A begginers doubt about LFO on Casio SK 1

[darwin1974]

Hi my friends.

I´m working on my SK 1. I am not very good with electronic but I think I.m doing a good mods.

My question:

I have done the 555 circuit to put an LFO on my SK 1 but.....is terrible, I don´t know where on the circuit table SK 1 I have to sold the different wires, I mean, Ground, power....sound from Sk 1 and the OUT.

I know, perhaps they are stupid questions but I don´t know who can help me but you.

Thank you so much!!!!!

DAVID.

[wax+wire]

What are you wanting the LFO to do? 

The Ground and 5V+ points i'd get by using my multimtere and finding which leg of one of the ICs has 5Vs going into it.
As far as the 'out', i've used an LFO for vibrato style pitch changing (though the SK1 has this built in).  What did you want to do?

[darwin1974]

Thnks wax+wire.

I wnt to put this circuit into my SK 1



I don´t know where i have to sold points A, B and C on the SK 1 keyboard.

What I want is to have a "vibrato" effect on the SK 1 sound and samples.

Thats all.

Thanks again my friend!!

[SynthularModulus]

Darwin, what wax+wire is asking is:

What are you trying to accomplish with the LFO? What aspect of the sound do you want to modulate with the LFO?

If you are just trying to get vibrato (there is an option for vibrato on the machine already--I guess you want to control the frequency of the vibrato with your circuit?) then just connect the ground of your LFO circuit to ground on the SK-1, and take the signal from your circuit and try connecting to one of the pins on the pitch trimmer. I'm not sure exactly which pin, just try pins on or near the trimmer until you hear it affect the pitch.

It should also be possible to get some sort of tremolo effect by connecting the signal from your LFO to the VCAs, but I am only guessing.

Other than that, there probably isn't much useful that an LFO will do for you on an SK-1. Your LFO is creating an analog signal, and the SK-1 is mostly a digital synth, save for the VCAs, so it won't "understand" an analog signal in the way you might hope. That said, you may be able to get some weird glitch effects by connecting your LFO to random bend points on the SK-1, but from what I have read from someone else who tried this, they weren't able to find much use for an LFO on the SK-1.

If vibrato is all you are trying to accomplish, why not (I hate to say it,) just add that effect using an external effects processor of some kind? Your time and money might be better spent by not pursuing an LFO modification, and instead focus on the dozens of mods that work and give great results on the SK-1. They have been discussed in detail on many threads on this forum and elsewhere on the internet.

That said, if you do pursue an LFO mod, I would be curious to know your results. Happy bending!