Build Your Own Clone Message Board

I took the LFO from the Runoff Groove Phozer and simplified it a bit. This is pretty useful for tremolo-type effects (I'll be posting a trem project soon), and I also plan to use it with a phaser I'm working on.

For trem-like behavior, the value for C2 is good at 10uf. For a slower sweep range that has a more rounded waveform, try a 22uf.


I'll post my own crappy vero layout later. I'm sure tonmann can do a better job.

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Function f(x)
TightCamera - Gear Reviews

That's a nice LFO topology you got there. I used similar in the Clarinot Cubed LFO mod:



I'm going to try this with the OTA phaser project too, minus the LED and plus a depth pot.........

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http://www.frequencycentral.co.uk/

Nice one, Rick. I think yours is simpler.


Cool. Can't wait to see what we come up with.

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Function f(x)
TightCamera - Gear Reviews

Do you have it on your breadboard? What if you replace the 2k pot with a 10k?

Now it's built on perf.

Earthtonesaudio looked at the schem weeks ago and also suggested a 10K trimmer. I'm sure it'll work, but maybe dialing in the right "intensity" would be harder? I don't know.

There is a lot that can be done to this LFO to make it more robust, feature-rich, etc. It's just a starting point.

I just happened to have a lot of 150K resistors laying around, but I don't see why they couldn't all be 100K instead.

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Function f(x)
TightCamera - Gear Reviews

And if anyone is wondering about the "phaser project" that Rick mentioned, here are the details:

http://circuitworkshop.com/forum/index.php?topic=174.0

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Function f(x)
TightCamera - Gear Reviews

150k is pretty standard. I have lots of 0.125W metal film that would work.

Remember not to place a bypass capacitor at pin 3 for this circuit. That would provide a low impedance path to 'ground' for the oscillator signal. This voltage divider needs to provide a sufficient AC load for the LFO signal. When you use 150k resistors, your load is half of that so you're in pretty good shape, 100k might be a little low, I'd think 470k would be better than 100k if you could take a little more noise.

Here's the layout:

For those of you who weren't privy to the gmail chat conversation that FF and I had earlier today ( ), the above layout is the LFO I posted here plus the audio path portion of FF's Eazius Tremor tremolo.



I think I'm also going to do another trem circuit with this LFO and the audio path from ROG's Improved EA Tremolo.

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TightCamera - Gear Reviews

IC1 is the light "transmitter," and IC2 is the "receiver".

I'm looking forward to this.. what kind of effect will this LFO have on the EA Tremolo circuit?

It's just replacing the "stock" LFO on the EA Tream. So it'll still be a tremolo, but with an optical LFO, which uses an LED to drive an LDR as a variable resistor, rather than the stock LFO that uses a JFET as a variable resistor.

Just a different way to chop the signal, that's all.

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Function f(x)
TightCamera - Gear Reviews

huh, neat. Still looking forward to it. I'm curious how the chops would compare to stock, and I suppose the next logical complication to this idea would be to have a switch toggle between the stock LFO and the optical one within the EA circuit. possible?

Definitely. The LFO itself is connected to the audio path by a single "wire", so you could swap them out with a SPDT switch. Easy-peasey.


Actually, you can tack this on to the end of just about any dirt box (or clean boost, preamp, etc) to get a sort of super-choppy trem effect. It sounds not very much like a typical trem. Very hard to describe. I guess the best way to describe it is sort of like a square-wave trem, so there is almost no rise and fall of volume; it's full on and then it's full off with not much in between. It sounds especially bizzarre at very slow speeds (1/2 second+ between waves).

You should try it just for fun. It's easy to have it on a switch to pull it completely out of the main circuit.

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Function f(x)
TightCamera - Gear Reviews