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Pedal modding questions, experts have a look


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I bought an old DOD fx50 overdrive preamp at a pawn shop today cheap to mess around with. It has a chip marked tl022cp that has four prongs on either side. I have switched the chip in a rat pedal to put in a lm308n in that pedal. Can I do this kind of mod with this pedal? Any guides to what chips can be replaced with?

 

The lm308n added a more grittier sound to the rat, and I would like to do that with this pedal or give it some more low end.

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The TL022 is a dual low-power op-amp. It is common in mass-manufactured pedals, known to be used for controlling rate/depth of clock drivers in modulation pedals. It draws little current, which is a good thing in LFO circuits. But it is probably used in the DOD overdrive due to its low power consumption.

 

You can use any dual op-amp - JRC4558, TL072 etc. Changing the TL022 will probably provide higher amplification and less noise as well - bonus :thu:

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Thanks guys, I found a small article about changing the capacitor. I changed the only capacitor in the pedal from a 47 uf to a 470 uf, because I read the higher the value the more bass response. I haven't got to mess with it much more.

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Socket it with one of these and swap em in and out.




You can get better ones from smallbear with a few IC chips as well.


~Aaron

 

 

 

 

This. Have fun, go to radio shack and buy a few chips. Swap them in and out to see what you like the most. I did this with my GGG tube screamer and can't remember what I settled on, but they were all different. I'll have to go double check now because I'm curious.

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I changed the only capacitor in the pedal from a 47 uf to a 470 uf, because I read the higher the value the more bass response.

 

 

There's a few caps in that pedal, and I don't think that's an interesting one. Looking at the FX50B, that one has almost flat response except for a tone control network, but no one seems to have an FX50 schematic. Its probable basis in the 250 and the MXR Dist+ would indicate a .047 or .05 cap connected to pin 2 or 6 of the IC, leading towards the gain control, as a primary bass roll-off, but only as gain is increased.

 

You can try randomly swapping around tone parts but knowing how it works is a lot better.

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