Tremolo schematic

[Bellyheart]

I know mostly where to look, but I wasn't having too much luck. I think it's too specific.. I'd like to make a tremolo that has selectable waveform and an expression pedal to control the speed. I think the expression part might be a little specific. Perhaps if someone can point me in the direction of the tremolo and someone to a how-to-guide of adding and expression in.

[aen]

I was considering this as well, but then I just went for the Small Bear kit. $45 for almost all the parts (no knobs) and instructions, and no prototyping or interweb hunting required.

[Bellyheart]

Yeah, I just saw that one. It's got a lot going on and is pretty cheap. I wonder if I can fit a CV in there.

[aen]

Deoends on how hte oscillator is controlled, but Im sure there is a way to do it, however complicated...

[elbandito]

I'd like to make a tremolo that has selectable waveform and an expression pedal to control the speed. I think the expression part might be a little specific.

Couldn't you just hook the 'rate' knob up to an expression pedal fairly simply? I haven't tried to make an expression pedal yet, so I'm not entirely sure.
Also JahSoul, I sent you a pm in which I offered to send you gut shots of the TVP1 but you never replied. Do you want them?

[Bellyheart]

Haha, I was stoned when I read that and guess I forgot to reply. Please do, please please do!

[aen]

I'd like to make a tremolo that has selectable waveform and an expression pedal to control the speed. I think the expression part might be a little specific.

Couldn't you just hook the 'rate' knob up to an expression pedal fairly simply?

Of course, this is exactly what Im goign to do, but an expression pedal is different than CV.

[Bellyheart]

Oh...see, this is my ignorance. I thought they were the same concept. No?

[aen]

Well, the same effect some times, but different methods. CV inputs accept actual electricity, and that electricity effects the unit. Expression input is just resistance (slowwing the electricity down, kind of) Moog pedals have both functions in the same hole, but i dont think that's standard. I could be wrong though.

[de.engineered]

Seems a few people replied while I was writings this and I changed a thing here and there to adjust accordingly, but this is ok enough as is...

Check this out:

http://www.geofex.com/Article_Folders/V ... ations.pdf

Geofex on a whole is a great resource. That link is more a cookbook (though not without schematics), but it teaches some basics very well, all the better for understanding and building stuff easier.

As for some LFO action, take a gander here:

http://musicfromouterspace.com/analogsy ... mpLFO.html

Or for some more waves action:

http://musicfromouterspace.com/analogsy ... ewlfo.html

Both circuits will work fine if you 'shift' power from -12V/0V Ground/+12V - to - 0V Ground/+4.5V/+9V. You can do that with a divider network, or get bipolar 9V from a circuit like this:

http://gaussmarkov.net/wordpress/circui ... er-supply/

(check the links on the right side of the page)


You can get *really* fancy with something like this, though it may be more than you need (or have to work with - a PIC programmer namely):

http://www.electricdruid.net/index.php? ... jects.lfo9


For footpedal control, you can use a switching jack to override the onboard pot, or use a pedal with a 250K pot (or a 200K if you can find one) in parallel with one in the circuit (normally a 100K), and control things an external expression pedal (volume pedal in this case), while the on-board pot proves some range control.


If any of that was too much/too brief, feel free to ask away :3

CV inputs accept actual electricity, and that electricity effects the unit.

Control voltage is a useful currency when it comes to having separate devices interact with each other. There are more in depth explanations (I can elaborate if you like), but on a whole it's something best left to synthesizers... it's a wonderful can of worms once you start noodling with that, but a can of worms nonetheless.

What jahsoul is looking to do is control a single variable, the LFO frequency, and one can do that by as said swapping the pot in the schematic (that would ordinarily be mounted somewhere) with the one in a volume pedal - just run a cable between them, a stereo 1/4" would do. Using your foot instead of your hand, simple mechanical substitution, no need for extra circuitry to make it consummately voltage controlled.

Geofex, ever useful, has an article on the topic (it's basically as said moving the pot elsewhere, and in the case here is all the easier b/c everything's being built from scratch, no tight enclosures to navigate):

http://www.geofex.com/Article_Folders/xprnped.htm

HTH

[Bellyheart]

Thanks soo much!

[de.engineered]

Thanks soo much!

Welcome! Any questions, fire away. Happy building :3

[jblank]

have you checked out the 4ms Tremulus Lune?

[Bellyheart]

Yeah, kinda big price tag, although it's a very good candidate.

[aen]

I got my kit today.

Freaking pad-per hole board. Harrumph.