Defective multisample Saw (Kross 2 and maybe others)

Puukka · Post by **Puukka** » Fri Jun 01, 2018 3:10 pm

I´m currently studying the Kross 2 and I realized a strang behavior of the sample wave Saw.

1.) Take an InitProg patch,
2.) At the P-OSC page select Saw (311)
3.) Filter Cutoff Frequency to as example 50-60

You´ll realise a big sound difference when changing from D5 to D#5

A workaround would be to use Saw-MG3 (I guess MG means Moog. But what means 3, anyone having a clue?

Thanks and kind regards,
Herbert

OpAmp · Post by **OpAmp** » Fri Jun 01, 2018 7:42 pm

Hi,

I replicated the issue also on the Kross (1). The sample number is different (266) but, indeed there is a huge difference.
I looked at spectra of the D5 and D#5 notes and played around with the cut off frequency. There is indeed something wrong with the sample.

From D5#, it looks like
1. another sample is taken for which harmonics abonve +/- 10kHz are gone
2. the cut off frequency of the filter halves
Given that by default the filter is a 4 pole one, the shift of the cut off frequency substracts suddenly a lot more harmonics by going from D5 to D#5, resulting in a huge difference in sound (saw to sine like).

Looks like a bug in the sample and/or engine. Too bad...

Puukka · Post by **Puukka** » Sat Jun 02, 2018 6:35 am

Thanks for replicating and your accurate analysis.
Yes, as would react the filter as you stated.
But because it seems to get normal again at F#6, it seems to be the streched sample at that range.

I´ll be able to live with it using Saw MG3 instead but I´ll try to communicate it to Korg support, that they might correct it for the next workstation.
I also guess, that Krome and maybe Kronos are using the same sample.

Kind regards from Austria,
Herbert

Puukka · Post by **Puukka** » Tue Jul 10, 2018 9:01 am

Here´s an update.
German Korg support confirmed the issue and told me to report it.
By the way, Krome don´t have that issue even using the same sample "Saw".
So maybe it could be repaired by a firmware update?

Regards,
Herbert

OpAmp · Post by **OpAmp** » Tue Jul 10, 2018 8:38 pm

Hi,

That would be great!

But I doubt I will get an update for my Kross (1)...

Thanks for contacting Korg Support concerning the issue and reporting here back.

Bye