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 » DIY Hardware and Software
Analog XOR
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 1 of 3 [66 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Goto page: 1, 2, 3 Next
Author Message
frijitz



Joined: May 04, 2007
Posts: 1709
Location: NM USA
Audio files: 54

PostPosted: Fri Nov 16, 2007 1:42 pm    Post subject: Analog XOR
Subject description: (Whatever that means)
Reply with quote  Mark this post and the followings unread

A while back I built an XOR circuit ("digital ring modulator") to use with my various pulse waveform generators and shapers. Rather than using a digital IC I used an opamp design that I found in an old EN App Note. It worked just fine.

But then I got curious about what would happen if I fed it continuous (non-pulse) waveforms. After some head-scratching and calculations I figured out that what the circuit does is to go high whenever the sum of the two inputs is between -5V and +5V. And it does indeed produce some interesting ring-modulator type sounds.

To increase the circuit's versatility, I put in a pot that allows the lower threshold to be varied from the negative supply up to the upper threshold. So the output goes high when the sum of the signals is between x and 5V, where x is between -12 and 5V. I've just started to play with this, but it seems pretty cool.

Here are the schematic and a very short mp3 clip. For the clip, two TRI waves were sent into the unit via VCAs. The VCAs were run by envelopes from the AD/AR I mentioned in another thread. One AD is delayed from the other, which is set for a monostable-driven AHD envelope.

Enjoy!

Very Happy

Ian

NB: Edited to add modulation to schematic.


xor1107b.gif
 Description:
 Filesize:  4.51 KB
 Viewed:  12817 Time(s)

xor1107b.gif



demo_a1.mp3
 Description:

Download
 Filename:  demo_a1.mp3
 Filesize:  130.33 KB
 Downloaded:  955 Time(s)


Last edited by frijitz on Sat Nov 17, 2007 9:23 am; edited 2 times in total
Back to top
View user's profile Send private message
Usine Karate



Joined: Jun 09, 2007
Posts: 64
Location: Hackney Wick

PostPosted: Fri Nov 16, 2007 3:29 pm    Post subject: Reply with quote  Mark this post and the followings unread

This looks very interesting Ian. I would like to try it out this weekend. Is there however a recommended op-amp that you would use? I have lots of old 741's I'd like to find a home for, would these be okay?

Would different op-amps lead to differing thresholds re. -5v to +5v?

thanks, usine.
Back to top
View user's profile Send private message
frijitz



Joined: May 04, 2007
Posts: 1709
Location: NM USA
Audio files: 54

PostPosted: Fri Nov 16, 2007 4:05 pm    Post subject: Reply with quote  Mark this post and the followings unread

Usine Karate wrote:
I would like to try it out this weekend. Is there however a recommended op-amp that you would use? I have lots of old 741's I'd like to find a home for, would these be okay?
Would different op-amps lead to differing thresholds re. -5v to +5v?

Hi Usine --

There's nothing at all critical about this circuit and anything you throw together should give interesting results.

I used a TL072 opamp. A 741 will show some slew-rate limiting (the pulse edges will be sloped) but I wouldn't worry about that unless you need very high frequencies or very clean pulses.

The threshold levels I stated are approximate and based on 12 V supplies. If you use 15 V supplies you might want to increase the 220k resistor to something 270k or 330k.

Thanks for your interest Exclamation Please let us all know how this works out for you.

Very Happy

Ian
Back to top
View user's profile Send private message
toppobrillo



Joined: Dec 10, 2005
Posts: 766
Location: oakland, ca
G2 patch files: 1

PostPosted: Fri Nov 16, 2007 4:14 pm    Post subject: Reply with quote  Mark this post and the followings unread

cool- sounds nifty!
Back to top
View user's profile Send private message Visit poster's website
mosc
Site Admin


Joined: Jan 31, 2003
Posts: 17550
Location: Allentown, PA
Audio files: 123
G2 patch files: 60

PostPosted: Fri Nov 16, 2007 7:56 pm    Post subject: Reply with quote  Mark this post and the followings unread

I love this circuit. Very Happy

Very creative. Splendid... too much coffee

_________________
--Howard
my music and other stuff
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address
frijitz



Joined: May 04, 2007
Posts: 1709
Location: NM USA
Audio files: 54

PostPosted: Fri Nov 16, 2007 8:18 pm    Post subject: Reply with quote  Mark this post and the followings unread

mosc wrote:
I love this circuit. Very Happy


Many thanks, Howard Exclamation

Ian
Back to top
View user's profile Send private message
Rykhaard



Joined: Sep 02, 2007
Posts: 1290
Location: Canada

PostPosted: Sat Nov 17, 2007 12:45 am    Post subject: Reply with quote  Mark this post and the followings unread

