Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
Posted: Sun Jul 05, 2009 6:35 am Post subject:
Vosim Processor Subject description: VOice SIMulation
Hi all
i started a page to document a build of this module
vosim
The article & schematic were in Electronotes #130 (pages 3-10).
I have never found any other info on this design so decided this thread and my page will have to do. There are various versions of it for the Nord and in software.
just etched the PCB so far, when/if it gets finished and works will get some 'scope shots and samples up.
kewl. i've had my eye on that project for a while, even scored a pair of AD533s (hellish expensive) for the purpose. what changes did you have to make to use the 633? (beyond the change from round to DIL footprint).
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
Posted: Mon Jul 06, 2009 7:16 am Post subject:
It is the 1st time I have used an AD633, so just read thru the datasheet and compared it to the AD533.
in the AD633 datasheet fig.4 Pg.4 shows how to connect it to act as a squarer/freq doubler with a positive output, which seems to be the purpose of the AD533 in the Vosim.
I am hoping this will work as is and the trimpots will not be required, nor will the output amplitude need to be adjusted (optimist ).
if the trimpots are needed they can be accessed with just some links and if the output is too low i have placed holes to put resistors as necessary that will increase the output. You can see examples of how this is done on fig.5 and fig.8 (with equations)
Of course a few track changes, nothing very difficult - 20 minutes in photoshop
Probably the PCB could be reduced to half its size using quad op-amp packages, but let's see what its like 1st.
Repeating enveloped sin^2 burst followed by silence where the length of the burst + length of silence is the period of the fundamental and the sin is period of the formant?
I was thinking that you could approximate PAF synthesis on a modular.
output
^
|
VCA c--- sin wave oscillator at Formant frequency
^
|
Lag generator with separate rise/fall controls (controls bandwidth and skirt)
^
|
offset by 5v
^
|
A pulse wave at the fundamental
Alternatively you could replace the pulse/offset/lag with a VCS envelope.
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
Posted: Sun Jul 12, 2009 7:55 pm Post subject:
yes Kaegi's
this cct could be hooked up with modules but I don't think it would be exactly the same as the E/N cct.
back in 07 I asked about the Vosim on the E-M Nord forum - here
some interesting replies and MP3s to check out
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
Posted: Wed Jul 22, 2009 2:15 am Post subject:
just an update.
PCB stuffed and partly wired up
started thinking about the sync out.
The Vosim processor needs to be able to switch the VCO off to create pauses.
This is done in a similar fashion to hard sync on many VCOs, the difference is a regular hard sync usually has a cap, say 100pF, on the input path, meaning the sync signal is just a pulse, just enough to briefly short the cap.
so although the Vosim label says 'sync out' it is not sync as we know it.
i had a look around and decided Thomas Henry's VCO 1 would be suitable, it has a good sine out, only needs a 3080 and a quad opamp (without the pulse out subcircuit) and some people have already tested placing a fet over the intergrator cap to sync it.
so gotta build a new VCO.
am considering building a standalone synth based on this cct. To operate, it also requires an EG or LFO. A couple of those, maybe a joystick or Serge touch responsive switch and it'll be singing Daisy Bell....no worries
These were made with Ian's Jerkster humping the leg off a Thomas Henry VCO, the VCO sine out is hardwired to the Vosim input and the Vosim sync out does its duty to the OTA in the VCO. Nothing else, I just tweaked the settings of the Vosim here'n'there
Joined: Dec 29, 2006 Posts: 1176 Location: australia
Audio files: 4
Posted: Mon Sep 27, 2010 3:48 am Post subject:
Just a footnote regarding this module. The original designer, Dev Gualtieri, sent me an nice email this morning with pix of his original VOSIM and some of his synths he built back in the seventies.
He okay'd me to post them -
http://www.sdiy.org/pinky/vosim/vosim.html
scroll down
Joined: Dec 26, 2006 Posts: 144 Location: United Kingdom
Posted: Wed Sep 29, 2010 7:02 pm Post subject:
For those who want to 'Try before building', there is a VOSIM generator in CSound.
Some later experimenters used other wave shapes, and kind of generalised VOSIM into a branch of granular synthesis.
There are a few references in Curtis Roads book "The Music Machine". All the original papers are either locked into the dreaded JSTOR, or the AES who want $20 for a download.
Stan Tempelaars book "Signal Processing, Speech and Music" has more details, though it's not a cheap book, unless you can find a bargain second hand copy.
I think you'd need bunch of MARF style envelope generators to control the thing properly. The samples sounded amazing, though.
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 index » DIY Hardware and Software
FAQ
Calendar
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
Chat Room
Thanks for documenting and sharing.
).
