To my ear, it sounds more like it is mixing the signals, rather than multiplying them.. There is always a signal bleeding from both modulator and carrier inputs. My understanding of a ring modulator, is that both the carrier and modulator should remain silent until they are modulated by each other?
Also there's no calibration procedure in the docs, perhaps this is where I'm going wrong?
First I tried two square waves, and offset the modulator frequency. Secondly I used a drum machine for the carrier. It certainly modulates, but doesn't sound anything like a classic ring circuit. Maybe I'm doing something wrong here? I will do some more experimenting _________________
Joined: Mar 28, 2006 Posts: 1497 Location: Kansas City, Mo USA
Audio files: 45
Posted: Mon Nov 01, 2010 2:03 pm Post subject:
LektroiD wrote:
To my ear, it sounds more like it is mixing the signals, rather than multiplying them.. There is always a signal bleeding from both modulator and carrier inputs. My understanding of a ring modulator, is that both the carrier and modulator should remain silent until they are modulated by each other?
Also there's no calibration procedure in the docs, perhaps this is where I'm going wrong?
First I tried two square waves, and offset the modulator frequency. Secondly I used a drum machine for the carrier. It certainly modulates, but doesn't sound anything like a classic ring circuit. Maybe I'm doing something wrong here? I will do some more experimenting
If either of your signals has a DC offset, then you will get bleedthru.
You want to be sure that the CV input voltage is not causing a DC offset. Also, you want to be sure that your input signals have no DC offset.
A square wave that is 0v to 10v will have (in effect) a 5v DC offset. _________________ -- Kevin http://kevinkissinger.com
Also there's no calibration procedure in the docs, perhaps this is where I'm going wrong?
will follow.
for now:
if you don't have a scope - don't apply any signal to any input. turn all pots down. turn input 1 pot up (still no signal at the input!), use trimpot to get 0V at test point TP1. then same for 2nd input.
if you have a scope - apply a signal to channel 1, input pot all up. use trimpot to move signal centered around 0V. _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
Joined: Apr 19, 2010 Posts: 346 Location: San Francisco, CA
Audio files: 13
Posted: Fri Nov 12, 2010 1:00 pm Post subject:
LektroiD wrote:
I'm now wondering how to do a 5U for this, If I do standard MOTM 1U, I'll have nowhere to put the extra socket, and it seems a little wasteful to use a 2U panel just to accommodate 1 extra socket. I may have to use smaller rotary knobs and place the sockets next to each of those
Any other 5U guys out there building this?
I'm going to do a 2u and fill out the space with either one of Nicolas' simple VCOs or simple LFOs, as either would be useful on its own, as well as in conjunction with a VC Ring.
Joined: Mar 28, 2006 Posts: 1497 Location: Kansas City, Mo USA
Audio files: 45
Posted: Mon Nov 15, 2010 9:29 am Post subject:
Powered up the VC RingMod last night
Powered it up and got sound out of it! ** Hooray!! **
Both VCA's work ok. The Carrier signal is ok. The Modulator signal is clipped though ... so, I have some troubleshooting to do. I can already see that this will be a fine addition to my synthesizer.
I'll post a pic once it is finished -- as tempting as it is to post a pic, I wait until everything works to spec before I do the show 'n tell thing. _________________ -- Kevin http://kevinkissinger.com
Posted: Mon Nov 15, 2010 3:40 pm Post subject:
Re: Powered up the VC RingMod last night
kkissinger wrote:
Both VCA's work ok. The Carrier signal is ok. The Modulator signal is clipped though ... so, I have some troubleshooting to do.
does it clip at the testpiont TP2, or does it clip at the output? latter would be the feature, not a bug. _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
Joined: Mar 28, 2006 Posts: 1497 Location: Kansas City, Mo USA
Audio files: 45
Posted: Tue Nov 16, 2010 7:17 am Post subject:
Re: Powered up the VC RingMod last night
fonik wrote:
kkissinger wrote:
Both VCA's work ok. The Carrier signal is ok. The Modulator signal is clipped though ... so, I have some troubleshooting to do.
does it clip at the testpiont TP2, or does it clip at the output? latter would be the feature, not a bug.
Thank you for your comment. The waveform is not clipped at TP2 and TP1.
I checked and re-checked the polarity of the diodes and verified that the op amp is working correctly. Thank you for verifying that the module is working to spec.
I will get some sound examples up soon. Stay tuned... _________________ -- Kevin http://kevinkissinger.com
Joined: Mar 28, 2006 Posts: 1497 Location: Kansas City, Mo USA
Audio files: 45
Posted: Thu Nov 18, 2010 9:30 pm Post subject:
VC Ring Modulator MP3 Demo Track
I just recorded a demo and a short improv with this module.
One adjusts the signal levels (the carrier and modulator -- X and Y) to null out the primary input signals.
Since the Voltage control varies the X and Y levels, external voltage can control the nulling effect ("bleed through") and effect some amplitude modulation, too.
I labeled the inputs X and Y to match the Aries labeling (used for the Aries Balanced Modulator).
VC Ring Modulator Demo.mp3
Description:
Demonstration and short improv with the Fonitronics mh31 Voltage Controlled Ring Modulator
Filesize:
5.78 MB
Duration:
6:19
Viewed:
2864 Time(s)
PB170008a.JPG
Description:
The VC Ring Mod didn't utilize all of the Aries 9x3 panel, so I added a separate Gain/Bias function to the module.
Filesize:
1.29 MB
Viewed:
690 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.
PB170009a.JPG
Description:
This view shows the VC Ring Mod PCB
Filesize:
1.6 MB
Viewed:
677 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.
PB170011a.JPG
Description:
This view shows the Gain/Level Shifter PCB.
Filesize:
1.56 MB
Viewed:
657 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.
BTW did you try the VCmodulator for control voltages as well? _________________
cheers,
matthias
____________
Big Boss at fonitronik
Tech Buddy at Random*Source
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