Bug in VM900 901ABB module

[martin_l]

It seems there might be a problem with the 901ABB oscillator module. When using the 'Low' setting in one of the B-modules, which then is connected to modulate some other module (i.e. frequency modulate another 901) and then frequency on the oscillator driver is set very low, depending on the audio buffer size sooner or later the required CPU is increasing and the output starts to stutter. Might it be possible that at very low frequencies, there are getting denormal issues, which are driving the CPU load up?

Cheers,
Martin

[MRBarton]

Hi Martin,

Thanks for calling this to our attention. Question: does this happen for any of the "B" oscillators or just one in particular? I will look into this right away. Any more details would be helpful.

thanks,
--mb

[MRBarton]

Martin,

Probably the best thing would be for you to make a preset demonstrating the problem and send it to me at:
[email protected]

thanks

[martin_l]

Hi Mark,

Thanks for coming back to me about that. I investigated it a bit more.It is only the 901ABB affected, the 901 single as well as the 921 series are ok.
Here is the weird thing: The left most (first) oscillator of the 901ABBB is fine. The problem only occurs for the second and third oscillators. For the thirs one it basically always crackles when going below a certain frequency, and for the second oscillator it happens sometimes (could be depending on the system load).

The patch to try is very simple: IU only used one 901ABBB and one standard Voltage Modular Oscillator. VM Oscillator goes directly to the output, and then I patch one of the B oscillator outs to the FM input of the VM oscillator.

I hope you can reproduce the problem. If not, let me know what else I can try to narrow it further down.

I also found a couple of other issues, which I will report in separate posts, to keep the discussion clean.

Cheers,
Martin

[MRBarton]

Hi Martin,

I'm still finding your description ambiguous. I tried a bunch of stuff with the module here and could find nothing wrong. You're going to have to send a preset for me to move any further on this.

--mb

[martin_l]

Hi Mark,

I will create a preset, when back to my music computer (I am in the office now). However, the preset literally has only the two described modules. The problem for me only occurs if I use small buffer sizes (64 samples). I will try whether I can make a screen recording.

Cheers,
Martin

[martin_l]

Hi Mark,

I managed to capture the problem in a video (attached). Unfortunately, the problem does not always occur. I have not yet found out when it does and when it does not. Also which of the B oscillators is affected seems to be a bit random. In the attached video it's all of them.

Please, also note the performance monitor, and how the CPU is going up from below 1% to something between 6% and 30% when the problems show up.

Hope that helps to see the problem. If you need any further information about my system, please let me know.

PS: attaching the video did not work, but I uploaded it (as unlisted) on YouTube:

https://youtu.be/R-sh4UJI0dU

Once you watched the video, I will delete it again.

Cheers,
Martin

[martin_l]

Hi!
Just wondering whether anybody managed to reproduce the problem?

Thanks,
Martin

[MRBarton]

This bug has been squashed and a new version will be published soon along with fixes and improvements to other modules. Our thanks to everyone who found and reported any anomalies. The VM community is the best and is another reason I only develop for this platform.

[Ian Craig]

This bug has been squashed and a new version will be published soon along with fixes and improvements to other modules. Our thanks to everyone who found and reported any anomalies. The VM community is the best and is another reason I only develop for this platform.

Yes and your work is much appreciated by many Mark. I just wish the modules/bundles were available for sale at locations other than the Cherry Audio store, as the Paypal option does not include the ability to use the Paypal credit I have to buy them. For those who do not understand, Paypal Credit has to be applied for from Paypal, it is not offered by the shops themselves, who receive full payment from Paypal, which is why I don't understand why the option does not come up in the Cherry Audio Store, as it comes up when using Plugin Boutique, who told me they didn't support it either, until I showed them that they in fact did (see screenshots). This why I have not been able to buy the the VM900. Anyway, just saying. Carry on the great work

2021-11-02 23_20_20-PayPal Checkout.jpg (122.6 KiB) Viewed 6489 times

2021-11-03 03_13_32-PayPal Checkout.jpg (152.15 KiB) Viewed 6489 times