Permanent LPF

[Ancodia]

This is possibly a dumb question, but I've never owned or even had the chance to play on a real 106, so I have to ask.

I've been comparing the demo versions of DCO-106 and TAL-U-No-LX, and I've found that with the controls in the same position (Best example is just the pulse wave, every fader down apart from the filter (EDIT: as in the VCF cutoff frequency) which is all the way up, and the volume so you can hear it) DCO-106 seems to still have an LPF on it that isn't present on the U-No. It's pretty clear in any scope view.

Is this some characteristic of the 106 that the U-No forgot? Or does the DCO-106's filter not open far enough?

[Steve W]

Are you using a program that shows frequency distribution? I just pulled my DCO-106 out, cranked the resonance on the VCF up to 100%, and played with the VCA's cutoff. I can see the resonance spike go all the way to 20 KHz, but with my hearing loss, it drops off between 3K and 4K. That said, it might be that the DCO-106 has a steeper roll off at higher frequencies. Might be nice to have an original to compare frequency graphs with different software versions.

Also, with the DCO-106's frequency slider, I can't hear the difference above about 82%, though I can see it.

[Ancodia]

Here's some screenshots for DCO-106:

DCO-106_settings.PNG (194.58 KiB) Viewed 13445 times

DCO-106_waveform.PNG (1.25 KiB) Viewed 13445 times

DCO-106_span.PNG (132.38 KiB) Viewed 13445 times

[Ancodia]

...and some for TAL-U-No-LX:

TAL-U-No-LX_settings.PNG (89.61 KiB) Viewed 13445 times

TAL-U-No-LX_waveform.PNG (1.15 KiB) Viewed 13445 times

TAL-U-No-LX_span.PNG (131.47 KiB) Viewed 13445 times

[huggermugger]

I compared TAL with Cherry's stock Oscillator, square waves on both. Almost identical, except for what I interpret as aliasing creeping in at the very top of the Cherry Osc, while TAL is super clean up at the top.

[huggermugger]

The DCO-106 image you showed doesn't just have the odd harmonics of a square wave, it's got even harmonics too, increasing in amplitude inversely to the normal harmonic series of a square. It's what happens when the duty cycle of the pulse isn't quite 50%. I can approximate it with TAL with the PWM slider set to 1.5.

But the front panel of your DCO-106 looks correct for a true 50% pulse wave, unless there's some modulation coming from somewhere or an offset. Unfortunately I don't own it to test it.

[Ancodia]

(Just realised looking at your TAL pic that I've not stated the versions, DCO-106 is version 1.2.0 (from the log file) and U-No-LX is 4.5.4. OS is Windows 10, DAW is ReNoise, although this happens running DCO-106 in standalone mode as well)

Interesting. I played around with the pulse width on DCO-106, and no position got rid of the curve on the leading edge of the wave in the scope view. Also, when I replicated your experiment with the U-No-LX, the wave was not similar, although the harmonics were. As for owning, I'm using VST3 demo versions of each.

Also, this happens with the saw and sub on DCO-106 too, neither of which is affected by the pulse width setting:

DCO-106_sub-waveform+span.PNG (241.61 KiB) Viewed 13404 times

DCO-106_saw-waveform+span.PNG (246.52 KiB) Viewed 13404 times