Phase issues with sampler

[arcy]

Hi guys, I'm making a synth sampled from my analog synth.
I recorded 3 RR with an interval of third. So I have a bunch of different samples with a natural inconstant pitch.
I edited each sample in the sampler editor applying a loop to sustain notes.
My sampler is under a Synthesizer Group in order to spread more voices with unison.
But unison makes phase issues.
I tried to modulate the SampleStartMod for each sample in each RR group like this:

but I still have phase issues.

How could I fix it?

Thanks!

[Lindon]

@arcy are your samples phase aligned? - start by making sure they all begin at the same time.

[arcy]

@Lindon they were equally cropped from the daw...I sampled with midi notes perfectly in grid..

[Lindon]

@arcy said in Phase issues with sampler:

@Lindon they were equally cropped from the daw...I sampled with midi notes perfectly in grid..

thats not quite the same thing tho is it...they might be aligned - they might not...open them in your audio editor - zoom in and compare....

[arcy]

@Lindon I'm not sure about it...I zoomed in and I did not find misalignments...I also tried to invert the phase but still...it's not a multi-mic recording, it's a mono synth that I sampled like a piano, playing one note at a time with the same note length. Phase issues appear when I play octaves (ex. A1 and A2) or when I add more than 4 voices in the unison knob...

[d.healey]

@arcy I you sure it's phasing and not comb filtering you are hearing? Phasing sounds like a swooshing, comb filtering is where you get constructive and destructive interference caused by the waveforms cancelling or attenuating each other.

[arcy]

@d-healey if can be useful, this effect disappear when I change pitch by some cents on a single note key...

[arcy]

@d-healey no it not seems a comb filter like sound...it's more like a phaser effect active..

[Orvillain]

Does your source synth definitely reset the phase of the oscillator when triggered from a midi note? Because if it doesn't, then that would cause your samples to most likely not be phase aligned.

[arcy]

@Orvillain thanks for your response. My Nanomodules ONA has a sync input. I tried to trigger it with the gate cv and re-record the samples, but I always get phase issues with octaves.....

[arcy]

Ok, I found the problem. Due to the imperfect tuning of an analogue OSC, the phase was not aligned. So, I perfectly tuned all my samples and manually phase-aligned them. Now the phase effect when two notes were played in octaves is gone.
Thanks for your support! I'm sure that this info will be useful for other samplists.