MANY thanks Ian!! I'm just working on a multiple circuit utility panel at the moment with some optional spare space! One of these (at LEAST how you've shown) is going in!! (Desire to VC it has struck, immediately. Wink lol )

Great sound! I can't wait to build and modulate it! Very Happy
Back to top
View user's profile Send private message Yahoo Messenger MSN Messenger
mono-poly



Joined: Jul 07, 2004
Posts: 933
Location: Rotterdam, Netherlands
Audio files: 2

PostPosted: Sat Nov 17, 2007 3:49 am    Post subject: Reply with quote  Mark this post and the followings unread

And another simple great sounding circuit bij Ian!
Back to top
View user's profile Send private message
StephenGiles



Joined: Apr 17, 2006
Posts: 481
Location: England

PostPosted: Sat Nov 17, 2007 6:24 am    Post subject: Reply with quote  Mark this post and the followings unread

Ian, if the shape control could be replaced by a vactrol arrangement providing a similar voltage range, (probably not easy!) which is driven by an envelope follower control voltage derived from a guitar connected to one input, and say the output from a PLL (4046 perhaps) connected to the other, also driven by the guitar, we might have some interesting results. What do you think - on my desk 9am Monday morning!! Wink
Back to top
View user's profile Send private message
Blue Hell
Site Admin


Joined: Apr 03, 2004
Posts: 20272
Location: The Netherlands, Enschede
Audio files: 143
G2 patch files: 318

PostPosted: Sat Nov 17, 2007 8:05 am    Post subject: Reply with quote  Mark this post and the followings unread

Toyed a bit with this idea on the Clavia G2, very nice!

It was nice to put a bit of portamento (like 20 .. 30 ms/oct) on one of the ingoing oscillators - which were tuned 7 semitones apart (and playing some tune together).

Dynamic shape control is very worthwhile as well Very Happy

_________________
Jan
Back to top
View user's profile Send private message Visit poster's website
frijitz



Joined: May 04, 2007
Posts: 1709
Location: NM USA
Audio files: 54

PostPosted: Sat Nov 17, 2007 9:30 am    Post subject: Reply with quote  Mark this post and the followings unread

Hey folks ---

Thanks for all the interest Exclamation

Per requests I added a modulation section to the schematic. It's not obvious what the best way to do this is, but the one drawn works pretty well. I used a "switch hitter" so the sign of the modulation can be changed (zero modulation when pot is centered). The schematic in the original post has been updated.

Steven -- do I get a bonus, boss? Wink

Blue -- Thanks for doing the simulation. How involved was it to get the function put in?

Very Happy

Ian
Back to top
View user's profile Send private message
v-un-v
Janitor
Janitor


Joined: May 16, 2005
Posts: 8930
Location: Birmingham, England, UK
Audio files: 11
G2 patch files: 1

PostPosted: Sat Nov 17, 2007 9:52 am    Post subject: Reply with quote  Mark this post and the followings unread

hey Ian! that's an interesting looking circuit Very Happy

Thanks for posting it!

_________________
ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!
DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.
ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.
Back to top
View user's profile Send private message Send e-mail
Blue Hell
Site Admin


Joined: Apr 03, 2004
Posts: 20272
Location: The Netherlands, Enschede
Audio files: 143
G2 patch files: 318

PostPosted: Sat Nov 17, 2007 10:30 am    Post subject: Reply with quote  Mark this post and the followings unread

frijitz wrote:
How involved was it to get the function put in?


Not very Very Happy

The blueish modules implement it with the modulation being done as well.

The rest of the circuit is part of the noodle I built around it. This one does not have the portamento mentioned.


frijitz_xor.jpg
 Description:
 Filesize:  226.98 KB
 Viewed:  12798 Time(s)

frijitz_xor.jpg



_________________
Jan
Back to top
View user's profile Send private message Visit poster's website
v-un-v
Janitor
Janitor


Joined: May 16, 2005
Posts: 8930
Location: Birmingham, England, UK
Audio files: 11
G2 patch files: 1

PostPosted: Sat Nov 17, 2007 10:42 am    Post subject: Reply with quote  Mark this post and the followings unread

Laughing

I think that was probably my first ever encounter I had with Jan all those years ago, on the NM@code404 list. And it was a 'digital' ring modulator patch for the Nord. Very similar stuff. very easy too Very Happy

_________________
ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!
DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.
ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.
Back to top
View user's profile Send private message Send e-mail
EdisonRex
Site Admin


Joined: Mar 07, 2007
Posts: 4500
Location: London, UK
Audio files: 169

PostPosted: Sat Nov 17, 2007 2:52 pm    Post subject: Reply with quote  Mark this post and the followings unread

Hmm. Decided to whip it up on a breadboard and try it out. Took about an hour to get it to work. Odd little thing. What's interesting is when you try input 1 and 2 in somewhat harmonically related relations. It's not really like a ring modulator.
_________________
Garret: It's so retro.
EGM: What does retro mean to you?
Parker: Like, old and outdated.


