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Ideas for converting a guitar signal to a trigger CV?

Started by jadesky, February 11, 2005, 02:52:53 AM

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jadesky

February 11, 2005, 02:52:53 AM
hi...i've browsed this place a lot, but this is my first time to post...

i was wondering if anyone knew of a circuit or existing device that can convert a guitar signal into a CV so it could be used to trigger an envelope of some kind...say, on a synth.  the only thing that's come to light so far is using a hex pickup of somesort, but i don't know if that's really the route i want to take...

thanks,
  ~ashley

puretube

#1
February 11, 2005, 03:13:57 AM
Hi jadesky, and welcome to the forum! ( 8) ).

Unfortunately, there`s no adhoc answer from me,
but some food for thought in the meantime, here:
http://diystompboxes.com/sboxforum/viewtopic.php?t=27022

http://diystompboxes.com/sboxforum/viewtopic.php?t=27346
http://diystompboxes.com/sboxforum/viewtopic.php?t=27431
http://diystompboxes.com/sboxforum/viewtopic.php?t=27252
http://diystompboxes.com/sboxforum/viewtopic.php?t=21783
http://diystompboxes.com/sboxforum/viewtopic.php?t=26027


[or try to find a Korg Traveler pedal... :wink:  :) ]
(sorry for this little joke  :oops: )

Maybe Stephen Giles, Mark Hammer, Vsat, stm, gez, or similar honourable gentlemen will chime in with more help...

(gotta find that crazy controlpedal I bought 18 years ago...)

jadesky

#2
February 11, 2005, 03:41:05 AM
thanks for the welcome and links, puretube. :)  a couple of those look particularly helpful.  i'll have to go through them more thoroughly when i'm a bit more awake...

as for the Korg traveler control pedal...i don't think i'll ever find that silly thing... <sigh>

gez

#4
February 11, 2005, 04:25:51 AM
One thing you might like to experiment with are simple digital filters made from re-triggerable monostables.  Driven from a comparator you can set up switching to be triggered when the guitar signal falls within a certain frequency band.  4098 chip, couple of resistors and a couple of caps, that's all you need (plus your switches).  You don't even need envelope control.  

If you read up on monostables (555 types) it should cover re-triggerable designs and you'll get the idea...
"They always say there's nothing new under the sun.  I think that that's a big copout..."  Wayne Shorter

Mark Hammer

#5
February 11, 2005, 12:29:22 PM
If you check the 1st issue of DEVICE that I have posted at my site (http://hammer.ampage.org, somewhere around page 9 or 10 of the site), you'll see a project for an input module for a guitar processing system that puts out gate, trigger, envelope, etc.  This unit will respond to notes or chords.  Elsewhere on the same site is a Penfold project for a mono interface for single notes that will put out trigger, gate and pitch-proportional CV.

There is a considerably simpler trigger/gate extractor that Craig Anderton published in Contemporary Keyboard magazine around 1981 (the issue with Paul Schaffer on the cover if you spot a pile of back issues in a music store).  I have the schematic but not with me at the moment.

PAiA's earliest envelope-follower/trigger-extractor module schematic is posted at Jack Orman's DMZ site: http://www.muzique.com/schem/2720-11.gif

puretube

#6
April 20, 2005, 12:52:05 PM

Dan N

#7
April 20, 2005, 02:12:08 PM
What a cool pedal! Is there an XR2206 in there?

puretube

#8
April 20, 2005, 02:46:57 PM
2x LM324; 1x TL071; 2 transistors...

maximee

#9
April 20, 2005, 03:04:37 PM
wow awesome pedal...


8)

Wild Zebra

#10
April 20, 2005, 03:13:46 PM
that pedal would be sweet with my X-911



"your stripes are killer bro"
"your stripes are killer bro"

DiyFreaque

#11
April 20, 2005, 05:07:28 PM
Funny this thread should come up - while waiting for parts for the next project, I figured I'd try something I've always wanted to try, and it involved Ray Wilson's Signal to Gate circuit on his Music From Outer Space site:

http://www.musicfromouterspace.com/analogsynth/signaltogate.html

Of course it puts out gate instead of triggers, but there are enough Schmit triggers left over to do a trigger out as well.

The idea I had was to record a track on my D8 using this circuit as a timing track.  I just ran a signal through a VCA and modulated the VCA with a square wave LFO at a high rate that I could divide down into different tempos.  Then, as I recorded other tracks, I would crank this track all the way to the left, run the signal out of the left output of the recorder through this circuit, then use that to sync a sequencer.  End result is that it turned my modular into a Casiotone rhythm machine  :D (well, I only had an eight step sequencer going).  This may be a cool technique for those of you with stompboxes that are triggered for one thing or another.  Everything would always be in sync as you recorded, without having to resort to MIDI....

The results can be found at the bottom of my Dual MS-20 Filter page (I used that filter in the tracks).  The third sample is my favorite.

http://mypeoplepc.com/members/scottnoanh/birthofasynth/id10.html

Cheers,
Scott

puretube

#12
April 20, 2005, 05:19:47 PM
err, this thread only popped up, coz I knew >jadesky< has been searching for a pedal like this for years (as has been known from the sig in the HC-FX-forum  :wink: ),
and I remembered having bought a similar pedal about 20 years ago in a sell-out,
and "just had to find it one day in the basement or the attic..." -
which I finally did, last weekend...

:D

maximee

#13
April 20, 2005, 06:09:10 PM
Hey Ton...
any more interesting finds we should know about?  :D

puretube

#14
April 20, 2005, 06:14:34 PM
sorry, no UA759 found yet...


[anybody seen >gez< lately?] (Imiss him...)

Dan N

#15
April 20, 2005, 06:18:55 PM
Actually, she is looking for a straight VC pedal that uses a DIN connector.

puretube

#16
April 20, 2005, 06:24:36 PM
so you think I`d better rip out the LFO and the tandem-pot,
and throw away the pots and switches?

(just joking - we`ve discussed the rest via PM... :wink: )

maximee

#17
April 21, 2005, 04:19:04 AM
Quotepuretube:   sorry, no UA759 found yet...

hehe, i didn't have that in mind when i asked but it's cool that you remember!    :wink:

puretube

#18
February 24, 2006, 01:49:29 PM
J. :  finally found the original bottom-plate  :icon_smile:

now we need a friend of yours/Zack, that can receive it from me @ the Frankfurt MusikMesse (~ apr. 1st), and bring it to you...

pinkjimiphoton

#19
November 12, 2011, 10:10:40 PM Last Edit: November 12, 2011, 10:14:43 PM by pinkjimiphoton
edit: oops...wrong thread, sorry!!
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