Nord User Forum

emielskey wrote:in the synth section when one selects Analog/Shape sine/Shape sine fold, the waveform is a bit corrupted in its pure sine form. I have to attach an oscilloscope to see the waveform, but it certainly isnt a perfect sine. higher up the keyboard it gets more pronounced. the rest of the "shape sine" waveforms sound as expected

I'm curious. Why did you go to the trouble of using a scope to check the " shape sine" waveform? Can you actually hear the effect of the anomaly?

StuartR wrote: I'm curious. Why did you go to the trouble of using a scope to check the " shape sine" waveform? Can you actually hear the effect of the anomaly?

sorry if I was unclear, I didn't use a scope, because you can clearly hear it. but when you hook up a scope, you can see what goes wrong. I am guessing it deprecates the waveform a bit to early so that when it jumps back again to the beginning of the period, you hear an artifact. but you can see it if you look at the wave output of the ns4. only I didn't look (yet)

i guessed wrong

you can see the imperfection in the bottom of the sine.
so this is Analog/Shape sine/Shape sine fold in the synth section.

no big issue and a bit nerdy, but it is definitely audible and fixable in programming

What does the spectrum of the wave look like?
You can compute that with Audacity.

Mr_-G- wrote:What does the spectrum of the wave look like?
You can compute that with Audacity.

fun, yeah I plotted it with SPAN from voxengo. here you go, the second is one of the other "shape sine" waves, they are all good sines in my ears, and the first pic is from the corrupted waveform "shape sine fold"
you can see a lot more harmonics. the 1st harmonic is is -33dB and that is really audible. whereas the "good" sinewave has the first harmonic at -104dB relative to the sine. that is really good for modelling synthesis. In the ideal world the sine has 0 harmonics.

(also fun fact: did record this at 96k on my UAD apollo, and you see that the noise floor of the converters of the apollo is not so good in the high freq range (above 20kHz))

. I was curious. My sine wave is sinusoidal!

Heatha05 wrote:

IMG_1029.jpeg

. I was curious. My sine wave is sinusoidal!

wow that looks like a perfect sine! did you select the "shape sine fold" waveform? As I mentioned, in my ns4, that one is the only bad one, the rest are also perfect sines.

I guess if you want a perfect sine, select the 'pure sine' waveform. Otherwise the folded sine does what I'd expect it to, just without the Osc Ctrl ever actually going to zero. Pics attached for info

emielskey wrote:(also fun fact: did record this at 96k on my UAD apollo, and you see that the noise floor of the converters of the apollo is not so good in the high freq range (above 20kHz))

A noise floor of -120dB is pretty damn okay at ANY frequency range.

Hi all,

I sold my NS3C and NLA1 and got me a Stage 4 Compact. Now I am discovering both the new possibilities and also some bugs and wishes for improvements (listed in the Google sheet):

Bugs:
- Vibrato is not in sync when using several synth layers at the same time (reported also here: nord-stage-forum-f3/stage-4-vibrato-sec ... 24402.html)
- When several synth layers are selected via "Section Edit", this group of layers is dissolved again the moment you press one of the three morph buttons in order to assign a morph source. So it's not possible to set a morph to a group of layers at once.

Request/wish:
- It would be great to have an "Impulse Morph" on the NS4 as well. This could be done, for example, using one of the pedals of the triple pedal.