Hi Everyone,
This morning I decided to play with phase cancellation on the DT.
Here’s the basic challenge.
Using 2 tracks, make 2 sounds that cancel each other to silence.
Why? Because once you can do this, you can make very small changes to either sound and get cool phasing effects.
Best technique I have found so far is using single cycle waves, and then using micro-timing to start them out of phase. Any other ideas?
Best regards,
Gino
Since I have no Digitakt I cannot say for sure if the following works on it, but this may give you much finer control over the shift than microtiming and as additional bonus you can modulate it with an LFO:
If a single cycle has the minimum length of 120 you can shift sample accurate.
I don’t know about single cycle waveforms but for samples (for anyone who’s interested), all you need to do is use two samples and adjusting the start time of one by a small amount will give good results.
You can also modulate the start point of one with a low LFO depth, that’ll work too.
That is great! Thank you!
The reason for single cycle waveforms is that they are loopable without clicks (starting at 0 and ending at 0).
And if you use a sample which contain 2 cycles you can still move the start point without hearing clicks when looping (when length is set to the length of a single cycle).
Completely useless with a DT, but that’s how you used to simulate hi-pass filters on old hardware samplers which only had lo-pass filters: layer 2 samples, one being an inverted copy of the other. Then apply lo-pass to one sample … There you have it, phase-cancelling of the bass equals hi-pass.
Ok. Makes sense
Mind = blown. Makes sense but never thought about it.
I guess the trajectory of the curve should also be maintained. Just connecting start- and endpoint at the same value might not be enough. For example the green curve vs. red curve in this pic:
Of course. I just left it out, because I see the “continuously differentiable” requirement as part of a valid “complete cycle”.
(and I don’t wanted to throw math terms around or write a complete article about what qualifies as valid cycle)
Cool cool, I just thought I’d mention that since you were talking about “loopable without clicks”. A complete cycle can be pretty much anything, it’s mostly the clicks on otherwise smooth sounds I was thinking about.
Oh man! I was super excited to share a breakthrough, but it didn’t work 
Rather that buy one of these:
I made my own reverse polarity cable by reversing the tip and ring connections.
Then I was going to sample from the Digitakt to itself with the cable, but the DT detects it and won’t work.
Well, maybe it was a good thing, because I don’t want to hurt my prized DT! 
But I really wanted to do this DAWless, and I ended up using my DAW to invert waves and use Transfer to get them to the DT.
The good news is that I’m getting great results now, and it’s cool to hear things like bit crushing with cancellation. It’s not 100% silent, but very very good. Overall I’m impressed with the accuracy and diversity of the DT, as it can sound both warm, and digitally cold when needed.
I know, no one is looking for yet another feature request, but it would be cool to be able to do this trick without using a computer. Maybe someone will figure it out.
Best regards,
Gino
Yes, that’s a really solid technique for phasing. I did some “dual cycle” waves, and it works great on the DT.
And the LFO works nicely to get automated phasing effects.
The missing part is getting the polarity reversed for one of the samples. When they both play at the same time it should be almost silent.
Best regards,
Gino
That’s a great point. If you just want phasing, that’s the tried and true technique.
I often ask myself if it’s worth the extra effort to get complete +/- polarity cancelling just to get very similar results. Sometimes the direct way (what your sharing) is best.
Best regards,
Gino
Maybe you could do this with a standard Mono TS cable and an audio transformer 1:1 inbetween. Switching pins on the output of the transformer should invert the phase, without any funny business from the DT detecting something dangerous haha.
But it might not turn out to be the completely accurate inversion of the sample, with the transformer‘s sound characteristics and everything.
And if you want to involve a power supply, a simple inverting amp circuit should definitely work. Takes some more cabling though.
Edit: Actually, what is happening in the DT when you try and record something with your cable?
The product image shows a TRS cable. When this is used with a balanced mono signal you can reverse the phase by switching tip and ring.
Your image shows a TS cable (no ring). You wrote you switched tip and ring, but there is no ring (the small ring-like thing is an isolator and carries no signal). What you did is switching ring and sleeve. The sleeve carries (common) ground. So you effectively short-circuited the audio signal by switching the contacts.
Digitakt does no magical detection here. You just tried to sample ground which should result (after auto-normalization) in a noise sample.
Yeah, if it was a small gadget, it would still count as DAWless 
Regarding what I get - It’s white noise, which is the same if you force it to record an input that has nothing coming in.
Best regards,
Gino
You definitely know this technique!
Using polarity/phase cancellation to invert filters is way cool.
Best regards,
Gino
Haha, you are right. And here I thought I knew how this stuff works
