Dead DOD Supra Distortion FX55B

motion2freedom · Post by **motion2freedom** » 08 Oct 2012, 17:46

Hi. Just bought DOD Supra Distortion FX55B and accidentally connected it to a 18V power supply. So i don't really know if i've burnt it or was it delivered broken, but it doesn't work. The light turns on, but there's no sound except for a very quiet buzz when level/dist are set on max (when you pull the strings). Is it possible to determine what's broken, what equipment is required to do so? I can soldier, but am a total noob in fixing stompboxes. Any ideas what to do with it?

Ok, and it's not a battery/cable/guitar/amp problem for sure.

Thanks in advance for any feedback.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 09 Oct 2012, 08:41

dodfx55b_dist.pdf: (95.05 KiB) Downloaded 138 times

The opamps and other semi's should be able to handle that 18 volts easily. Therefore check first for electrolitic caps C15, C16 and C17 in the power supply circuitry for being of a lower rating than 18 volts. Use your nose. Leaking electrolits smell sour when leaking.

Get a multimeter and verify 9 volts where the schem says so and 4.5 volts at the bias points and at the outputs of opamps U1a and b as well as U2a and B.

Please post your results

motion2freedom · Post by **motion2freedom** » 09 Oct 2012, 11:54

Thanks for the reply.

I have ordered a cheap tester from ebay, should arrive in half a month. But it won't work with 4,5 V i guess.
Can't smell anything particular and can't find C15. I also don't know how to take the scheme out of the box.

So, waiting for the tester, i'll post the results of my investigation as soon as it arrives.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 09 Oct 2012, 16:22

C15 should be in parallel to diode D7 and connected to the DC jack.

What tester did you order that would not work with 4.5 volts? Assuming you've bought a multimeter it should work. Any multimeter is able to measure 4.5 volts.

motion2freedom · Post by **motion2freedom** » 09 Oct 2012, 18:46

i ordered this one
https://www.ebay.com/itm/Auto-Circuit-T ... 6602844%26

would this one fit?
https://www.ebay.com/itm/New-LCD-Digita ... 232358e834

Still can't find C15. I'll keep studying the schematics as i don't get much from it so far.

motion2freedom · Post by **motion2freedom** » 25 Nov 2012, 13:03

Gave it to a friend, they checked everything and said it works fine, so no one knows what was the issue, but it works now.
Great pedal btw, like it more than ds-2

motion2freedom · Post by **motion2freedom** » 25 Nov 2012, 14:10

no i was too excited about it, they just a bit different, cant say it beats ds-2)