New modulator schem,PCB,overlay - the Modulatron

[brett]

Hi.
Based on a simple circuit I saw a while back, I've developed this modulator for guitar (the "Modulatron").  Like most modulators this circuit lets a bit of modulator signal bleed trough when you're not playing, but it's better than some other circuits I've tried.  Perhaps best of all, it's made from easy-to-find, cheap parts, and the circuit is easy to understand, so there's lots of scope for simple modifications.

The only 1 control - a 1M(B) "speed" or "rate" pot.

Here's the schematic;http://members.optusnet.com.au/~jethro.dog/mypic114.jpg
The PCB;http://members.optusnet.com.au/~jethro.dog/mypic115.jpg
The layout and parts;http://members.optusnet.com.au/~jethro.dog/mypic116.jpg

cheers

[Aharon]

Thanks for sharing Brett.
Aharon

[Marcos - Munky]

Thanks a lot, Brett.

[norbizzle2012]

the links arent working....i was thinking of building it

[CheesyMoo]

Sad day. Link does not work for me either. Must have missed the boat.

[Taylor]

Whenever links die on the internet, you should try copying the URL into archive.org. Sometimes you get lucky...

http://web.archive.org/web/20060319174134/http://members.optusnet.com.au/~jethro.dog/mypic114.jpg
http://web.archive.org/web/20050214024520/http://members.optusnet.com.au/~jethro.dog/mypic115.jpg

Unfortunately the last one with the layout does not seem to be working.

[Renegadrian]

http://web.archive.org/web/20050214035919/members.optusnet.com.au/~jethro.dog/mypic116.jpg

working link for the layout

[norbizzle2012]

Thanks so much i would have never figured that out

[earthtonesaudio]

That's pretty cool!  At first glance it looks like you're summing in-phase and out-of-phase signals with 555's signal, getting some sort of tremolo effect, is that right?  Or is there some phasey/chorusy type sound going on as well?

[gigimarga]

Any chance for a soundclip?

[Taylor]

The first post was from 5 years ago -  since the schem and layout had disappeared, I'm guessing we're not going to get soundclips until somebody builds it again.

[brett]

Hi
apologies for the old stuff getting cut when I switched ISP. 

Here's the schem from the gallery:
http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=17571&g2_serialNumber=2

and a PCB:

http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=17572&g2_serialNumber=1

and overlay

http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=17574&g2_serialNumber=1

The circcuit is for a balanced modulator.  It sounds a lot like a ring modulator.  But it doesn't have as many hassles.  No gating like passive RMs.  If adjusted carefully, you can get rid of much (but not all) of the oscillator bleedthrough.  Note that it's a simple, primitive circuit that someone could fix up.  I had fairly limited knowledge and skills when I conceived it.

cheers