EA Tremolo - adding a blinking led

[Mexxx]

Hi! So I am building the EA tremolo from tonepad and there is a suggestion in the comments "added led between 12k resistor and collector of Q3- this gives you visual rate indicator".
This is the layout - http://www.tonepad.com/getFile.asp?id=130

Does it mean that I should add the led between the 12k resistor and the leg that is on the same trace or should I put it between 12k and the 2m2 resistor? In other words, does it matter on which side of the 2m2 resistor I add the other leg of the led?

Also, am I correct saying that the positive leg of the led should be connected to 12k and the negative to the transistor?

[Mark Hammer]

The information is here: http://home-wrecker.com/eatremolo.html

The "front end" of the ROG version is a little different, but the LFO and indicator LED can be directly generalized to the Tonepad schematic.

Note that the LED blinks "opposite" to the LFO.  That is, when the circuit goes from low to high volume, the LED goes dark and when the circuit goes low volume, the LED gets bright.  As long as you use the LED to simply provide a sense of "how fast", rather than using it so sync anythng to anything else, you'll be fine.

What I did on one of mine is place an additional 10k or 12k current-limiting resistor in series with the 10k shown.  When the effect is ON, I use the stompswitch to place a shunt across that added resistor, and when in bypass mode the switch lifts that shunt.  This lets the LED keep flashing the rate, but it flashes dim when in bypass and bright when in effect mode.  Since you have the visual indicator, you don't need any additional status LED to differentiate between effect/bypass.
Alternatively, you get one of those tri-color LEDs ( http://www.taydaelectronics.com/leds/round-leds/5mm-leds/rgb-led-5mm-common-cathode.html or http://www.smallbearelec.com/servlet/Detail?no=1229 ) and use the stompswitch to select between one flashing colour for effect, and another for bypass.

[Henry89789]

Mark Hammer: Thanks for putting up the link to the EATremolo schematic. That perfboard layout is great. I wish I could find one of those for all the pedals I want to build.