Home,My Studio,and another view
Back to top
View user's profile Send private message Visit poster's website
v-un-v
Janitor
Janitor


Joined: May 16, 2005
Posts: 8930
Location: Birmingham, England, UK
Audio files: 11
G2 patch files: 1

PostPosted: Sat Nov 17, 2007 3:05 pm    Post subject: Reply with quote  Mark this post and the followings unread

EdisonRex wrote:
What's interesting is when you try input 1 and 2 in somewhat harmonically related relations.


mp3's??

EdisonRex wrote:
It's not really like a ring modulator.


yeah!!

I wish this course I'm doing would just hurry up and evaporate away Twisted Evil There are so many more important things in life apart from writing reports on FMEA- like building this pseudo ring mod Exclamation

_________________
ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!
DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.
ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.
Back to top
View user's profile Send private message Send e-mail
EdisonRex
Site Admin


Joined: Mar 07, 2007
Posts: 4500
Location: London, UK
Audio files: 169

PostPosted: Sat Nov 17, 2007 3:13 pm    Post subject: Reply with quote  Mark this post and the followings unread

v-un-v wrote:
EdisonRex wrote:
What's interesting is when you try input 1 and 2 in somewhat harmonically related relations.


mp3's??

EdisonRex wrote:
It's not really like a ring modulator.


yeah!!

I wish this course I'm doing would just hurry up and evaporate away Twisted Evil There are so many more important things in life apart from writing reports on FMEA- like building this pseudo ring mod Exclamation


I'll post some in the UK morning, if someone else doesn't beat me to it in the US evening or AU morning. Where's Krunkus, anyway? How long does it take to get back online?

Gonna play a bit more and see if I can't something resembling music come out of it.

_________________
Garret: It's so retro.
EGM: What does retro mean to you?
Parker: Like, old and outdated.


Home,My Studio,and another view
Back to top
View user's profile Send private message Visit poster's website
Blue Hell
Site Admin


Joined: Apr 03, 2004
Posts: 20272
Location: The Netherlands, Enschede
Audio files: 143
G2 patch files: 318

PostPosted: Sat Nov 17, 2007 3:15 pm    Post subject: Reply with quote  Mark this post and the followings unread

EdisonRex wrote:
It's not really like a ring modulator.


Seemed a bit between PWM and RM to me, sound wise, but with a rough edge when the ingoing amplitudes get low (having envelopes before the circuit, as in example above).

_________________
Jan
Back to top
View user's profile Send private message Visit poster's website
EdisonRex
Site Admin


Joined: Mar 07, 2007
Posts: 4500
Location: London, UK
Audio files: 169

PostPosted: Sat Nov 17, 2007 3:24 pm    Post subject: Reply with quote  Mark this post and the followings unread

Blue Hell wrote:
EdisonRex wrote:
It's not really like a ring modulator.


Seemed a bit between PWM and RM to me, sound wise, but with a rough edge when the ingoing amplitudes get low (having envelopes before the circuit, as in example above).


yeah, it's a lot like other Ian Fritz circuits.

Harmonically rich, usually explains them in 2 words.

_________________
Garret: It's so retro.
EGM: What does retro mean to you?
Parker: Like, old and outdated.


Home,My Studio,and another view
Back to top
View user's profile Send private message Visit poster's website
EdisonRex
Site Admin


Joined: Mar 07, 2007
Posts: 4500
Location: London, UK
Audio files: 169

PostPosted: Sat Nov 17, 2007 4:30 pm    Post subject: Reply with quote  Mark this post and the followings unread

well, v-un-v reminded me I can whip off mp3s at will here, and as I did build the circuit, here's some sound. I used square waves, although you can use others, it still ends up somewhat pulsed sounding, being a comparitor-ish thing. I tried to play a bit with the waveshape thingy but mine isn't behaving I think. Anyway, like I said, it's not really a ring mod nor is it PWM, but it's certainly rich.


fritz_xor_example_edrex.mp3
 Description:

Download
 Filename:  fritz_xor_example_edrex.mp3
 Filesize:  2.72 MB
 Downloaded:  870 Time(s)


_________________
Garret: It's so retro.
EGM: What does retro mean to you?
Parker: Like, old and outdated.


Home,My Studio,and another view
Back to top
View user's profile Send private message Visit poster's website
v-un-v
Janitor
Janitor


Joined: May 16, 2005
Posts: 8930
Location: Birmingham, England, UK
Audio files: 11
G2 patch files: 1

PostPosted: Sat Nov 17, 2007 5:20 pm    Post subject: Reply with quote  Mark this post and the followings unread

Nice one Paul Smile

Very 'fat'

