EA trem build

Started by Wxllx1, October 06, 2018, 12:15:47 PM

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Wxllx1

This is my first pedal build. I got an EA trem kit from mammoth.  I am using this build doc from guitarpcb.com (https://guitarpcb.com/wp-content/uploads/2018/06/BD_EA-Tremelo-v3.pdf). The enclosure came pre-drilled with 6 holes on top for knobs, LED, switches:



The kit came with 3 standard LEDs, 1 bezel, 3 pots, 1 DPDT switch and 1 3PDT footswitch.



Based on the build doc, I'm a little confused. It came with the killswitch so I was planning on wiring it for the bypass buffer as diagrammed on page 3 of the build doc. But that uses a bi-colour LED, which the kit did not come with. I guess I'm planning on putting the blue LED in D2 and mounting that with the bezel in the lower right hole in the enclosure. The killswitch will go in the lower left hole, then the 3 pots above. I'll put one of the standard LEDs on the board in D1. Will this work?


Mark Hammer

If the state of a single-color LED tells you what you need to know about the pedal's state, then absence of a bicolor LED is not a hardship.

The one thing I would encourage you to be mindful of is the value of the current-limiting resistor used to adjust the brightness of the LED.  I gather the providers, and whoever drew up the schematic, made some assumptions about relative brightness of the green and red sections of the bi-color, because you will note that R12 and R16 are different values.