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fluxmonkey
Joined: Jun 24, 2005 Posts: 708 Location: cleve
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Posted: Mon Feb 11, 2008 2:16 pm Post subject:
Ring Modulators Subject description: or x-quadrant multipliers |
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2 versions from the net:
The MS20 ringmodulator
ARP 2-quadrant multiplier
I've built one of 'em (forget which), and it sounds great...
bbob |
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18197 Location: Durham, NC
Audio files: 212
G2 patch files: 60
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Posted: Mon Feb 11, 2008 5:08 pm Post subject:
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Cool, you are getting into this. These circuits aren't comparable to a fancy analog circuit like the AD530 or whatever, but they are lots of fun and have a unique sound of there own. _________________ --Howard
my music and other stuff |
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18197 Location: Durham, NC
Audio files: 212
G2 patch files: 60
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Posted: Mon Feb 11, 2008 5:24 pm Post subject:
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The little passive ring modulatos made from a ring of 4 Ge diodes and a couple of little audio transformers work great too.
From http://kraus.co.nz
This little 4 gate circuit works great. Stan Lunetta used the term pseudo ring modulators for things like this. The use of the word pseudo is important, IMHO, because it shows we aren't striving for real ring modulators, but something different and something that is OK on it's own.
No need for resistors, transistors, diodes, or anything else. Just wire this little gem up direct to your front panel with banana jacks and you're in business.
A G2 patch that works with the free G2 demo give you an idea what to expect.
Description: |
4 gate pseudo ring modulator. Works great in any Lunetta |
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1.9 KB |
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50068 Time(s) |
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Description: |
4 gate pseudo ring modulator to demo a circuit one could use in a Lunetta. Good on it's own though. |
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4 gate ring mod.pch2 |
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945 Bytes |
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3342 Time(s) |
_________________ --Howard
my music and other stuff |
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bugbrand
Joined: Nov 27, 2005 Posts: 846 Location: Bristol, UK
Audio files: 1
G2 patch files: 1
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Posted: Tue Feb 12, 2008 2:31 am Post subject:
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I've used the 4077 XNOR (Exclusive Nor) for quasi-ringmod for a long time now - I wonder how it'd compare to the schems posted above?! The 4077 is a quad chip so you get four XNOR gates in one chip - four (quasi) ringmods!
(quite possibly one of the circuits above is the 'equivalent' circuit of an XNOR gate -- its been a few years since I learned some logic stuff at college) _________________ http://www.bugbrand.co.uk
http://www.bugbrand.blogspot.com |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Tue Feb 12, 2008 6:14 am Post subject:
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bugbrand wrote: |
(quite possibly one of the circuits above is the 'equivalent' circuit of an XNOR gate -- its been a few years since I learned some logic stuff at college) |
Quite possible .. just spell out the truth tables .. it's easy really. _________________ Jan
also .. could someone please turn down the thermostat a bit.
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slabman
Joined: Sep 01, 2005 Posts: 102 Location: UK
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Posted: Tue Feb 12, 2008 2:47 pm Post subject:
digital frequency shifter |
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Great forum!
Hmmm.... In the analogue world, you can build a frequency shifter with a quadrature oscillator and two 4-quadrant modulators. So - could this be done in digital with 90-degree out of phase square waves and x-OR gates? And, would there be any point - I mean would it sound good?
Also, somewhere in this forum, I must mention pseudo-random binary shift registers - used for white noise but also arcade style sounds - and Walsh functions that can generate any arbitrary waveform from a handful of CMS pulses |
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GlassX
Joined: Jan 27, 2008 Posts: 50 Location: Brazil
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Posted: Wed Feb 13, 2008 5:41 pm Post subject:
Re: digital frequency shifter |
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slabman wrote: | Hmmm.... In the analogue world, you can build a frequency shifter with a quadrature oscillator and two 4-quadrant modulators. So - could this be done in digital with 90-degree out of phase square waves and x-OR gates? And, would there be any point - I mean would it sound good? |
Here's a simple circuit idea for a quadrature squerewave oscillator made with an NE567
I'm anxious... I'll by some NE567s tomorrow!!!!! |
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jnuaury
Joined: Feb 28, 2008 Posts: 161 Location: chicago
Audio files: 9
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Posted: Thu Feb 28, 2008 8:41 pm Post subject:
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i just built the 4 gate psuedo ring mod...
and then after returning to the forum i actually worked out the truth tables and the circuit is logically equivalent to a single XOR gate or the inverse of mr bug's XNOR pseudo ringmods
and of course i would have discovered this by clicking the first link in this thread and scrolling down
i havent had enough time to thoroughly test it out yet
but for now lets assume that using 4 gates will sound 4 times as good |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Fri Feb 29, 2008 6:28 am Post subject:
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jnuaury
Filling out truth tables is always a good exercise _________________ Jan
also .. could someone please turn down the thermostat a bit.
