Gentlemen, what in your opinion would be a proper place to introduce a blinking "rate" LED in an LFO from this schematic?
http://www.hollis.co.uk/john/easyvibe.jpg

All current attempts upset the bias (you can see how it's done on the schematic) and thus kill modulation completely. For instance when I parallel the optoisolator LEDs with one more (for indicator).
Maybe I should bias the LFO separately with a trim pot?
Or I should do that with LDR's?

Thank you.

You could connect the gate of a n-channel MOSFET to the output of the op-amp in the bottom right-hand corner (outer lug of the rate pot connects to this output) and stick the LED + current limiting resistor in series between V+ and the MOSFET's drain (source is grounded).  If you use a diode to connect the gate (cathode to op-amp's output, anode to gate) you can have a flashing Millennium (enables you to turn it off when bypassed).

That flashing LED Ansil put up with the 555 timer, I've been wondering about the application of those circuits to LDR based phasers, tremolo's etc.
 I don't see why they wouldn't work, not knowing how fast LDR's react I can't speculate whether flashing would be cool or not in given applications compared to a pulsing LED.
 The fact that there is such a low parts count caused me to speculate about more than one timer and flashing LED..Per LDR.  This would allow settings that would diminish greatly the cycling of up down up down up down, and make a more complex cycle of something like up halfway down half way back up, all the way down up a little etc....because at some points in time [as set by the rates of the two separately timed flashing LED's] the LDR would be seeing the lumens of 0, 1, [the other], or Both LED's.
 I haven't messed with it enough to say, posted a bit about it here before, was hopeing someone more experienced in such matters would catch on to the idea and say something like: "might work, but...", or "the timer will click unless it's on a different supply", or Flashing LED's will cause too sharp a rise and fall in resistance in the LDR....any takers???
 I keep going back to this one cause it seems like a good application for the Timer cct, ...I'm too lazy to experiment with it, ...I don't know that I have suitably R Ranged LDR's, or all of the above @A@ :shock: