Hi guys, first post here ;D
I've built a lot of pedals with Brians excellent fabbed pcbs, and the collosalus is the first one giving me problems...
Well, I put it together today and everything went smoothly until I hooked it up to my testing rig. There was a loud, constant hum with no guitar signal coming through and the regulator got really hot until after about 30 seconds when everything suddenly went silent... Turns out I have fried a 4558 (ic2) which I had put in backwards ::) so now after replacing the IC, there is an audible sweep that sounds about right but it is accompanied by an annoying oscillation on the bottom of the sweep that can't be dialed out with the trimpots. Also, the clock trimpot behaves rather strangely as I cannot seem to find a position where the sweep is somewhat symmetric until the very end of the dial, but even them it is still not enough.
After double checking all the component values, the big question is: what else could have been damaged by reversing IC2?
Edit: btw I used 1n5817 for d4 and d5 as well as 100uf for c26 as per the doc, and 47pf for c22
Hi, did you solve problem? I have same problem with mine build.
it doesn't matter the board is damaged... I tried to change few parts and I've burned the board..
no, gave it up :'(. I guess BBD projects aren't for me. Sucks that you damaged the board though, maybe you can try and save the board by bridging the traces?
A little update for anyone experiencing noise even with the suggested caps/diodes: I just bought a 12v supply as a last resort in trying to make my Collosalus usable, and the clock noise is all gone :D I love this thing now!
I have manage to save the board!!! ;D and same thing with me I've also bought 12V supply and there is almost no noise.