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18197 Location: Durham, NC
Audio files: 212
G2 patch files: 60
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Posted: Fri Feb 29, 2008 11:38 am Post subject:
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It's nice to have several ways to do the same thing because you can use whatever you have in your parts cache. _________________ --Howard
my music and other stuff |
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Scott Stites
Janitor
Joined: Dec 23, 2005 Posts: 4127 Location: Mount Hope, KS USA
Audio files: 96
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Posted: Sat Mar 01, 2008 7:59 pm Post subject:
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Nice thing about the XOR devices is you get four of them in a package. Fits hand in hand with all the oscillators you can yank off of a CD40106 or whatever. Of course, a lot of electronic cymbals use this for "shimmer". You can get a pretty decent gong sound out of a setup like that, among other bizarro stuff..... _________________ My Site |
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rubendelacosta
Joined: Dec 25, 2005 Posts: 153 Location: lisbon
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Posted: Sat Mar 15, 2008 3:36 pm Post subject:
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Probably off topic...and probably a dumb question but...
Can any of this circuits be feeded with general audio in put?( i'm experimenting with some radios, so "X in" one radio and "Y in" another radio signal).
Thanks, ruben |
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jnuaury
Joined: Feb 28, 2008 Posts: 161 Location: chicago
Audio files: 9
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Posted: Sat Mar 15, 2008 3:54 pm Post subject:
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yes, you can out other signals through these chips
some quirky things can happen
you can always use a 4049 to "square up" your input signal too
this works great if you want to run an external source into a divider or use your source to modulate the lunetta style non-vco oscillators |
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rubendelacosta
Joined: Dec 25, 2005 Posts: 153 Location: lisbon
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Posted: Thu Mar 20, 2008 8:50 pm Post subject:
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well....that schematic takes 3 NAND and 1 AND gate...right?
sorry, i'm kind of new to cmos logic.
thanks,
ruben.
edit:( i'm talking about the schematic that mosc posted) |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Fri Mar 21, 2008 4:05 am Post subject:
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rubendelacosta wrote: | well....that schematic takes 3 NAND and 1 AND gate...right? |
That is how it's drawn indeed, and it makes an XNOR this way.
An XNOR is an XOR with inverted output, or it's output is 0 when exactly one input is 1.
When you build it using four NANDS you'll get an XOR which make it's output 1 only when exactly one input has a 1.
There is no sonic difference between the two. Have a look at the 4070 and 4077 chips as well
A simple way to figure out these circuits is using thruth tables, like :
Code: | Basic truth tables :
AND : OR: XOR:
A | B | out A | B | out A | B | out
--+---+---- --+---+---- --+---+----
0 | 0 | 0 0 | 0 | 0 0 | 0 | 0
0 | 1 | 0 0 | 1 | 1 0 | 1 | 1
1 | 0 | 0 1 | 0 | 1 1 | 0 | 1
1 | 1 | 1 1 | 1 | 1 1 | 1 | 0
and their inverse forms
NAND : NOR: XNOR:
A | B | out A | B | out A | B | out
--+---+---- --+---+---- --+---+----
0 | 0 | 1 0 | 0 | 1 0 | 0 | 1
0 | 1 | 1 0 | 1 | 0 0 | 1 | 0
1 | 0 | 1 1 | 0 | 0 1 | 0 | 0
1 | 1 | 0 1 | 1 | 0 1 | 1 | 1
Using these for the following circuit (using four NANDs):
+-----+
+--------------------| | Y
| | & +o----+
| +-----+ +-----| | | +-----+
A ---+---| | | +-----+ +----| |
| & +o---+ X | & |o---- Out
B ---+---| | | +-----+ +----| |
| +-----+ +-----| | | +-----+
| | & +o----+
+--------------------| | Z
+-----+
A | B | X | Y | Z | out
--+---+---+---+---+----
0 | 0 | 1 | 1 | 1 | 0
0 | 1 | 1 | 1 | 0 | 1
1 | 0 | 1 | 0 | 1 | 1
1 | 1 | 0 | 1 | 1 | 0
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_________________ Jan
also .. could someone please turn down the thermostat a bit.
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beavis
Joined: Aug 23, 2007 Posts: 14 Location: US
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Posted: Fri Mar 21, 2008 7:29 am Post subject:
Re: digital frequency shifter |
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GlassX wrote: | slabman wrote: | Hmmm.... In the analogue world, you can build a frequency shifter with a quadrature oscillator and two 4-quadrant modulators. So - could this be done in digital with 90-degree out of phase square waves and x-OR gates? And, would there be any point - I mean would it sound good? |
Here's a simple circuit idea for a quadrature squerewave oscillator made with an NE567
I'm anxious... I'll by some NE567s tomorrow!!!!! |
The 567 is a great little chip--so many bizarre things you can do with it.
