Nasty artifacts ...in signal path

The Cherry Audio CA2600 is a powerful, self-contained duophonic synthesizer inspired by the groundbreaking ARP 2600 synthesizer.
gentleclockdivider
Posts: 46
Joined: Mon Nov 02, 2020 3:57 pm

Nasty artifacts ...in signal path

Post by gentleclockdivider »

There is still some strange stuff going (latest update installed , today 10th novembre )
Set filter to bandpass 4 pole , resonance to 90 % percent , cut off to 100 hz and slightly modulate by lfo , the higher the resoance the nastier the effect
Here's an audio
https://app.box.com/s/p9p6s9469d8wflk20u9vrisrcqndm6fx
Image
Image

Wooww , here the filter is totally bypassed , only a sine wave straight to the output
These artifacts appear when bypassing the filter and also when filtering a signal ( see first screenhots )
What's going on cherry , you shouldn't release stuff so fast :mrgreen:
Image
Last edited by gentleclockdivider on Wed Nov 11, 2020 9:36 pm, edited 1 time in total.
rod
Posts: 24
Joined: Tue Dec 18, 2018 5:43 pm
Location: Singapore

Re: Nasty artifacts ...oscillators

Post by rod »

Very interesting. CA claim the low price doesn't mean low quality. (It doesn't have to, I picked up bx_oberhausen for about $20). But they have outsourced quality assurance on this. They should reward you for doing their job for them. And I agree it is still easy to find nasty artifacts.
martb
Posts: 184
Joined: Thu Aug 30, 2018 11:46 am

Re: Nasty artifacts ...oscillators

Post by martb »

gentleclockdivider wrote: Tue Nov 10, 2020 1:50 am There is still some strange stuff going (latest update installed , today 10th novembre )
Set filter to bandpass 4 pole , resonance to 90 % percent , cut off to 100 hz and slightly modulate by lfo , the higher the resoance the nastier the effect
...
Wooww , here the filter is totally bypassed , only a sine wave straight to the output
These artifacts appear when bypassing the filter and also when filtering a signal ( see first screenhots )
What's going on cherry , you shouldn't release stuff so fast :mrgreen:
I don't know what's going on. I have it set up the same here, on Renoise, but I'm not seeing the artifacts.

Image
upload png
gentleclockdivider
Posts: 46
Joined: Mon Nov 02, 2020 3:57 pm

Re: Nasty artifacts ...oscillators

Post by gentleclockdivider »

What's the slope factor in your spectrum analyser ( set ti to +4.8db) ,and what sample rate frequency in renoise ( I use 44Khz) ?
You can clearly hear it whn turning up the volume






Some further testing , a sine lfo of 3 hz ( Three Hertz ) routed directly to the output bypassing the filter , same artifacts at the same frequencies
These artifacts appear with audio and NON audio control signals
I have a suspicion this is the internal modulation rate of CA 2600 , I could be wrong because 3900Hz is incredibly low for an audio rate capable synth .
Image
Last edited by gentleclockdivider on Tue Nov 10, 2020 12:58 pm, edited 2 times in total.
martb
Posts: 184
Joined: Thu Aug 30, 2018 11:46 am

Re: Nasty artifacts ...oscillators

Post by martb »

gentleclockdivider wrote: Tue Nov 10, 2020 12:33 pm What's the slope factor in your spectrum analyser ( set ti to +4.8db) ,and what sample rate frequency in renoise ( I use 44Khz) ?
You can clearly hear it whn turning up the volume
Well, it was set at 'none', but I've now set it at 4.8db and the shape of the bump at 200hz now looks the same as in your images, but still no artifacts. However, switching from 48k to 44.1 the artifacts do appear.
gentleclockdivider
Posts: 46
Joined: Mon Nov 02, 2020 3:57 pm

Re: Nasty artifacts ...oscillators

Post by gentleclockdivider »

Cheers , so it's an internal sample rate problem
gentleclockdivider
Posts: 46
Joined: Mon Nov 02, 2020 3:57 pm

Re: Nasty artifacts ...oscillators

Post by gentleclockdivider »

C'mon cherry let's fix this
Miss Tinka
Posts: 14
Joined: Tue Oct 06, 2020 1:43 pm

Re: Nasty artifacts ...oscillators

Post by Miss Tinka »

Well; I tried the same settings in stand alone mode and heard nothing; even when I`m raising up the mixer`s audio to the maximum.

What could be seen; but not could be heard, makes no sense to me for an edit - if I am using this unit only to make music.
ColinP
Posts: 939
Joined: Mon Aug 03, 2020 7:46 pm

Re: Nasty artifacts ...oscillators

Post by ColinP »

I'm guessing that CA2600 uses the same native sample rate as Virtual Modular which is 48 kHz. So forcing it to convert to 44.1 kHz might be the cause of these artifacts. Although I am no expert in re-sampling.
gentleclockdivider
Posts: 46
Joined: Mon Nov 02, 2020 3:57 pm

Re: Nasty artifacts ...oscillators

Post by gentleclockdivider »

Sorry guys , but I am clearly hearing this ..it's a whinny high pitched sound
Route a sine lfo directly to vca output , disable reverb and crank up the output
Image
Sure it's not very loud , but loud enough to not unhear it
Even when I am just using low pass filtered bass lines , the sound becomess apparent
Here is a file , patch is shown in screenshot
https://app.box.com/s/s9ubkwgt394wzp5avw205ndaf0t711hg
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