Author Topic: Passive Ring Modulator  (Read 3226 times)

toneless

Passive Ring Modulator
« on: November 08, 2003, 06:12:53 PM »
Hi!

http://www.synthfool.com/ringmod.html
Has anyone build this effect?I've been trying the whole day to make
this fx work and i only get a lot of hiss noise and the signals
unmodulated.I used matched germanium diodes and two 10Kcenter tapped trans.Do i have to make something that the schematic doesn't have?Perhaps ground the jacks or something...?Has anyone tryed this fx with a guitar before?

Thanks
Nick Prionas

petemoore

Spicious
« Reply #1 on: November 08, 2003, 08:00:09 PM »
Doesn't look like you'd be getting enough voltage to meet Threshold or something yupp 'I think" [that's if those Ge's there are meant to clip in this ckt]...with a guitar pickup.
  Looks like maybe if you Drive it with something like a Booster [OA Fuzz/od?]...interesting looking schematic and all but not much supporting literature for a passive ckt like that.
  Not trying to waste your time till comeone who KNOWS of these things, I'm just itchin to post after being offline [puter kinda dies for a few days there].
  I Just finished boxxing a Simple Octave Up, which is quite nice, very low parts cnt., very nice searing 'upper area' octave with Fuzz,  with just a booster or plain guitar. It can also get Less of the full on octave like the FTM, and more of the 'ghostones' [I calls it] character like the TYCHO/Single Transformer'diodes type octaves.
Convention creates following, following creates convention.

R.G.

Passive Ring Modulator
« Reply #2 on: November 08, 2003, 08:55:10 PM »
The problem with all passive ring mods is that the signal you put through them has to be big enough to make the diode forward drops be neglible. You have to use bigger signals.  a few volts should do fine.
R.G.

Quick IQ Test: If anyone in a governmental position suspected that YOU had top-secret information on YOUR computer, how many minutes would you remain outside a jail cell?

petemoore

Next Question:
« Reply #3 on: November 08, 2003, 10:35:20 PM »
What ckt would drive a few volts?
Convention creates following, following creates convention.

drew

Passive Ring Modulator
« Reply #4 on: November 09, 2003, 01:37:44 AM »
You can easily do 10V peak-to-peak if you are using a bipolar supply (+9/-9v - just use two batteries, like some stompboxes) or if you're in modular synth land where all the modules are powered by +/-15V and typically send/receive 10v p-p signals.


drew
toothpastefordinner.com

brett

passive issues
« Reply #5 on: November 09, 2003, 02:58:45 AM »
Hi.  I use a passive modulator like this in my Dalekator pedal.  (It's at my website if you're interested).  

I used 8ohm:1kohm transformers (which give about 10 times voltage increase) to get over the diode problem.  I suspect that even 10V will be barely enough to avoid annoying gating effects.  With the transformers, my next problem was to drive the 8ohm inputs.  I used LM386s, which are very simple to set up and designed for just such a task.  In the end, I also upped the gain from the 386 and used a limiter (max 3V going in, about 30V at the diodes) to prevent excessive distortion on large signals.  It was fairly cool once finished, but there was lots of messing around to make it all work.  But have fun with it, there's some amazing sounds to come out of these things.
Brett Robinson
Let a hundred flowers bloom, let a hundred schools of thought contend. (Mao Zedong)

Marcos - Munky

Passive Ring Modulator
« Reply #6 on: November 10, 2003, 08:05:31 AM »
I have a question about this circuit. I'm building it, but in the schematic I see two input1, input2 and output connections. Wich one goes to what lug of the jacks?

toneless

Passive Ring Modulator
« Reply #7 on: November 10, 2003, 09:11:04 AM »
I think it doesn't matter...One connection to the "hot" the other to the "ground".I've been told that if everything is ok then you can use any jack as an input,carrier or output!
Please send a report if you manage to construct this.It is one of the
coolest effects out there...total sonic annihilation sounds :twisted:

Nick Prionas