Filter 1 as oscillator? Not really

0x80 · 2014-12-28T22:34:37.000Z

TRK (Filter1 Keytrack) lets the cutoff frequency follow the pitch of the sound played. A setting of 32 will make the filter track the oscillator frequency in note intervals, making it possible to play the Filter 1 resonance the same way as an oscillator is played.

I’ve tested this on two devices (A4 and AK) and this doesn’t seem to be true for filter 1. Filter 2 tracks the pitch correctly (afaikt), but filter 1 is really off especially in the lower regions. It can barely do 1 octave correctly, so it is not really possible to play the filter as a sine-wave oscillator.

Try turning down the oscillators and put the resonance to max for filter one and set the tracking to 32.

Playing filter 2 as an oscillator gives some really nice results also in combination with filter 1 and the regular oscillators I only wish filter 1 could track as good. O well.

avantronica · 2014-12-29T11:12:51.000Z

I am convinced that this was usable before on filter one. Currently it is not, to even cover one octave i need to crank keytrack up to around 37, beyond that, even at 32 it is not even remotely close, whereas filter two is fine and usable as described. So either something has changed under the hood or my memory is failing me, but either way, the manual is currently misleading, so something needs to change (firmware/manual)

0x80 · 2014-12-29T13:51:59.000Z

I really hope your memory is correct and that they can fix this in the firmware!

I was expecting maybe filter one tracking would be unstable by design, but now I think of it that doesn’t make much sense in a modern device that controls every other parameter so accurately and fast.

avantronica · 2014-12-29T15:41:03.000Z

I’ve asked Elektron, will report back, hopefully someone may kick in with confirmation of an old patch that no longer works or recollections that it never did track nicely, in which case the manual is misleading us (at least with regard to accurate self oscillation) #A4bug #A4lim ??

hafilax · 2015-01-07T01:54:19.000Z

I made a patch using filter 1 resonance and my recollection is that it didn’t track beyond an octave and that it actually changed tuning between uses. I also recall that turning up one of the oscillators locked it in without changing the sound much.

subq · 2015-01-07T05:02:28.000Z

hmmm…just seeing this thread, I may need to go back and check some patches because I’ve made some that rely on tracking (i.e. sine wave “like”…just with filter resonance)

hafilax · 2015-01-09T21:47:02.000Z

I played around a bit more with the filter as oscillator this morning. Both filters track over about 2 octaves. The filter tracking is not fine adjustable; you can hear the step between 32 and 33. I wonder if the calibration routine adjusts this or if the algorithm could be improved?

My other discovery is that I couldn’t get portamento or note slides to work with the resonance sounds. Even tried parameter slides which didn’t work either.

clunky · 2015-01-10T13:41:23.000Z

""hafilax"":

I played around a bit more with the filter as oscillator this morning. Both filters track over about 2 octaves. The filter tracking is not fine adjustable; you can hear the step between 32 and 33. I wonder if the calibration routine adjusts this or if the algorithm could be improved?

My other discovery is that I couldn’t get portamento or note slides to work with the resonance sounds. Even tried parameter slides which didn’t work either.

not sure what you’re doing but portamento works on the oscillators not on a resonating filter acting as an oscillator.

hafilax · 2015-01-10T19:25:53.000Z

""clunky"":

[quote=“hafilax”]I played around a bit more with the filter as oscillator this morning. Both filters track over about 2 octaves. The filter tracking is not fine adjustable; you can hear the step between 32 and 33. I wonder if the calibration routine adjusts this or if the algorithm could be improved?

My other discovery is that I couldn’t get portamento or note slides to work with the resonance sounds. Even tried parameter slides which didn’t work either.

not sure what you’re doing but portamento works on the oscillators not on a resonating filter acting as an oscillator.

[/quote]
I was trying to I was trying to see what the filter tracking actually tracks and what the internal logistics are. In an analog synth the pitch would be a control voltage and the filter tracking would depend on this. The filter would then follow potamento etc.
IMO the potamento and note slide implementation is a little messed up. I turned tracking off on the oscillator and made a sequence with the filter moving around. Kind of like throat singing with harmonics excited over a drone. I then wanted note glides but the filter notes were always stepped. What ended up happening were bends in the drone note which I really didn’t expect with the note tracking turned off.

frufrufron · 2015-02-28T20:37:05.000Z

I also dream of this feature

Cutoff-keytracking with consideration of portamento and pitchbend is very pleasant to hear when playing mono leads/bassline with high resonance

A lot of other analog synths do this…

Maybe in a future update?

About the same subject:
http://www.elektronauts.com/t/feature-request-additional-portamento-options/6903

snowcrash · 2015-02-28T21:07:45.000Z

Yes, practically all vintage synths do this, because the portamento slew was on the keyboard CV and not the VCF’s CV-in!

AdamJay · 2015-04-14T16:24:17.000Z

So do we think this got changed (for the worse) in an update?

Reading this thread now and it sounds like this is what happened to one of my kits sounding noticeable different on a high resonance filtered stab track after the last update.

Well at least I have a better idea of where to go in the patch to get it closer to how it sounded originally.

sezare56 · 2018-05-24T07:43:38.582Z

My filter 1 tracking is wrong, even with one octave range. Is it worth to do a calibration ?
My A4’s right Keytrack setting is between 34/35 instead of 32.

avantronica · 2018-05-24T08:43:33.898Z

sezare56:

setting is between 34/35

Same here and I would have calibrated lots prior to this post - afaicr it’s not mentioned in the manual, perhaps because keytrack is simply approximate (though decent for variable filter)

sezare56 · 2018-05-24T08:53:18.334Z

So you mean it’s not sure that calibration would improve that ?

avantronica · 2018-05-24T09:02:38.831Z

yeah, that’s what I meant - but why not calibrate anyway, okay it suggests not to in the manual iirc, but it is an option for the curious/adventurous

if you do, I’d be interested to learn if the calibration affects the cv side, I don’t believe it does, but I have significant divergence between A/B and C/D for pitch stuff

it would be nice to hear from any MK2 users as to whether the lowpass keytrack is different and usable for a resonating filter at the 32 setting

sezare56 · 2018-05-24T09:19:46.639Z

avantronica:

it suggests not to in the manual iirc, but it is an option for the curious/adventurous

I’m quite curious/adventurous with gear mod, but I would be sad to get worse tuning after. Any bad experiences ?

I think I can’t really test CV calibration, as I’m new to it, and my only reference would be a modded Monotron, uncalibrated with 1 pot and resistors on a breadboard for pitch scaling !

avantronica · 2018-05-24T09:47:57.557Z

I think you’d best get the official reason from support as to why user calibration isn’t recommended in the manual - it’s unlikely to be a big deal imho, but perhaps they are fine tuned at assembly for optimum settings, this is presumably better than the automated calibration, but that’s a guess, I’ve calibrated both analogs and had no issues (required for AR OS update in any case) … as ever, ymmv ! However, I doubt it’s going to address the filter 1 issue, so I wouldn’t do so purely on that basis … then again, why not (if curious enough) … do it for science

sezare56 · 2018-05-24T20:30:18.314Z

avantronica:

why not (if curious enough) … do it for science

Calibration done for Science of Curiosity !
It really improved filter 1 Keytrack.
Correct results at 32. Not perfect, but really better. I hope it will last.