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 
 Forum index » Clavia Nord Modular » G2 Patches - Experimental
Oberheim DX Drum machine
Post new topic   Reply to topic Moderators: Nord Modular Editors
Page 1 of 1 [9 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
ian-s



Joined: Apr 01, 2004
Posts: 2575
Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 608

PostPosted: Wed Feb 12, 2014 12:41 am    Post subject: Oberheim DX Drum machine
Subject description: Some lo-fi 80's drum samples
Reply with quote  Mark this post and the followings unread

Here is another premature output from the web based tool I'm working on.

As a side track to the midi-pch2 converter, I thought I would dredge up an old idea. The unpublished app allows you to load ROM images from old drum machines like the DX and DMX, resample by 1:2 or 1:4 and save them in a patch file.
The Oberheim used a companded 8 bit data format (a-law) which was supposed to give a 12 bit dynamic range.
Rather than converting to linear 8 bit, I kept the same format and replicated the companding DAC in the patch.

There aren't that many of these type of drum rom images out there so now i'm working on a wav > pch2 (using the same companding).

The patch has 8 samples, 1 per variation.


OBDX.pch2
 Description:
80's drum roms

Download
 Filename:  OBDX.pch2
 Filesize:  12.53 KB
 Downloaded:  188 Time(s)


Last edited by ian-s on Fri Feb 14, 2014 11:38 am; edited 3 times in total
Back to top
View user's profile Send private message
Electromagnetic Wave



Joined: Apr 28, 2013
Posts: 81
Location: Kebek
G2 patch files: 12

PostPosted: Wed Feb 12, 2014 11:36 am    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
i'm working on a wav > pch2 (using the same companding).


Your projects are very interesting. Very helpful. I'm keeping an eye on it!

It's fun to change the tones manually with a patch like this! Again the "patch mutator" work well on this type of patch!
Back to top
View user's profile Send private message
ian-s



Joined: Apr 01, 2004
Posts: 2575
Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 608

PostPosted: Fri Feb 14, 2014 5:22 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks

I have updated the patch attached in the op. I was thinking of getting better timing resolution by running 2 parallel chains and multiplexing the outputs. While experimenting I discovered that the sequencers could run at 12,000Hz if they are fed a signal from the clock divider in square mode.

The new version has the same samples but now they can go twice as high and you can play them from the keys.

Hope to get the wav file utility on line before the end of the weekend.

My plans were to chain the sequencers into the FX area, giving 1024 samples per variation but it seems Clavia has limited the number of consecutive seq modules to 36 :¬0

With a bit of automated variation changing it still could be quite useful.
Back to top
View user's profile Send private message
Tim Kleinert



Joined: Mar 12, 2004
Posts: 1027
Location: Zürich, Switzerland
Audio files: 6
G2 patch files: 212

PostPosted: Sat Feb 15, 2014 4:10 am    Post subject: Reply with quote  Mark this post and the followings unread

Sequencers as sample ROM -lovely idea! Smile

Instead of doing the sample pitching via changing the clock rate (which is jittered by the system frequency and thus creates artifacts), one could play back the sample at a fixed base rate into a delay line used as a keyboard-tracking resampler, which gives the benefit of sample interpolation, unlimited keyboard range and optional anti-aliasing.

I've just moved yesterday, and my whole life is packed up into 30 cardboard boxes and various hardcases Laughing, but I might try this out once.

EDIT: Addendum:
Quote:
My plans were to chain the sequencers into the FX area, giving 1024 samples per variation but it seems Clavia has limited the number of consecutive seq modules to 36 :¬0

Yes, but the G2 numerical resolution is 24 bit, so actually you could cram three 8 bit samples into one sequencer stage. Of course, the encoding app as well as the playback circuit would be more complicated, but it's not impossible and would triple the sample time. 3*16*36=1728 samples.

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



Joined: Apr 01, 2004
Posts: 2575
Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 608

PostPosted: Sat Feb 15, 2014 12:58 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hi Tim, I was hoping you would see this. There is plenty of room for improvement in the playback patch and I am sure you can come up with something amazing.

I have started a thread on the conversion processor here.
Back to top
View user's profile Send private message
Tim Kleinert



Joined: Mar 12, 2004
Posts: 1027
Location: Zürich, Switzerland
Audio files: 6
G2 patch files: 212

PostPosted: Sun Feb 16, 2014 3:19 am    Post subject: Reply with quote  Mark this post and the followings unread

The 'sample playback via delay line re-sampler'-shtick is straightforward, I've used this technique many times for many purposes. It also has the benefit that the huge bulk of sequencers can move into the FX area, where 'stuff' is piped back to the voice area which only does the resampling -making polyphonic application a lot more feasible.

As mentioned, I've just moved and right now I don't even know where my G2Xs are Laughing, but I'll try to eventually get to it.

The other issue is causing more trouble: I've been trying to encode three bytes (8 bit) into a 24 bit word as used by the G2, in order to triple the available sample memory -and it doesn't want to work right now. Well, the encoding does work, but the decoding -getting the three bytes back 'out of there'- doen't work as intended, as I probably have false assumptions about the 24 bit fixed point numerical system of the G2 Sad We'll see...

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



Joined: Apr 01, 2004
Posts: 2575
Location: Auckland, New Zealand
Audio files: 42
G2 patch files: 608

PostPosted: Mon Feb 17, 2014 11:41 pm    Post subject: Reply with quote  Mark this post and the followings unread

Here is a simple de-multiplexer patch that clocks two rows of sequencers at Max frequency to effectively double the sample resolution.

You can see how much smoother the de-multiplexed output is in the screen shot.

Posted Image, might have been reduced in size. Click Image to view fullscreen.

And good news everyone, my original idea of having two banks, one each in the voice and fx area is still a go. More careful testing revealed that despite the LED's not woking, the extra sequencers continue to function so the limitation must simply be the editor LED protocol or something. AT audio rates, the LED is useless anyway.

Will hopefully get some more time to work on this soon.


multiplexsine.pch2
 Description:
test patch for high(er) resolution rom playback project.

Download
 Filename:  multiplexsine.pch2
 Filesize:  3.93 KB
 Downloaded:  134 Time(s)

Back to top
View user's profile Send private message
Electromagnetic Wave



Joined: Apr 28, 2013
Posts: 81
Location: Kebek
G2 patch files: 12

PostPosted: Tue Feb 18, 2014 3:22 pm    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
More careful testing revealed that despite the LED's not woking, the extra sequencers continue to function so the limitation must simply be the editor LED protocol or something.


Yes ! I was going to tell you about this. I had this problem in the past and it is documented on the forum.
http://electro-music.com/forum/topic-39858.html

Quote:
You can see how much smoother the de-multiplexed output is in the screen shot.


Very Happy Wow!!!
Back to top
View user's profile Send private message
dorremifasol



Joined: Sep 28, 2006
Posts: 775
Location: Barcelona, Spain
Audio files: 7
G2 patch files: 47

PostPosted: Wed Mar 05, 2014 7:00 am    Post subject: Reply with quote  Mark this post and the followings unread

Ian, this is amaaaaaaaazing!!
_________________
Cheers,
Albert
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic Moderators: Nord Modular Editors
Page 1 of 1 [9 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 Patches - Experimental
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