Wow, found a weird bug... polyphony problem with kemper (all high gain profiles) - (SOLVED - I am a noob)

PoMerizzi · Apr 29th 2013

I first thought it was only related to one profile... but it happens with all of them (high gain and medium gain profiles).

I have this solo to record where I play this minor sixth interval (both notes at the same time). Here's the exact thing so people can try it out...

1) play 12 fret on the b string and 15 fret on the E string...

let both notes ring

Now you will hear a really nasty and clear low Ab harmony (like 5th string 11 fret) ringing really loud. Looks like the Kemper is having a hard time with polyphony ;o) Anyway weird.. just my thought. Make it impossible to record the solo without this artifact (had to remove it with melodyne... not cool).

Try it people and tell me if you get the same thing

paults · Apr 29th 2013

I'm several hours away from being able to try it at the moment, but:

Are you getting it with more than one guitar? If so:

How hot are your pickups? What are your clean and distortion sense settings?

Can you give us a specific example of a rig or two?

gorillabendz · Apr 29th 2013

Interesting ... do you have the harmonizer enabled?

DonPetersen · Apr 29th 2013

Hi PoMerizzi,

I can't produce anything that remotely resembles what you describe.
Single coil pickups that get too close to the strings have been known to produce all kind of weird artifacts, but that is a setup issue that would also be present in a tube amp.

can you send me a recording of what is happening?
pm me, please.

thanks.

PoMerizzi · Apr 29th 2013

Allright, I will do a record of it so you can hear what I'm talking about.. asked my friend who also got a kemper, he doesn't seem to have the problem.

Trazan · Apr 29th 2013

If you bend the B upwards, this low ghost note moves in the opposite direction...?

I would think this is just intermodulation, as you will get from "real" amps too, but hard to say without knowing more.

PoMerizzi · Apr 29th 2013

Here's a sample so everyone can hear it and tell me if I'm going nuts

https://soundcloud.com/po-m-rizzi/kemper-problem

there I play a sixth, and you can clearly hear a really low note appearing (harmonic) when I let both note ring together, If I move the chord it still does it... tried with 4 guitars, different profiles, same problem

I may be nuts

paults · Apr 29th 2013

Does your friend live close enough to try his Kemper with your guitar?

If you unplug the guitar, and play with your ear up against the body, are those low overtones there?

Trazan · Apr 29th 2013

The nature of the beast! It's not the Kemper.

Two frequencies making new frequencies that are the sum and difference of the two. Creates that ring modulator thingy

burningyen · Apr 29th 2013

Yep, simple harmonic intermodulation:

B = 493.88Hz
G = 783.99Hz
G - B = 783.99Hz - 493.88Hz = 290.11Hz = ~D

Which is the ghost note that I'm hearing.

PoMerizzi · Apr 30th 2013

god I feel dumb... since I was working tonight in a music store, I tested some amps (tube, non-tube), they all do it. Lol. Guess I have to get used to it. Ring modulation eh? lol. Now I feel dumb . Thanks for the info

viabcroce · Apr 30th 2013

Glad the old Toaster is healthy

What about editing the thread's title? Would be nice IMO

paults · Apr 30th 2013

Once you hear something like that, you notice it for awhile. But, as soon as the novelty of it wears off, it will be as unheard as the squeak of the kick drum in "Since I Been Loving You", "Superstition", "Needles and Pins", and so many more....

Share