Fun with LDRs (or Do You Want Another Knob for Your Tremulus Lune?)

[trjones1]

I breadboarded the DOD 280 optical compressor today, and while I didn't love the sound of it, it got me thinking of ways to use the variable resistance circuitry in other applications.  First I split the signal and sent one side to a Rat and the other to the 280, which I set up to just sense the level of the incoming signal.  I put the 280's LDR in parallel with the gain pot from a Rat and get a really terrible facsimile of tube sag.  The harder you play, the less gain there is coming from the Rat.  This might have been cool, but the LDR was so slow in reacting that it took too long to get a good bloom of gain on the notes. 

Next i hooked up the LDR in parallel with the speed pot of my Tremulus Lune.  Now this is cool.  The speed of the tremolo becomes dependent on how loud you play, so when you first hit a chord, the tremolo becomes fast and slows down as the notes fade.  You can set the speed knobs of the Tremulus as the baseline tremolo speed and the sensitivity knob of the 280 controls how much faster the tremolo can get when you start playing loud.  I found a 500K reverse audio pot to be best for sensitivity.  You could even use a switch which puts the LDR in parallel with either the fine pot or both speed and fine knobs together to make a sensitivity range control.  It's probably not the most useful sound in the world, but I like it. 

I think one problem with my setup right now is that there might be some tone suckage since you have to split the guitar input to go to both the tremulus and the 280 circuit in order for the 280 to detect the level of your playing.  I a/b'ed the tremulus circuit with both the 280 connected and disconnected and couldn't hear any big difference in tone, but you might want to buffer the input to the 280 circuit.  Any thoughts?

[petemoore]

  Yes !
  Very cool !
  Tremolo that super tremulates when you hit a note and slows down again after is a neat idea, and should make interesting 'statments'.

[rousejeremy]

This is a great idea. Has anyone spliced this into a Tremulus Lune?

[MmmPedals]

Thats what its all about. I would love to hear some clips.

[rousejeremy]

Maybe there's a way to separate the LDR portion of the Ross and splice it into the Tremulus Lune.

[salocin]

An envelope controlled tremolo. Have been playing with idea for a while. Still haven't managed to get it just the way I want it though.

[FunkyGibbon]

This would be an even more fantastic idea if you could also set the envelope to ramp up, i.e. make the Tremulus Lune speed up as the note decays. I have a Guitar Rig preset that I made which does this and I particulary like it for a clean (not very distorted) lead sound, with a Moog filter also envelope controlled. As yet I don't have the pedals to do it for real!

I based the idea on some sounds in Pivot's song 'Helps None But Hurts None', which is well worth the listen if you can find it. The guitarist used one of those silver Korg ToneWorks multieffects to get a similar sound on stage.

Anyway, ramp-up tremolo speed would be great!

Christopher

[FunkyGibbon]

...and well done for the lateral thinking!

[trjones1]

You could make it speed up by putting the LDR in series with the speed pot instead of parallel to it.  The problem you'd run into is finding an LDR that had the right range of resistance.  As it is now, running the LDR in parallel, it doesn't make too much difference if your LDR's dark resistance is 300k or 500k or 1M.  However, if you put that same LDR in series, you'd have your trem running way too slow when the LDR was dark.  You could mess around with the capacitor that goes from lug 1 of the speed pot to ground to try to deal with this problem, or just try to find an LDR with as low a dark resistance as possible.  I think I saw one at Furturlec that was 100k.