Tube Amps / Music Electronics
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|previous: Dave Hi,
|10/4/1999 8:32 PM|
|Mark Hammer||Re: DOD 690 Chorus broke..|
Since all similar delay-based effects work by combining straight and delayed signal, it is common to find designs using a switching system that simply brings the delay signal in and out of circuit at the final mixing stage, without turning anything off or bypassing the effect overall. You can APPEAR to have turned the effect on and off, and nothing has changed (i.e., you still get straight signal only). I have a busted MXR Commande Series Flanger that does exactly that - the LED lights up appropriately, but damned if you get anything other than straight signal out of it.
So, to RG's list I would add "Check the switch and/or switch circuitry".
Given the age of the unit, it is also possible that the bias trimpot has drifted and the BBD chip is not getting the DC offset it needs to carry signal through.
There is an old Craig Anderton mod to this pedal which involves one component and extends the overall delay range into passable flanging. I'll see if I can find it at home. It was posted in DEVICE magazine 20 years ago.