Elektron-Users

i made a dumb post

Nevermind.

I have a Monomachine Mk II running OS 1.31b.

I've been playing with the GND>SIN machine a lot and noticed a problem with individual note volumes. Just wanted to post to see if anyone else has run across this with any of the machines.

Start with an empty kit. Put a trig on step 1 of machine 1. Adjust the Hold to a high enough value so you can hear a sustained sine tone. Now adjust the note number by octaves (hold trig, hold Function, use right/left arrows). I started with C 0 and went up through C 8. Some of the octaves would drop in volume by 1/2 or more, just by changing the note number.

Once the volume dropped I had to play around with removing the trigger, putting it back and/or changing note number by a few semi-tones to get the volume back. Interestingly, it was not consistent. A different track or different trigger would give different results across the octaves.

This is really noticeable when you put a trigger on step 1 of track 1 and track 2. You would expect to hear a volume increase (adding sine waves in phase), but sometimes the volume would drop real low as I shifted both note numbers through the octaves.

oldgearguy wrote:
I have a Monomachine Mk II running OS 1.31b.

I've been playing with the GND>SIN machine a lot and noticed a problem with individual note volumes. Just wanted to post to see if anyone else has run across this with any of the machines.

Start with an empty kit. Put a trig on step 1 of machine 1. Adjust the Hold to a high enough value so you can hear a sustained sine tone. Now adjust the note number by octaves (hold trig, hold Function, use right/left arrows). I started with C 0 and went up through C 8. Some of the octaves would drop in volume by 1/2 or more, just by changing the note number.

Once the volume dropped I had to play around with removing the trigger, putting it back and/or changing note number by a few semi-tones to get the volume back. Interestingly, it was not consistent. A different track or different trigger would give different results across the octaves.

This is really noticeable when you put a trigger on step 1 of track 1 and track 2. You would expect to hear a volume increase (adding sine waves in phase), but sometimes the volume would drop real low as I shifted both note numbers through the octaves.

Did you check your filter/keytracking settings? Make sure it's wide open so you don't affect the sinewave amplitude.

Thanks for the suggestion but I thought filters don't affect sine waves. I also thought that if I initialize the kit and clear the patterns, I get the defaults (everything open/normal).

Since the only thing I changed was adding a trigger and then modifying the note value, I thought I eliminated the other variables. If the filters were an influence, I would expect to see a regular decrease as I shifted up the octaves. In fact, that is not what I was seeing.

Fillters will affect the amplitude of a sinewave in the vicinity of the cutoff and according to the dropoff slope - so as you're increasing the pitch, or note value, near the cutoff freq you will hear the dropoff in amplitudes. Think of it this way, as you increase your sinewave frequency you are tracing the frequency response of the filter, which is constant prior to the cutoff and then drops off at: 12dB? 24dB? etc per octave.

It was just something to check in your case.

I'll doublecheck my tests, but if that is true, I would see (for example) full amplitude at C0, C1, C2, C3, start to drop off at C4, even lower at C5, etc.

What I saw was an inconsistent behavior - C5 full amplitude, C6 lower, C7 full amplitude, C3 low, and if I re-ran the tests, I'd get a different spread and I only touched the Hold parameter, nothing else (well, base note pitch, but you know what I mean).

Yeah that definitely sounds off. I'll try it later and see if I get the same behaviour as you.

OK - now that I'm home and reading my notes, it is clear that the problem is most evident with 2 tracks, same note, same trigger on both tracks. My measurements with just 1 track showed some variation, but not much compared to the large swings evident with 2 tracks.

One theory is that the absolute phase of the sine wave is not always 0. If the phase of a sine wave varied at the time the trigger was enabled, that could explain the semi-random volume variations when mixing 2 sine waves.

Most of the time, it seems the phase is the same, but once in a while it seems to shift and cause some cancellation resulting in a volume loss. So, when I submit this to Elektron, I'll probably word it as a question more so than a bug.

I think it's been established on a thread in here somewhere that the phase doesn't reset for each note, so you're probably right.