OSC 2 has significant problem

PS-20 is an ultra-realistic, polyphonic, hot-rodded tribute to Korg's renowned MS-20.
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sekim
Posts: 24
Joined: Sun Dec 11, 2022 1:01 am

OSC 2 has significant problem

Post by sekim »

I discovered that OSC 2 on the PS-20 current build has a significant issue. OSC 1 is fine. Both the saw and the pulse waveform settings cause, for lack of a better way to describe it, a "plosive" upon both starting and stopping. Its difficult to determine whether its the VCA, but since the problem does not exhibit on OSC 1, I sort of doubt it. Below are several screen shots of oscilloscope that show the issue. The synth is in init state with everything off but the OSC being examined. EG2 has everything twisted full ccw except Sustain which is full cw. All settings the same for all images below except the wave form.

On the pulse waveform it is even weirder, at 50% its just fine, but gets progressively worse as the knob is twisted to the max 95%. Its a real problem using unison since each of the voices has the "plosive" and they add together. For example a pulse at 95% in unison using 16 voices is almost impossible to prevent output clip. Bottom line is the issue is manageable until using OSC 2 in unison (even with less voices), then things go south in a hurry. I really like this synth other than this bug, please fix. :)
Attachments
Osc2 saw plosive.GIF
Osc2 saw plosive.GIF (51.56 KiB) Viewed 5758 times
Osc2 95%pulse plosive.GIF
Osc2 95%pulse plosive.GIF (38.62 KiB) Viewed 5758 times
Osc2 50%pulse clean.GIF
Osc2 50%pulse clean.GIF (58.57 KiB) Viewed 5758 times
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cherryaudio Greg
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Posts: 854
Joined: Wed Aug 29, 2018 5:06 pm

Re: OSC 2 has significant problem

Post by cherryaudio Greg »

Hi,

Please contact tech support, and let them know the steps to duplicate the problem: https://cherryaudio.kayako.com/conversation/new

If the problem is happening with a custom preset, you could attach that to the support request as an example.

Greg
sekim
Posts: 24
Joined: Sun Dec 11, 2022 1:01 am

Re: OSC 2 has significant problem

Post by sekim »

Done. The issue is preset agnostic with the caveat that OSC 2 is in use and set to either saw or pulse greater than 50%. As mentioned earlier and in my post for tech support, the problem is not present when pulse is 50% but gets progressively worse up to the max PW of 95%. Let me know if anyone needs more info or help testing a fix. Also, I included an "init" preset for them to use to hopefully make it a little simpler to recreate the steps I gave them.
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