This is my latest 567 based circuit:
If you want to dig in to some others....:
http://www.geocities.com/tpe123/folkurban/fuzz/thing.gif
http://personal.inet.fi/koti/holmberg/schem.html _________________ www.beavisaudio.com |
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stolenfat
Joined: Apr 17, 2008 Posts: 476 Location: Sunny Oakland California
Audio files: 1
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Posted: Sun Sep 14, 2008 7:14 pm Post subject:
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in that quick doodle of the ringmod with the transformers, what does the carrier signal do? Is it like a control voltage? |
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RF
Joined: Mar 23, 2007 Posts: 1502 Location: Northern Minnesota, USA
Audio files: 28
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Posted: Mon Sep 15, 2008 5:33 am Post subject:
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That would be the second input signal. |
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stolenfat
Joined: Apr 17, 2008 Posts: 476 Location: Sunny Oakland California
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Posted: Mon Sep 15, 2008 5:13 pm Post subject:
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ah, so it is true ring mod multiplication. i have read people say it works but is so so, any chance theres a sound sample out there? Im really considering using this passive ring mod application in my next big project. Mainly because it look like a space saver, despite the huge transformers.
Also, BEAVIS, im very intrigued by your 567 trem/ringmod circuit you posted here. What kind of voltage does it run off? Could the Vcc be just a control voltage input and it could run off of that? Like a powerful sine wave?
Also, sound samples?
I really want to include a ringmod circuit into my next project, but am very concerned about it being able to run on lower voltages or batteries. I have no idea how to work with power supplies yet. My next project i have for seen as running off of like 8 or 9 ninevolt batteries, one to each modular.
Better ideas? |
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18197 Location: Durham, NC
Audio files: 212
G2 patch files: 60
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Posted: Mon Sep 15, 2008 5:27 pm Post subject:
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stolenfat wrote: |
I really want to include a ringmod circuit into my next project, but am very concerned about it being able to run on lower voltages or batteries. |
Then the passive RM is the one to use - no power.
BTW, for most purposes, the passive RM will sound great. It is a great beginners project. The transformers don't have to be big either. _________________ --Howard
my music and other stuff |
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stolenfat
Joined: Apr 17, 2008 Posts: 476 Location: Sunny Oakland California
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Posted: Mon Sep 15, 2008 6:55 pm Post subject:
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is there any chance that a pot could be added to control the amount of fx? it seems to me that this is kinda all or nothing? could it be added the carrier signal to control the amount of multiplication? |
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mosc
Site Admin
Joined: Jan 31, 2003 Posts: 18197 Location: Durham, NC
Audio files: 212
G2 patch files: 60
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Posted: Mon Sep 15, 2008 8:16 pm Post subject:
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stolenfat wrote: | is there any chance that a pot could be added to control the amount of fx? it seems to me that this is kinda all or nothing? could it be added the carrier signal to control the amount of multiplication? |
Building one will be self-illuminating. But simply put, if there is nothing on one input there will be nothing on the output.
X * Y = Z _________________ --Howard
my music and other stuff |
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Mikmo
Joined: Dec 01, 2005 Posts: 150 Location: Copenhagen - Denmark
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Posted: Tue Sep 16, 2008 6:22 am Post subject:
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Just remember that you MUST use Germanium diodes. Silicon diodes will not work. _________________ Stay Cool
Mikael
http://www.mikmo.dk |
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-minus-
Joined: Oct 26, 2008 Posts: 787
Audio files: 13
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Posted: Mon Jul 05, 2010 11:53 am Post subject:
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Bit of an old thread, BUT....
I was wondering whether pull down resistors are needed on input A and B of the 4011 NAND ring modulator mosc posted further up this thread? If so, are these the only pull down resistors needed? Probably a really easy to answer question for you guys! ...I have tried this on breadboard and the pull down resistors on A and B seem to help when only one signal is plugged in... before the second signal is connected. I guess I've answered my own question in a way.
Thanks! |
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Top Top
Joined: Feb 02, 2010 Posts: 266 Location: California
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Posted: Tue Jul 06, 2010 1:34 am Post subject:
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With the 4011 pseudo ring modulator do you get frequency doubling if you put the same signal into both input gates, like on a normal ring modulator?
I used to have an arp odyssey which used something like this, but you couldn't patch the inputs (they were fixed to the squarewave on each osc).
Also, re: germanium diodes in the passive ring modulator - you can use silicon. I have one using silicon that works. I have been meaning to sub in some germanium, but I haven't yet, so I can't say the difference, but silicon definitely does work.
-minus- wrote: | Bit of an old thread, BUT....
I was wondering whether pull down resistors are needed on input A and B of the 4011 NAND ring modulator mosc posted further up this thread? If so, are these the only pull down resistors needed? Probably a really easy to answer question for you guys! ...I have tried this on breadboard and the pull down resistors on A and B seem to help when only one signal is plugged in... before the second signal is connected. I guess I've answered my own question in a way.
Thanks! |
I think you would only need them if you don't have something hardwired to it. It's been my experience that any input gate you will be leaving open should have pulldown resistors. |
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