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
  Rob Adventures in Sound
Please visit the chat
 Forum index » DIY Hardware and Software
SN76477's Little brother, the SN94281
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
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
State Machine
Janitor
Janitor


Joined: Apr 17, 2006
Posts: 2747
Location: New York
Audio files: 24

PostPosted: Tue Dec 12, 2006 6:57 pm    Post subject: SN76477's Little brother, the SN94281 Reply with quote  Mark this post and the followings unread

I was just taking a peek into my parts bin and I came across 3 of these SN94281 IC's. Cool It's basically a stripped down SN76477 but it got me wondering, can it's VCO be 1V/Octave controlled using the Thomas Henry SN Voice circuit exponential converter? It would seem to me that it could as I doubt that TI would have changed the basic design of the VCO from this chip to the 76477.

There is no Attack/Decay module, no envelope generator and no external noise clock or noise filter. and no envelope lock feature like the 76477. It's still a cool little chip!! Very Happy

I have to take a peek at the data sheet as I see an interesting pin "AUDIO IN" ... Hmmmm ....

Anyone else have these? What are your thoughts?

Bill


SN94281.JPG
 Description:
 Filesize:  22.6 KB
 Viewed:  5887 Time(s)

SN94281.JPG



94281_pinout.jpg
 Description:
 Filesize:  27.28 KB
 Viewed:  3451 Time(s)

94281_pinout.jpg


Back to top
View user's profile Send private message Send e-mail
sneakthief



Joined: Jul 24, 2006
Posts: 529
Location: Berlin

PostPosted: Tue Dec 12, 2006 9:57 pm    Post subject: Reply with quote  Mark this post and the followings unread

Check out this schematic and see how it compares to the original SN76477 project schematics:

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

_________________
Sneak-Thief - raw electrofunk
Back to top
View user's profile Send private message Visit poster's website
bugbrand



Joined: Nov 27, 2005
Posts: 842
Location: Bristol, UK
Audio files: 1
G2 patch files: 1

PostPosted: Wed Dec 13, 2006 3:12 am    Post subject: Reply with quote  Mark this post and the followings unread

I just got hold of 4 of these (real cheap - it was a buynow ebay for 2 of them but I got sent 4!)

I've just done a PCB for basic test of the BeepBox schem - MikeFord asked me for this and then I located chips so I could do it myself. I made the PCBs yesterday, today I'll build, test & report!

The AudioIn, though, is just to get an audio signal in to the internal amp - no processing (I'm pretty sure..)

_________________
http://www.bugbrand.co.uk
http://www.bugbrand.blogspot.com
Back to top
View user's profile Send private message Visit poster's website
shawn



Joined: Dec 13, 2005
Posts: 209
Location: savannah

PostPosted: Wed Dec 13, 2006 8:25 am    Post subject: Reply with quote  Mark this post and the followings unread

I have one of those chips as well. In fact I have ANOTHER SN chip that is neither the 76477 or the 94281. I'll check my 'special' chips bins and find out what it is. I've been pondering what I could do with these chips.
Back to top
View user's profile Send private message
State Machine
Janitor
Janitor


Joined: Apr 17, 2006
Posts: 2747
Location: New York
Audio files: 24

PostPosted: Wed Dec 13, 2006 10:01 am    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
Check out this schematic and see how it compares to the original SN76477 project schematics:


OK, yes, I remember this schematic. Now I realize it's the 94281 Very Happy

Thanks ....
Back to top
View user's profile Send private message Send e-mail
bugbrand



Joined: Nov 27, 2005
Posts: 842
Location: Bristol, UK
Audio files: 1
G2 patch files: 1

PostPosted: Wed Dec 13, 2006 4:26 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hmm, so I didn't really like the results too much of the straight-up BeepBox design --- but didn't have time to tweak and bend and go over the datasheet again......
_________________
http://www.bugbrand.co.uk
http://www.bugbrand.blogspot.com
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: jksuperstar, Scott Stites, Uncle Krunkus
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 » DIY Hardware and Software
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