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DIY Stompboxes => Building your own stompbox => Topic started by: keto on June 12, 2010, 05:22:39 PM

Title: EA Trem - Assistance Requested
Post by: keto on June 12, 2010, 05:22:39 PM
ROG modified EA Trem, based on this layout http://home-wrecker.com/eatrem-pcb.pdf (http://home-wrecker.com/eatrem-pcb.pdf) though I did move a few things around to try and tighten it up.  Suspect my error is in there somewhere, but I've been over it and over it and don't see the forest for the trees.

The 'boost' portion of the circuit works fine, so it's past there somewhere.  LED lights up, but doesn't pulsate.  FET's and transistor are DEFINITELY oriented correctly.

Parts substitutions:  R5 = 100E + 100E = 200E (measuring about 190E), in place of 180E.  R6 = 1K + 22oE = 1K22 in place of 1K2.  R14 = 12K1 + 2K67 = 14K77 in place of 15K.  No other subs, 1uF caps are obviously non polarized.

Board top:
(http://img.photobucket.com/albums/v374/keto/Pedal%20Builds/EATrem.jpg)
Circuit:
(http://img.photobucket.com/albums/v374/keto/Pedal%20Builds/EACircuit.jpg)
Circuit, with mapping details:
D1, D2 & D3 are a little hard to read, down near the bottom center - refers to Depth pot.

**I have C4 labelled/diagrammed wrong, + to R5, - to D of Q2
(http://img.photobucket.com/albums/v374/keto/Pedal%20Builds/EACircuitMap.jpg)

See anything I'm not seeing?  Thanks for looking :)
Title: Re: EA Trem - Assistance Requested
Post by: R.G. on June 13, 2010, 10:30:13 AM
One of the most effective ways of dealing with first-time circuit bringups I've ever found is written up here:
"Debugging thread: what to do when it doesn't work"

I suggest you read that.