electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
Live streaming at radio.electro-music.com

  host / artist show at your time
<on air> EdisonRex Edison's Electronic Review
Please visit the chat
 Forum index » Clavia Nord Modular » G2 FAQ
Osc Phase Issue
Post new topic   Reply to topic Moderators: Nord Modular Editors
Page 1 of 1 [6 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
Chrono



Joined: May 18, 2008
Posts: 229
Location: NL
Audio files: 37
G2 patch files: 38

PostPosted: Thu Jul 26, 2012 2:27 pm    Post subject: Osc Phase Issue Reply with quote  Mark this post and the followings unread

Im stumbling on some problems when comparing the playability of the NMG2 and the Access Virus A.

so imagine 2 osc's connected to a Xfade. And in this case using 8 polyfonic Voices. OSC 2 is very slighlty detuned for the phase changes to become noticable.

NMG2: if u trigger a melody with just 1 key pressed at a time
the phase jumps around like changing its position everytime you press another or the same key.

Virus A: if u trigger a melody with just 1 key pressed at a time or repeat the same note. the phase moves without jumping to different positions.

-----------------------------------------------------------------------------
(for reference)
This problem won't happen in the NMG2 if voices are set to MONO.

When holding 1 key on the access virus and pressing a 2nd, then the phase changes its step. Noticable if you release the 2nd key again.
------------------------------------------------------------------------------

test patch is in the attachement
progress so far:
if the patch is reinitialized the technique works on 1 key
but after pressing more different notes the phase starts jumping to
different possitions again.

(solution should work with polyfonic setting)

I hope someone can help with this one!


NMG2 _ Access Virus A Phase.mp3
 Description:
Audio Reference of the problem
1st: NMG2 ,2nd Virus A, 3th NMG2 detuned, 4th Virus A detuned.

Download
 Filename:  NMG2 _ Access Virus A Phase.mp3
 Filesize:  572.97 KB
 Downloaded:  130 Time(s)


OSC Virus Phase-test01.pch2
 Description:
simple test structure

Download
 Filename:  OSC Virus Phase-test01.pch2
 Filesize:  1.46 KB
 Downloaded:  319 Time(s)

Back to top
View user's profile Send private message
ian-s



Joined: Apr 01, 2004
Posts: 2585
Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 612

PostPosted: Thu Jul 26, 2012 4:25 pm    Post subject: Reply with quote  Mark this post and the followings unread

The G2 only has the one poly key assign mode, which will always trigger a new 'voice' every time a key is pressed. Sad
Most early voice allocation synthesizers offered a choice of 3 poly modes. The virus might to, or perhaps they just chose a different fixed mode.

You can cheat in a limited way by using a single OscShpB with the double saw mode and a saw lfo modulating the shape 100%. The lfo rate then becomes your detune amount and you can select the Mono mode on the lfo. This will force all voices to have the same phase offset while the phase is still free moving.
Only good for that two saw 50:50 sound though.
Back to top
View user's profile Send private message
Chrono



Joined: May 18, 2008
Posts: 229
Location: NL
Audio files: 37
G2 patch files: 38

PostPosted: Thu Jul 26, 2012 4:58 pm    Post subject: Reply with quote  Mark this post and the followings unread

i see! , but still its strange the Logic "NAND"GATE manges to do it the right way for a moment.
_____________________________________________________________
You can reset the emulation by selecting GATE and then PHASE again in the path FX section.
__________________

just after a couple notes the more jumping occurs. I think that has something to do with the amount of voices, so the phase does not know wich one to choose and just jumps around.

It also seems to jump around quicker if u press notes further away from eachother.

I just cant think of an obvious solution to make it fixed.

It might need some serious brainwork to find this solution. but im sure there should be one.

i do not doubt your knowledge, ill have a try with the Shape osc. But it's main purpose is to work on every osc with a sync input.
Back to top
View user's profile Send private message
Roland Kuit



Joined: Sep 29, 2003
Posts: 1091
Location: The Netherlands/Sweden
Audio files: 8
G2 patch files: 127

PostPosted: Fri Jul 27, 2012 3:25 am    Post subject: Reply with quote  Mark this post and the followings unread

And if you take an osc with a sync input. The keyboard module gate out to sync in osc.? Also LFOB module can by reset by the gate out of the KB module. So you can leave it on Poly On, when modulating the Shape osc.
_________________
Roland Kuit
----------------------------
composer|research|synthesis|sound design|lecturer
http://rolandkuit.com/
Back to top
View user's profile Send private message Send e-mail Visit poster's website
varice



Joined: Dec 29, 2004
Posts: 731
Location: Northeastern shore of Toledo Bend
Audio files: 22
G2 patch files: 49

PostPosted: Sun Jul 29, 2012 5:09 pm    Post subject: Reply with quote  Mark this post and the followings unread

The problem that you describe is caused by the polyphonic “rotate” voice allocation mode of the G2. As Ian pointed out above in his post, the G2 *always* assigns each new note event to another available poly voice. But, just like a real poly analog synth, the free running oscillators in each voice of the G2 are phase independent. So, for a voice allocation scheme that always selects another voice for each new note, it will force the revelation of the phase differences of the oscillators in each poly voice, which you (along with others, including myself) notice as a problem.

The solution would be for the G2 to have an option for a more natural poly voice allocation mode “repeat”, where repeated notes are assigned to the same poly voice. Apparently, the Virus synth sound that you posted is based on a “repeat” mode.

Many poly synths have an option to select between voice allocation modes. I sure wish that the G2 also had these options. The default G2 poly “rotate” voice allocation mode limitation was discussed long ago. The last post by Dave Peck in this linked topic describes *very well* why it is *not* desirable to be limited only to the “rotate” mode:

http://electro-music.com/forum/topic-15459.html

_________________
varice
Back to top
View user's profile Send private message
Chrono



Joined: May 18, 2008
Posts: 229
Location: NL
Audio files: 37
G2 patch files: 38

PostPosted: Wed Aug 01, 2012 6:29 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks for that!
makes it more clear to understand the voice allocations compared with eachother.

I will post my G2-> Virus A patch soon.
just need to reduce some Cycles/Memory to fit all functions.
i will put that in the Synth section.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: Nord Modular Editors
Page 1 of 1 [6 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » Clavia Nord Modular » G2 FAQ
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use