DOD FX 91 Bass Overdrive: I found a factory flaw, R3

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Earthscum
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Joined: 19 Sep 2009, 14:39

Post by Earthscum »

Hey all. Figured I'd share this with everyone here, too. Whilst modding my not-so-lovely sounding FX 91, I kept having problems with filtering not working correctly. After doing a couple different mods, modding back, I discovered this little problem...

R3, the resistor from feedback to (cap) to ground SHOULD be 1k (brown-black-red-gold), however I discovered mine to be 200R!!! (red-black-brown-gold).

This one resistor takes the gain off the charts, and that's at over 6kHz! Freakin christ, no wonder I couldn't stand it. 1k in there gives the normal 720Hz corner frequency of a TS style circuit.

Before you mod or throw it, check that resistor. It makes ALL the difference in the world!

ETA: Serial number on mine is 670478. I'm entirely NOT sure how far this spreads. If a reel has 10,000 resistors, this could be a long run. I may email DOD and ask them if this is something they were aware of (I doubt it). If you have one, check the R3, and post your SN and if the resistor is correct... maybe at least track down a range to watch for.

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pablomago
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Joined: 04 Nov 2011, 12:10
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Post by pablomago »

I replaced the resistor in mine today. I'm not sure how much difference it made, but I didn't listen to it right before I changed it to compare. It was pretty easy to work on. It sounded pretty good with guitar. I'll try it out with the bass tomorrow. The S/N is 635790.

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