electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links
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 
go to the radio page Live at electro-music.com radio 1 Please visit the chat
poster
 Forum index » DIY Hardware and Software » Musical Interfaces
More accurate ladder chains for keyboards
Post new topic   Reply to topic
Page 1 of 1 [1 Post]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
Ricko



Joined: Dec 25, 2007
Posts: 251
Location: Sydney, Australia
Audio files: 27

PostPosted: Sat Jul 11, 2009 3:55 am    Post subject: More accurate ladder chains for keyboards Reply with quote  Mark this post and the followings unread

I don't think I have seen this in discussions or schematics.

But I noticed when looking at my Roland SH-3A that they do something interesting with their resistor chain for the keyboard.

Apart from the normal resistor chain, they also have extra high value resistors in parallel, maybe spanning three or so resistors each. There are a couple of these per octave, at various intervals.

It seems that the idea is that even with matched resistors, there can be an accumulated error up and down the keyboard. It is just a permutation issue.

So I suppose they measure the values of series of resistors and add a high value resistor to compensate for accumulated errors (where the values are too high.) It looks like this is a build-time decision about which resistors to add for better calibration, not a design time: the PCB has more suitable holes.
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic
Page 1 of 1 [1 Post]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » Musical Interfaces
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


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