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Vintage threads from the first ten years
help my dying BOSS ce2 chorus
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 4/1/1997 8:56 PM |
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j krogh |
help my dying BOSS ce2 chorus my chorus,over the last few months has been dying slowly,lately, even with a new battery,the effect is VERY subtle and transparent even with the controls on full,the effect is almost transparent,although the clean signal is coming through fine. can someone advise a trouble shooting to find the problem here?what is the first thing to look for?what component over a period of a few months could cause the wet signal to deteriorate. please help thank you |
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| 4/2/1997 12:50 AM |
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| Mark Hammer |
I don't know the CE-2 in particular, but from your description I'd start looking for some kind of trimpot on the board that has drifted. Many BBD delay chips require use of a trimpot to adjust a bias voltage going into the chip, or a trimpot to balance the two anti-phase outputs of the chip. If you've ever tweaked one, you'll realize that the effect quickly vanishes as you move from the "sweet spot" on the trimpot. There are probably more sophisticated and precise ways to do it, but you can probably count on the basic design principle that the mid-point of a trim-pot's rotation should be roughly where the default setting of the trim-pot should be. If, in fact, there is/are one or two trimpots on your CE-2 board, gently adjust the trimpot while playing, and listen for the sweet spot. It's probably helpful to have the external controls set for the most in-your-face sound, so you can more easily notice changes in sound as the trimpot gets moved. Once you've accurately located the sweet spot, you might want to hold the trimpot setting in place with nail polish, some hot or white glue, or what not. A second possibility is that the depth control has lost its reliability in some manner. Try a shpritz of contact cleaner in the depth control. Anyone else have any ideas? |
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| 4/3/1997 9:59 AM |
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| CJ Landry |
Thats a hard one to troubleshoot w/o a scope. Boss uses a voltage divider network for a Vref on their op-amps. Check that for 4.5vdc. Also, an oscillator check is another big question. Make sure your ground is good from the input to the pc-board and to the output. Good luck, and let me know if you want it fixed. Christian |
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