confusing at best The circuit was from what I can gather at this point from a Greek company and has morphed a little as it changes Countries. The 4.7uF was my typo, it is actually a 4.7nF My project only requires one channel so I take it any of the 3 sets of caps will do what I need. I sent an email to the USA distributor yesterday asking for more detail on the circuit and they sent me back the entire Kit's building instructions, including a parts list and schem All is needed now is to mod the circuit a bit to accept some 3500 mcd 2.0v 20ma LEDs. It looks to me to drop the Zener to 2.0 volts and possibly correct the ballast resistor(R17). Correct? Thanks for clarification on the caps. Aurbo
The zener D1 and its ballast resistor R2 set up a virtual earth at around half supply voltage on one op-amp input so the ingoing audio sine wave can swing either side of the new 'ground'. Leave that side alone or the filters won't work. With no audio input the led supply will be (zener voltage-0.6V), say 5.4V on a 12V supply, so 3 x 2V in series will be off, they'll come on with the positive-going side of a signal, the more powerful the brighter they'll be. Maximum led supply will be about 9.8V (from 12V supply); if you only want to run 1 bright led per channel you'll get a better dimming by mopping the spare voltage up with a couple of cheap hidden ones in series (or 6 diodes). Well, one set will pass bass, another mid-range and the other treble, so take your pick.
I have spent the past year developing something that will beat to music. Sure, maybe not as fun as making it yourself but still
Any of you guys see this? http://www.national.com/pf/LM/LM4970.html Three channel audio LED driver. Can program directly too.
