I'm new here so please be gentle. First of all two thumbs up for this forum!! Nice to know there are others out there who like tinkering with Boss boxes.
Recently i bought a Boss CEB-3 and since i have been working on my ODB-3 to try to improve a though i also give the CEB-3 a try.
It is the digital version and i cannot find any schematic on the mighty web. So i opened up the box and found 4 chips. One is the digital processor, the second one i do not have a clue and there are two chips which are marked 022B from JRC.
Some browsing led me to the conclusion that these are probably TL022 op-amps and there are not know for there high quality sound. They are also used the the GE(B)-7 for the gyrators where they seem to be less important since they are not directly in the audio path. But in this case i suspect at least one of them to be in the signal path since the wet-dry signal gets mixed somewhere.
So i thought of replacing these two with Burr-Brown OPA2134 op-amps and also replace the capacitors in the signal path with high quality ones. Hoping this will reduce the noise.
So now to my questions: - Are the 022B chips really TL022 chips? - Can I replace them with the OPA2134 chips? - Has anyone ever been tinkering with this pedal or the CE-5 (they seem to be roughly the same)? - Any tips/ideas?
Yes - these schematics are not available on the web. Not sure if the "JRC022B" is really a TL022,but it is a dual low power opamp. THe OPA2134 should be a direct replacement.
Replacing the opamps in the graphic EQ pedals is a pretty standard mod. Replacing caps with the same value in metallized polyester is also a standard mod.
Got any pics of the circuit board? Which version is it? The description at the home page might help you, either way , some of the other CE mods might be able to applied
Thanks, it is the CEB-3A version so the new one with a digital chip and mostly SMD component. Although some of the capacitors are old style. The main problem is finding out which capacicators are actually in the signal path and if they are SMD or not.
Modding Boss CEB-3 (or CE-5)
Posted - 12/17/2008 : 16:23:13
