need a very simple signal led circuit , not the Rane one

I searched here for a simple signal led circuit, one single led is enough.
I know the one on the Rane schematic, but simpler would be better.

Want to use it in the Gyraf guitar splitter thing

..take a look at the LA4 overload indicator - discussed before around here..

Jakob E.

thanks jakob, will look into it.

Here's a simple one, Andre:

http://www.thatcorp.com/datashts/dn113.pdf

excuse my ignorance, but what's the design (Gyraf guitar splitter thing) and where can we see it?

Cheers Dré

Try this one. I whipped it up this afternoon - simple one op amp, one supply, one LED peak meter. About as minimal as you can get.

http://mywebpages.comcast.net/tamron1958/Peak_LED_Meter.pdf

Suppa , flatpicker !!!

What type of opamp is it ?

See my edit above. I don't know - try what you have and see what works based on what I said.

1/2 LM358 or 1/4 of LM324 will swing nearly to ground and be entirely adequate otherwise.

Realize that you will get funny indications if your waveforms are highly asymmetrical---the Rane etc. circuits are somewhat more complex in order to avoid this.

This one is very close to 1/2 of the Rane version except that it rectifies positive instead of negative. Otherwise, the trick is to get the correct value of R1 for the reasons I put on the schematic. Probably could put a 1k trim-pot in series with a 100-200 ohm for R1 and adjust for the best performance/intensity. If it still acts a little flaky you may want to raise the 1uf to 2.2uf. Trade off is that it will respond a little slower.

Groner sent me a schematic to review which had a Rane circuit (he said, IIRC) that was full-wave---two diodes, one from each of the two balanced lines out of a preamp. I assumed that the one referred to was similar.

Yes, I believe we are talking about the same one, but for a guitar splitter, I assumed it would be unbalanced. Sorry, I should have mentioned that. Anyway, that was my reasoning for trying the 2.2uF in place of the 1uF - to compensate for the half-wave rectification.

Ok, I just put up the latest version (same link in thread above) which has the option for a balanced or single-ended input, along with notes for choosing op amp and LED current resistor. Thanks to Brad for helping me iron this out. :thumb: