Very cool, very simple cv controller -lovetone light jack

[charbot]

This might be old news, but I just stumble upon this: Lovetone light jack cv controller]http://cgi.ebay.com/Lovetone-Light-Jack-CV-Controller-for-Lovetone-pedals_W0QQitemZ270509810089QQcmdZViewItemQQptZGuitar_Accessories?hash=item3efba421a9] Lovetone light jack cv controller


"They were made for the Ring Stinger and Question Mark Flanger. They also work with other pedals with CV (controlled voltage) inputs, results vary. In the Ring Stinger the Light Jack controls the pitch of the oscillator and the delay time of the Question Mark Flanger (pictured pedal not included). The brighter the light source on the Light Jack, the greater the range. Hand movements between the light and jack can create with a bit of practice, very theremin-like effects.
This Item is no longer available from Lovetone. These Lovetone Light Jacks were custom made for me by Dan Coggins, designer of all Lovetone pedals. I was going to sell them with other another Manufactures pedal. That deal never happened and now here's your opportunity to get one. The Lovetone Light Jack is a stereo jack wired to a photo sensitive sensor. Your Lovetone Light jack will come in a small plastic bag with and a Lovetone Post Card."

Seems like its just  a CDS photoresistor wired to a phonojack.

[charbot]

by adding a switching jack in series or parallel with a control pot, this photocell jack could be plugged in and control any knob on nearly any effect.  You would have to experiment with the reisistance values.  Im sure some applications are more practical than others, but this still seems like something woth  with playing around with.   
Yesteday I finally got around to adding the experession pedal jacks to a meatball clone that I built a few years back.  This is the perfect project/toy for me until my real expression pedal arrives.   

[sean k]

Yesterday I had a good look through the contest submission archives and there was a circuit by Nelson which was a panning device and by removing the caps it could pan btween CV's. Hmm!

[Rectangular]

I've built a ton of these, they're pretty useful and fun to play with.  its sad to see $1.50 in parts sell for 50 USD , but I guess that's what you get for not knowing how to solder...

[charbot]

well, you get a lovetone card too!

[charbot]

just made one... the sensor jack, not the card.
very cool... especially in pedal jack #2 (intensity) on the meatball.
I found cds with a dark resistance of about  100k  and light resistance as low as possible works the best.(at least for the meatball.) I was surprised to find it had a highly articulated range.  I get get about a 5-8''.  Less dark resistance might strech out the range a bit.  
I had it on the floor with a lamp nearby. I could totally trigger wha's by wiggling my toes.   Perfect for lazy bedroom jams...
... and cheapskates.  

[LaceSensor]

Sorry to grave dig. Does anyone have a schematic to build one of these? Is it something so simple as two legs of a photoresistor wired to the tip and ring of a stereo jack?

Thanks!

[Mark Hammer]

Yes, although obviously the resistance range of the photocell, and how much it varies in the sort of lighting conditions you use it in, mimic what a standard expression pedal would do.  Many expression-pedal jacks simply want a variable 10k or 50k resistance to ground to do what they do.

My Line 6 M5 has an expression pedal jack that expects a variable 10k resistance.  Once I learned this, and without being aware of this thread, I wired up a photocell and secured it to the top of my guitar with tape.

I haven't tried it with everything the pedal can do (it essentially duplicates the entire Modeller series + the Verbzilla), but it works VERY nicely with their Whammy pedal emulation.  A fun thing to be able to stick it near your volume control and "work the whammy" with your pinky and ring fingers, wiggling them over the LDR.  Manual control of an LDR produces a different feel than foot control of an expression pedal, simply because of the speed and precision you can achieve with your hand.

[LaceSensor]

Cool thanks for the confirmation Mark!

[Ben N]

That would be an amazing thing to build into a pickguard, wired to a stereo jack along with the guitar signal, to control a filter.

[Mark Hammer]

I'm not sure if it is optimal to "build it in", Ben, since there is no single optimal way to use it, or any singular set of lighting conditions.  It would be tantamount to having a pedalboard come with a built-in wah, fixed in one location on the board.  A "convenience" of a sort, I suppose, but not necessarily ideally-suited to everyone's needs.

Having said that, a moulded cable that branches off to a signal cable with a phone plug at each end, and a control cable with a nicely encased photocell of suitable resistance range and sensitivity at one end and phone plug at the other end to plug into expression-pedal jacks, would be a nice thing to be able to pop into the store and buy.  Put some velcro on the back of the photocell module, and a piece on the pickguard, and away you go.

One of the nice things about photocells on board is that they let you do something different with your foot if you want, as well as providing a different feel.

[petey twofinger]

i had a cds in the pickgaurd of my memphis LP copy in 82 . i used it to control a transistor oscillator , and then later the rate on a small clone .

its pretty fun .