Sort Of Original Circuit

[variedsound]

Does anyone here know of a schematic for a circuit that wires LEDs to your pickups and the brightness of the LEDs vary directly with input of pitch coming into the pickup(For Example: Playing higher notes makes LEDs really bright and lower notes make them dull)? Has anyone ever done something like that?

I know it can be done, I just want to know if I need to draw my own schematic for it.

helphelp plx.

[lovekraft]

A standard frequency to voltage converter would do it - you could always use a generic analog tachometer circuit with the frequency response and output voltage scaled to whatever range you need for your application. But, yes, I'm afraid you'll have to "roll your own".

[gripper]

You can get just about what you want with a $15.00 "exploding Star" color organ kit that runs off a nine volt battery. I can't find the place that sells the good ones with the little circuit board but Electronics Goldmine has part number C6818 that you would have to cut the board down because it is fairly large. You do not have to tie into your pickups because it has it's own elecrolet mic. You get a crapload of leds with it too but the good kits I can't find are all red. Blue, yellow, white and red mixed makes it look better. You need to put little bleeder caps like in a tone control circuit on each output channel if you want the channels to follow frequency as well as volume. Mine has been running for two years on the same battery! I don't play that guitar much. LEDs rock!

[lovekraft]

All that color organ does is follow the signal amplitude - he's looking for a frequency follower.

[Paul Marossy]

A standard frequency to voltage converter would do it - you could always use a generic analog tachometer circuit with the frequency response and output voltage scaled to whatever range you need for your application.

Yeah, I guess that would probably track the guitar signal well enough in this case. In my experiments in designing a DIY guitar synth using that type of "tachometer chip", I found that it didn't track all the notes well. In fact, probably at least half of the possible notes on the neck it didn't recognize very well. Generally speaking, it didn't seem to respond very strongly to anything below the 12th fret, and then it would be real strong on anything above the 12th fret. IIRC, it likes the higher frequencies better. This is a different case than my application, though.

Let us know how it turns out if you whip up that circuit!

[ansil]

I sent a chap this type of circuit on this forum i think i posted it as well or he did one. a general circuit i foudn on the web.

[gripper]

Luvcraft, you are right, I guess. These little star-things are volume sensitive. I think it is the mic built in that makes the lower freq. show up more as loud, if that is very clear. The good ones come from CanKit P/N CK264 and THEY call them a VU meter. That means they are amplitude, not freq. My mistake . Not very good on electronics unless an automobile is involved.

[JoJo T. Magnifficent]

just a random stab in the dark (my digital electronics exam has been, so all info has been evacuated to make room for remaining exams) but woudlnt a stright capcitor to LED to GND work? low Freq notes would mean the Cap would have a much higher Impeadance in series so the LED wouldnt be as bright, and vice versa for High freqs. Youd probly want a current limiting resistor in there aswell.

Edit: Having had some time to think about it ( not that i did much thinking ), the diode may clip the signal if wired like that. but its worth lookin at, cause its a cheap and easy solution if it does work.

Edited November 13, 2005 by JoJo T. Magnifficent