problem and trouble shooting. I pick a single note on my guitar and wait and listen, right? (that's what you would do). Here is what was actually happening. I pick the note and my 4x12 is sounding that note perfectly (you know, accurate with no latency) THEN!!!!! One second later that same note comes through the monitor mix. I am getting a ridiculous bounce! So, of course it HAS TO BE THE SOUND GUYS FAULT, RIGHT???? OF COURSE IT IS LOL!!!! "YO, Soundguy fix your latency delay thing you got going on there buddy !!!" He goes scrambling, can't find anything causing it on his end, but is hearing the problem. We both agree " let's unplug the KPA left main out and just mic my cabinet. So, we did... BAM!!!! problem solved. Whole issue went away instantly. I apologized to the sound guy and recognized the issue was on my end, not his. The show went on, rig still sounded good using the KPA and just micing the cab, but I did not get to experience letting the KPA running direct to FOH.

Any ideas on why I have a ridiculous very pronounced delay between two outputs on my KPA? I have not a clue and I'm sure it's a setting somewhere / operator error issue. I have a show this Saturday night and would sure like to have this resolved before hand.

Any help comments are greatly appreciated.

Great feedback, so I have an old trace elliot acoustic amp with an XLR input (so you could sing and play your acoustic at the same time) that will be perfect to simulate my at home version of a live PA system.

I'm going to check into what everyone said and see if I can recreate this here tonight, I'll be in touch shorlty.

We will see if that bounce is still there.

Well, that was quick, and yes it's there! The problem is for sure mine... Now I just have to figure out what the hell I did wrong! LOL!!!

In all honesty I always just wanted to play guitar, computer programming was never my thing. When VCR's were around and you had your clock on them, my time was never right, it always blinked 12:00 or something... yeah I'm that guy!

SOMBROX, you nailed it!!!! My main output is set for delay/reverb wet. (while the hell that happened, I don't know, but that is what's causing the issue... when I pick some other settings there latency goes away both monitor and PA are in harmony together as one, like it should be.

So.... Next question...

with all these options Kemper gives you, what should I really have that set to. Most my soundguys around town run their amps bridged to get the best bang for there dollar and are really running mono PA systems (it's pointless to hand them 2 XLR's and tell them left and right) So, agreeing that point and knowing I will hand them 1 XLR from my left main "what should I set this output to?

The many many choices Kemper provides us are... Please VOTE!
GIT + processing
GIT studio
STACK
MOD LEFT
MOD mono
MOD stereo
MASTER left
Master mono
Master stereo
Delay/reverb wet (Yeah, we know all about that now don't we )

While we are figuring this out, just in case someone else does the same dumb thing I did and needs to read this later I want to point out...

While I am at home playing this rig (essentially my exact live rig which is awesome) I did not hear these issues. I plug my Power Rack KPA into a couple 2-12's that sit in my office at home in place of the road cased 4x12. I point this out because I have been rehearsing with great tones, no strange delays, using my same switching (maybe with house slippers and not combat boots LOL) and I would not have noticed this issue at all until handing the soundguy the XLR at the show (which is always a way too late time to deal with $%$#% as we know)

Moral of the story, if you gig and use the KPA and are new to the KPA like I am, it may be wise to set up the "fake PA" (another amp) at home like our great community suggested I do before walking on stage going full rockstar. It may expose some problems you are totally unaware of. Had I done this, I would not have had this misfortune.

thanks guys! I really do appreciate it. We all know that nervous sweat panic on stage when crap isn't working.... I HATE THAT FEELING!!!

thanks again, and please vote on output selection if you don't mind.

Master left is working great for me. Everything coming out of the monitor cab appears mirrored perfectly for FOH and in sync which is what I want.

You folks are awesome!! Thank you everyone who commented. That was a 24 hour turn around time. Everyone had great ideas ( create a fake PA, check output section, and my all time favorite hate on the sound guy some more ) and we put them all together and problem solved! The show will go on this Saturday and with FOH DIRECT, cant' wait!! I'm excited.

PS: you know I just backed up after that change and saved that puppy to my thumb drive and put it in my guitar case. I'm learning

Great forum community.

Quote from Ingolf

If you had for example a ping pong Delay running you would only hear one side of the delay when running Master left.
With Master Mono both sides will be summed.

Ya, know.. your comment makes for a good argument to actually use Master Mono. If you know your are handing over a single XLR to a sound guy that for sure has a mono PA system as many of them actually do which I know is contrary to popular belief of everything is always stereo. I play small bars and clubs and we see mono PA all the time. I personally don't use many effects (maybe a reverb at best) in the KPA for what I do, but if I decided to use lots of effects, I would want to hear "all of the effect, not half of it" making a good argument for Master Mono as the best output setting. Very interesting comment on Mono Master. Confused? Yeah I am too. LOL! (remember the good old days when all we had to do is plug in a speaker cable from a tube amp head to a 4x12 and make sure impedance was correct... do I miss those days? Maybe.... )