_________________
ACHTUNG!
ALLES TURISTEN UND NONTEKNISCHEN LOOKENPEEPERS!
DAS KOMPUTERMASCHINE IST NICHT FÜR DER GEFINGERPOKEN UND MITTENGRABEN! ODERWISE IST EASY TO SCHNAPPEN DER SPRINGENWERK, BLOWENFUSEN UND POPPENCORKEN MIT SPITZENSPARKSEN.
IST NICHT FÜR GEWERKEN BEI DUMMKOPFEN. DER RUBBERNECKEN SIGHTSEEREN KEEPEN DAS COTTONPICKEN HÄNDER IN DAS POCKETS MUSS.
ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.
Back to top
View user's profile Send private message Send e-mail
EdisonRex
Site Admin


Joined: Mar 07, 2007
Posts: 4500
Location: London, UK
Audio files: 169

PostPosted: Sat Nov 17, 2007 5:29 pm    Post subject: Reply with quote  Mark this post and the followings unread

v-un-v wrote:
Nice one Paul Smile

Very 'fat'


you're welcome. Wink It is rather fat, isn't it. I used a little filter but if you watch this shit on a scope you can see what it's doing. A typical cool Ian Fritz circuit. Smile

_________________
Garret: It's so retro.
EGM: What does retro mean to you?
Parker: Like, old and outdated.


Home,My Studio,and another view
Back to top
View user's profile Send private message Visit poster's website
frijitz



Joined: May 04, 2007
Posts: 1709
Location: NM USA
Audio files: 54

PostPosted: Sat Nov 17, 2007 6:12 pm    Post subject: Reply with quote  Mark this post and the followings unread

Blue Hell wrote:
...
The blueish modules implement it with the modulation being done as well.

The rest of the circuit is part of the noodle I built around it. This one does not have the portamento mentioned.


Thanks Jan!

I don't understand the G2 well enough to figure out what you have set up. I would have expected two comparators to pick out signals (In1+In2) above and below certain limits then an AND gate to ensure both conditions are met. What you have done is equivalent to this?

Very Happy

Ian
Back to top
View user's profile Send private message
frijitz



Joined: May 04, 2007
Posts: 1709
Location: NM USA
Audio files: 54

PostPosted: Sat Nov 17, 2007 6:33 pm    Post subject: Reply with quote  Mark this post and the followings unread

EdisonRex wrote:
...I used square waves, although you can use others, it still ends up somewhat pulsed sounding, being a comparitor-ish thing. I tried to play a bit with the waveshape thingy but mine isn't behaving I think. Anyway, like I said, it's not really a ring mod nor is it PWM, but it's certainly rich.

Rex --

Thanks for trying this out and for the comments. If you use square waves (or more generally, rectangular waves) then I think you are recreating what the original Korg circuit does.
http://www.analog-synth.de/synths/ringmod/digital_ringmodulator.htm

In this case the waveshape control shouldn't have any effect, because rectangular waves always satisfy the threshold conditions no matter where the pot is set. If you have a chance to try out saw waves then the control should change the sound quite a bit.

I agree it's not all that much like a ring modulator. (Never understood why Korg called it that.) For example, if you feed both inputs the same saw wave, then you get a single pulse, whereas a true multiplier would give you sawtooth-like wave with a parabolic rather than linear rise. scratch

I'd like to figure out how to get bell sounds with this. Any idea where to start?

Very Happy

Ian
Back to top
View user's profile Send private message
Blue Hell
Site Admin


Joined: Apr 03, 2004
Posts: 20272
Location: The Netherlands, Enschede
Audio files: 143
G2 patch files: 318

PostPosted: Sat Nov 17, 2007 7:18 pm    Post subject: Reply with quote  Mark this post and the followings unread

frijitz wrote:
I don't understand the G2 well enough to figure out what you have set up. I would have expected two comparators to pick out signals (In1+In2) above and below certain limits then an AND gate to ensure both conditions are met. What you have done is equivalent to this?


Your description was that the output should be one when the sum signal would be < 5V or > 5v and zero otherwise, and I tried to do just that.

I assumed 10 V would be the max signal level and mapped 10 V onto 64 "Clavia control units" (the max, well, the unit units count really, there is some headroom above that). And so I had to map 5 V to 32 units.

I have two >= comparators, one set to a fixed value of 32 and another that can be controlled by input units (voltage equivalent), modeling the modulation on the lower value (it can go too high here with improperly set control voltages/units).

The xor on the outputs of the comparators will give the windowing function like you described it ... I hope the following table will prove that Very Happy

Code:


  >= -32 (or variable) | >= 32 | xor
  ---------------------+-------+-----
          0            |   0   |  0
          0            |   1   |  can't occur
          1            |   0   |  1
          1            |   1   |  0
         

_________________
Jan
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 3 [66 Posts]
View unread posts
View new posts in the last week
Goto page: 1, 2, 3 Next
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
emSynth

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