Additional Piezo signal

  • Hi


    I will use a guitar with piezo bridge in the near future. Is it possible to send the signal of the magnetic pickups to the normal input of the Profiler to use effects and amps and additionally the piezo signal through a mono return in stomp X to use only reverb and delay for the acoustic sound at the same time? Because i don't want to buy another reverb and delay for the acoustic sound (maybe a compressor) and i would not need another channel on the mixer.
    Has anybody some expierence with this way of signal routing? I know, best way would be to buy a second profiler (maybe next year). ;)

  • If I'm not mistaken, the OP is talking about a guitar not dissimilar to this :
    http://www.fishman.com/fishman…ender-2/acoustasonic-tele
    The signal from this guitar can be mono, using a regular guitar cable, or stereo, where the magnetic pickup will be on the left channel and the piezo on the right, thus splitting the signal (though this requires a Y cable).


    I have one of these and never thought about using the FX loop for the piezo signal! I'll try this today and report back how it works. Great idea! Up until now, I've always had the piezo signal going out to a DI and direct to FOH. This method would be ideal for me.


    Cheers,
    Sam

  • Thanks for all the answers.
    The Profiler seems to be very flexible. The guitar signal is stereo and i have to use a Y cable to split mag and piezo. The idea is to fatten up the piezo signal a little bit by using a e.g. splitted neck humbucker through an normal amp and have both signals together for FOH. So i can play both signals through the Profiler. I think it's great to use another rig without loop for solos and switch back and forth. If i don't need a normal amp in a song, i would use the loop at the beginning of the signal chain and use an acoustic amp in the Profiler. Thousands of possibilities. :thumbsup: I love the Profiler.

  • I just tried this out, and unfortunately it would seem there's a bug in the software somewhere. With the mono loop set in the X or Mod slot, switching the stack on and off changes the HF of the piezo signal, effectively giving the sound the characteristic of playing through a cab when the stack is engaged, even with the mix at 100% (as though there was an extra cab sim at the end of the chain that was also being engaged). It basically negates the effect of the acoustic-sounding piezo. It's a real shame, as splitting the signal like this would have been ideal for me. More worryingly, it reveals that the X and Mod slots aren't actually 100% independent of the stack section, so any delays, reverbs, choruses or whatever you have looped and assigned to one of the slots will be coloured twice by the stack/cab sim (once as your signal goes past the stack and out of the Kemper's send, and then again once your signal returns from the loop and back into the Kemper before hitting the Delay and Reverb sections).


    Cheers,
    Sam

  • i'd guess that you would have phasing issues between the magnetic and piezo signal since both signals are coming out of your guitar in phase. both are converted to digital (we assume it takes the same amount of time delay). but the magnetic signal already got manipulated in the stomp and amp sections (which takes processing time) when it gets mixed with the piezo signal.

  • The point is though, is that they should be independent, depending on the position of the pickup selector on the guitar. When I select the piezo, no signal is being passed from the magnetic pickup, therefore the Stack shouldn't have any influence on the sound whatsoever when the mix in the loop is set to 100%


    Cheers,
    Sam

  • i def had split signals
    I used my BFR and sent guitar thru front and piezo thru back return


    BUT I cant get both signals! with MOD mono loop on I can switch but I can't get distored guitar to pass unless i turn the loop off


    can anyone help or upload a profile where they both pass thru?

  • Just set the mix value in the mono loop to 50%. Do me a favour though and try turning the stack on and off while playing on the piezo and listening for any variations in the high frequencies.


    Cheers,
    Sam


    ps I too had split signals, it was just that the stack section seems to still have influence on the sound of the piezo, even though it should be coming into the signal chain after the stack.

  • Forgive me if I'm wrong but it sounds like you want to do something the KPA isn't designed for, and that's to have a true and flexible stereo fx/amp section. To achieve your goal you would need to insert your piezo into the loop return of say the L section of the fx chain, then have this bypass the amp sim, and then your mag signal goes through the R section of the fx chain, through the amp sim, and then have these signals mixed back together for a mono output?


    A work around would be to take an output (monitor out or whatever), set this to send before the cab sim, then blend this back with an external mixer with the main out and then to whatever amplification you have, but that just defeats the purpose of simplifying things for you!

  • You're right in that the KPA isn't designed for this way of working, but in theory it is perfectly possible with its existing feature set, it's just that the feature doesn't quite work as it should.


    It's not about having a stereo section; that part of the original post is misleading. The guitar's output goes into a stereo jack, which is split into two mono jacks, one carrying the magnetic pickup signal, the other the piezo. From here it's only mono. The magnetic signal goes into the KPA as normal, the signal flowing through the stomps, then the stack, then the effects slots (X & Mod), the delay and reverb, and then out. The piezo signal joins the flow at either X or Mod, as the return in a Mono Loop stomp effect (note we're not sending any of the main signal through the loop). Setting the mix of this to 50% should mix the main signal path (the magnetic pickup) equally with the loop return (the piezo pickup), and then the player is free to select which signal plays by simply using the pickup selector on the guitar. Sounds great, right? The only problem being, the stack affects the Mono Loop stomp signal which is placed AFTER the stack section, meaning it shouldn't have any influence over it at all. Unfortunately with the stack engaged, it gives the effect of the piezo signal going through a guitar cab, attenuating the highs above 5-6K Hz, losing a lot of the acoustic-sounding properties.


    Cheers,
    Sam

  • I'm very new to the Kemper (total time = about half an hour!) so still getting my head around everything, so please bear with me :) I assumed the signal path was like a "normal" amp e.g. Stomp>Preamp>EQ>FX>Power amp>Cab. Now obviously there's no differentiation between preamp and power amp, so it would be Stomp>Amp>EQ>FX>Cab (hence my full stereo point), but are you saying it's actually Stomp>Amp>EQ>Cab>FX?


    I'm familiar with piezo/mag setups, I've converted a couple of PRSes with Graphtech Ghost systems (one trem and one wraparound bridge) but don't use them any more :)

  • The signal flows from left to right, if you're looking at the front panel of the KPA. Therefore, the guitar signal passes through stomps A-D, then in to the stack (amp, EQ, cab), then in to the effects section (X & Mod stomp slots, delay and then reverb). From here it's routed to the outputs. Don't forget, the stack section is an emulation, so the cab part is the KPA's approximation of the profiled cabinet's effect on the sound, as it doesn't profile each section (preamp, poweramp, cab) individually, but as a whole.


    Cheers,
    Sam