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Building a Ring Modulator

Yoa01

Jun 18, 2012
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Need help identifying this diode

Hey all,

So this is my first real post other then my "I'm new post." Fancy.

So my problem is I want to build a passive ring modulator, and I have diodes (need to find a couple audio transformers, though) but I have no idea how to identify them. I've Googled just about every search phrase I can think of, but to no avail. I'm sure what I have is fine for my application:

Picture0001.jpg

I just want to be sure.

Thanks in advance!
 

CocaCola

Apr 7, 2012
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To get the authentic and proper sound you need to get matched germanium diodes, generally new old stock or pulled from vintage equipment and matched... You can use modern day Schottky diodes diodes but most will agree they produce an inferior effect... Silicone diodes are your last choice, they 'might' work but the effect if they do work is completely removed from the original effect and far inferior...
 

Yoa01

Jun 18, 2012
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Hey all,

So want to build a simple passive ring modulator pedal. The bypass switching is easy enough, but I want to know if this simple design is useable:
simple_ring_mod_scem_pic.jpg
After that, I want to incorporate a pseudo 555 with some controls, like this design:
RingModulatorSchematic.png
Will this work out? Using my limited knowledge of 555's, it looks like it'll work, but you're the experts.

YIM,
Yoa
 

Yoa01

Jun 18, 2012
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Is there a way to tell what these diodes are? I've heard someone using Schottkys in a ringmod and, though it was strange, it did have an interesting tone. If inferiority wasn't an issue, could you use any type of diode?
 

CocaCola

Apr 7, 2012
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Can we keep it in one topic?

https://www.electronicspoint.com/need-help-identifying-diode-t250298.html

Yes, you can use a 555 with a ring modulator, and yes your circuit is the classic ring modulator simple in design... The problem using a variable 555 is repeatably, if you find a setting you like repeating that value on the 555 is hard if not impossible without taking measurements and logging... Most people will design the 555 with a bank of fixed values that are selectable with dip switches, one selection can use pots so you don't lose the free form option...
 

Yoa01

Jun 18, 2012
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Terribly sorry, it seemed like a different kind of deal. I'll remember that.

I'm used to standard analogue stuff that has nearly no repeatability. That's not much of a problem. How would you incorporate those switches, just as another feature of the interface or would it need to be enclosed as to not change any of the switches? Or would it matter?
 

CocaCola

Apr 7, 2012
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You can use just about any diode, silicone being the worst while some silicones may not work...

The ones you have pictured/circled are generic small signal silicone diodes, probably your worst choice... Just get some germanium diodes and do it right, they are not hard to find new or new old stock...
 

CocaCola

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The switches would be part of the interface... You would use resistor values that produced the sounds you liked, but you would also have the ability to flip two switches on the dip switch putting two (or more) of your chosen resistors in parallel and thus creating a new sound...
 

Yoa01

Jun 18, 2012
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That is a really awesome idea! Only problem is... I'm going to show how much of a noob I am here... how do you connect the DIP/resistor assembly to the 555? And, just so I'm sure what you are talking about, you do mean having different resistor types on each switch, right?
 

CocaCola

Apr 7, 2012
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Using your example schematic you would simply replace the pots with the resistor bank like this...
 

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Yoa01

Jun 18, 2012
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You are quite possibly the most helpful person I've met on a forum... And, for extra fun, I could incorporate a switch to switch between pots and switch banks. Dude, major kudos to you, thank you!!
 

CocaCola

Apr 7, 2012
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Just replace one of the resistors with a pot in the modified design, and you have it all...

As I said when you flip one or more of the dip switches you are putting two or more resistors in parallel so you get more then just the simple 6 settings in that example... Replace one of the resistors with a pot and you have the full range again...
 

Yoa01

Jun 18, 2012
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RingModulatorSchematicDIP.jpg

So, I messed with the original a bit and added that and a few other ideas. This should work, right? Other than the messed up bypass switch, I mean. I just thought that that switch would only introduce the original signal to the output mix. Still a neat feature, I guess. I need a switch before the transformer, then I think I will be set.
 
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CocaCola

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That appears right but don't quote me on that, I didn't actually confirm the entire circuit, just gave it an overall proof of concept glance... Bread board it now and see how it works... And one of these days I will actually build one of these things, I picked up the vintage matched diodes and transformers about 10 years ago (damn time flies) maybe I will dig those parts out and actually do something with them soon...
 
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Yoa01

Jun 18, 2012
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I need to head over to Radioshack to grab some more parts, if they have them in stock. I should only need a 555 and the transformers, I have everything else. Thanks again for all your help and ideas!
 

CocaCola

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Rat Shack should have both of them in stock, ironically surprising as they never have anything I need... They have carried the transformers for years for interfacing to telephone equipment, I remember using them as a kid to make phone recording devices :) so I could pretend to be a spy...
 

Yoa01

Jun 18, 2012
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LOL that's pretty funny. I was surprised the other day when they didn't have MIDI connectors. They had every other jack, but not that.
 

Yoa01

Jun 18, 2012
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Update:

So I built the ring modulator (not the 555 part yet), and at first it didn't work. Then, I used this setup and it worked!
IMAG0014.jpg

Turns out, I used high-power diodes. I had to use this high-output distortion pedal with two outputs to get any signal to pass, but it does work! It just, well... note to self: don't ringmod two distorted signals together. Ever. It's literally just crackling with some semblance of pitch when you play a guitar through it.

Now, I just need to put together the 555 part! But, I have a slightly more fun idea that may incorporate this basic ringmod and the 555 as an oscillator: https://www.electronicspoint.com/simple-555-synth-idea-t252786.html

YIM,
Yoa

PS sorry for the yellow pic. My camera doesn't like the floodlights in my studio.
 

davenn

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Sep 5, 2009
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PS sorry for the yellow pic. My camera doesn't like the floodlights in my studio.

dunno if it was a phone camera or a proper digital camera

most proper ( read decent) digital cameras have a white balance setting/adjustment

with that you can set the white balnce for different types of lighting
eg ... sun, cloudy, .... for indoor .. tungsten, fluroescents etc

Dave
 
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