LFO

[jossCardiff]

Just finished my first LFO thing, I think it's an LFO anyway.

http://allthebeesaredead.blogspot.com/2011/04/lfo-project.html

Also added a video of my last keyboard bent, the Bendinator 3. Now working on another one for a friend.

Took me ages to get this working, made some mistakes when tired, as soon as I looked at the circuit in the day I spotted my mistakes straight away. Suppose I shouldn't solder when tired really.

[Matt the Modulator]

yeah that's an LFO all-right great work and a nice idea using a led coupled to a LDR  you can get Vactrols which are basically led's coupled to LDRs but in a light tight package saves messing about making one (but not cheaper)

Anyway thanks I've been looking at a modulator for Buddha machine - ASMO has a schematic up but i made one and found it too temperamental but then i used slightly different parts i forgot about this method gunner get breadboarding

[jossCardiff]

Thanks.

I thought about buying a vactrol but they seemed a bit pricey on ebay, and I had the LED and LDR already so.

I used the simplest 555 flashing LED schematic i could find which was from The world's simplest 555 LED Fader

What's Buddha machine btw?

[Circuitbenders]

I'm a big fan of this circuit for LFO's



For a start the triangle waveform shape is continuously variable from ramp up, through triangle, to ramp down. The pulse output also varies between a pulse spike, through a square waveform and to an opposite pulse spike.

Its part of a bigger circuit that uses the other 2 opamps in the TL074,. You only really need to use oth sides of a TL072 or similar, rather than the TL074 on the diagram,

[jossCardiff]

That looks better but then more complicated too.

i've only being doing this a few months, that looks scary to me at first glance

[Circuitbenders]

With schematics that initially look a bit daunting, i find it pays to actually count the number of components involved.

On that you've got:

1 x dual op amp
2 x Diodes
1 x capacitor
8 x resistors
2 x potentiometers (plus another one if you want depth control)

and thats it. It looks a lot more complicated than it is.

Powering the circuit might prove a little more difficult but nothing that a little reading up on op-amps and PSU's wouldn't solve.

[jossCardiff]

I guess it's good to push my brain a bit anyway, might have a go at it. I've seen one on Youtube that had three pots, so that must have had depth control , and that was pretty cool.

[the_zombiest]

it was probably this one that you've seen on youtube: http://www.casperelectronics.com/images/finishedpieces/speak-n-spell/Speak-n-Xbending/LFO%20schematic2.jpg
It's a straightforward build and very effective on the majority of toys.
Good ol' Casper.
I like the look of yours too Paul.
I'd built one similar out of a TL062 but it was pretty temperamental...

[jossCardiff]

that looks cool, nice easy to follow drawing too

the one I saw was RC CIRCUIT BENT RETURN OF THE DROID LFO DRONE SYNTH

i'd love to get hold of a speak and spell or something similar