Pitch shifting bug?

[double-u]

So, only issue i've noticed so far is that oscillator 1's pitch will shift a couple octaves up randomly; haven't been able to solidly reproduce it, but it has happened a lot of times so far on totally initialized patches. I'm going to work on reproducing it.

Feedback?

[benjaminmatthews1982]

i may have found the same thing

here is a way i have figured out how to re-produce (assuming there is not something in this patch i am missing here -- which is obviously possible.  when i get more time i will re-produce from a new program)


find the patch "kraut funk" -- F4 - P102

listen to each layer by itself a bit to familiarize yourself

now,

enable stack a+b

play a "d2" -- assuming we 0 index things here (aka, the third d on the keyboard)

enable hold -- make sure you have got it modulating the the layer A osc1 pitch as it holds -- this seems to happen about 50% of the keystrokes on this patch -- you'll hear it go up and down and pitch

now go to "edit layer b"

disable all oscilators.  note how layer a's modulation has now stopped -- unless there is some way to route one layers modulation to another layer, (which is entirely possible -- im just learning this thing) that seems strange right?

it gets weirder though

note how it comes back but ONLY when layer B osc1 is set to "triangle" or "pulse" for shape -- it does not happen otherwise

and for the final stroke of weirdness,,

adjust osc1 frequencey -- note how layer a's pitch modulation only comes back when layer b osc1 frequency is ~G4-A5.  anything outside of that range, modulation stops. 

now, maybe this is some strange side effect and more is possible with this thing than i understand.  maybe layer b can modulate to layer a somehow?  maybe the oscilator shape and pitch matters for this said modulation? 

possible...but my guess is , this is something wonky /// potential bug.

-ben

[Bezoblika]

Could it be any way related to the pitch problems in the gated sequencer I found (info in the post on the 16th of June)?


Richard

[benjaminmatthews1982]

ok i got it to happen with a basic patch

here is the bug , should be able to be completely replicated

load a basic patch

make two layers,

layer A: any oscillator playing C2
layer B: ONLY triangle or Pulse oscillator , ONLY when frequency = G5  (a certain high range will cause issue - G5 being one of them)

make an LFO on layer B

set LFO to "osc all freq"

dial in the amount and frequency so you can hear it clearly modulating the pitch of layer B oscillator

notice how it is impacting layer a's oscilator about 50% of keystrokes

notice how this ONLY happens when layer B is set to "Triangle" or "pulse" for its oscillator and ONLY when osc1 freq on layer b is dialed in to higher pitches

i think it actually sounds pretty cool to hear layer a impacted by layer b like this-- maybe it has to do with some sort of hardware limitation , maybe its by design i have no idea, but just wanted to report this -- i dont mind it at all just was driving me crazy trying to figure out why my layer A was being impacted by Layer B sound only SOME of the time

seems like the gyst of it is, be careful layer up different oscillators at huge pitch differences -- one layer may start impacting the other which may not be the exact sound you were going for

[double-u]

Okay, this helped me reproduce what i've been noticing:

1) Initialize Basic Patch

2) Add Oscillator 2 as a Square Wave, 50% shape, C2

3) Oscillator Mix at 63 (50%)

4) Add LFO 1 to OscAllFreq

5) Increase LFO Amt and Frequency to 100%, then to 0%


The frequency will have shifted up on Oscillator 2 on some level but not exactly as if you did it from the parameter knob; when you change the parameter knob back to c2 it goes back to normal.


I've also experienced some other weird pitch shifting bugs, but this is reproducible

[cbmd]

Using the method described above, it sounds like what is occurring is the phase relationship of the oscillators changing.

You can verify this by setting the osc mix to min or max after turning the lfo amount down.  You should hear each oscillator at the correct pitch.

[double-u]

Using the method described above, it sounds like what is occurring is the phase relationship of the oscillators changing.

You can verify this by setting the osc mix to min or max after turning the lfo amount down.  You should hear each oscillator at the correct pitch.

makes sense,  i've still seen one of the oscillators jump randomly to different octave even shown on the parameter screen; but this isn't it.

[benjaminmatthews1982]

Using the method described above, it sounds like what is occurring is the phase relationship of the oscillators changing.

You can verify this by setting the osc mix to min or max after turning the lfo amount down.  You should hear each oscillator at the correct pitch.

ive messed a bit with osc min / max...no effect

i think ive narrowed down the weirdness to an even simpler test case to replicate -- i only require one layer, one oscilator, and one lfo now


step 1: blank patch
step 2: oscilator 1 - triangle wave - osc freq g5 (high pitch)

first weirdness : play a d2 (third d from the left) -- notice how randomly it will drop notes.  if you hold the note down when it drops, you will hear some very high harmonics , >5k but thats it.  compare this to playing a c1 (2nd c from the left).  that will consistently play every time (although admitedly once in a while with subtly different harmonics)

step 3: set an lfo - dest oscall freq - amount 74 - freq 43

play that same D2 again.. notice how most the time, it sounds distorted.  sometimes, it sounds correct and clean. 

i think when it plays inconsistently it can mess with oscilators on other layers (if we had more layers)

i actually dig the sound of the weirdness but it would be even cooler if it didnt mess with oscilators on other layers



please note this is all on os version 1.0.2


finally, to be fair, what i am describing isnt really a pitch shifting bug per say (although it can shift pitches of oscilators on alternate layers, if you have them) -- it seems to be more a general LFO issue with certain pitch ranges on triangle / pulse wave oscilators.  maybe should split this one into a different thread -- didnt mean to hijack double-u's as i think that might be a distinctly different issue.

[benjaminmatthews1982]

more isolation:

if i pick either triangle or pulse wave (either oscilator), and just set osc freq to g5, it distorts or gets strange about 50% of the time.  no need for any other modifications.

i'm starting to wonder if i have a hardware issue -- going to contact tech support.

[MDMA]

I've tried replicating your settings and don't get anything the way you describe.

I do get a ever so duller tone on every eighth and then fourth note at very high frequencies, but I put that down to them being analogue oscillators, it happens with my other analogue gear too.

Sounds like you have a problem for tech support.

[Troy92Evans]

This pitch shifting bug is the biggest problem I'm having also. It happens often enough that I'm pretty concerned about it happening during my gig later. Mine isn't always octaves either so it's pretty brutal.

[benjaminmatthews1982]

I've tried replicating your settings and don't get anything the way you describe.

I do get a ever so duller tone on every eighth and then fourth note at very high frequencies, but I put that down to them being analogue oscillators, it happens with my other analogue gear too.

Sounds like you have a problem for tech support.

thanks a bunch for helping me test this!  i've emailed tech support so we'll see what they say

mine is about half the played tones, and its not just dull -- its extremely distorted, and / or near silent. 

[benjaminmatthews1982]

As info I was able to fix my issue via global -> calibrate

I feel really stupid for not trying that first on my own before emailing tech support!

Anyhow if any of you are experiencing something similar make sure you try it out!  Happy to say there is nothing wrong with my unit.

[Gerry Havinga]

As info I was able to fix my issue via global -> calibrate

I feel really stupid for not trying that first on my own before emailing tech support!

Anyhow if any of you are experiencing something similar make sure you try it out!  Happy to say there is nothing wrong with my unit.

Well done Benjamin, this goes with the territory when debugging. I really appreciate you posting the answer, please don't feel sorry.