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stinkfoot
Silver Member
Sweden
181 Posts |
 Posted - 04/06/2009 : 16:39:18
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Hi everybody (and especially the Boss delay crowd)! I have a problem child on the bench right now, and just can't seem to figure it out. It's a DD-3 version 1 (with the DD-2 circuit) that just has too much delay. Everything works as it should, but for some reason the delay (with the echo level knob set at 12 o'clock) is quite a bit louder than on other similar pedals. Also, the feedback is a bit crazy - it starts oscillating wildly even with the feedback knob at 12 o'clock...
I assume the feedback issue is related to the main delay signal being too strong, but I don't have a clue where to start looking. I'm thinking it could be somewhere in the compander area, where the main signal and feedback return joins up, but that's just a wild guess.
/Andreas |
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Dr. Bob
Moderator
Australia
6593 Posts |
Posted - 04/06/2009 : 17:37:14
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Hi stinkfoot - Andreas
has the pedal been worked on before?
Check the value of the Pots, see if they are the correct value.
Check the pedal wasn't dropped & banged on the shafts of the post/ or the pots were stood on.
This can sometimes make the wiper go open or intermit.
I have seen DD-x's where the owner has messed with the trim pots.
Check the NE570 - IC2
Check the 4066 - IC4, I have replaced a heap of flaky-faulty 4066's in the past year,
not necessarily in DD-x's, but in general.
Look for cracked open tracks near the edges of the PCB.
Broken wire from the Pot/s to the main PCB?
Did anything really obvious happen to this unit? that you are aware of, or that shows?
For now, I don't know what else to suggest, it's late here. 
Regards Dr. Bob 
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Edited by - Dr. Bob on 04/06/2009 17:38:24 |
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stinkfoot
Silver Member
Sweden
181 Posts |
Posted - 04/06/2009 : 19:27:01
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From what I could see, it seemed virgin enough, and all the pots work just like they should. Stupidly, I didn't try the pedal out before I took it apart to be modified. I usually test every pedal before doing anytyhing else, just to verify that it works properly, but not this time. Of course...
I only added a LP filter to the mixer section, though, so I doubt it's something I did. I've e-mailed the owner to ask if he recognizes the behaviour, and will also remove the filter to see if that changes anything. But it does really sound like the delay circuit is being hit with a harder signal than it's supposed to - the repeats have a little hair on their chest, like they're clipping a little.
Thanks for the tips - I'll head up to the workshop in a while, and start looking :D
/Andreas |
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Weird DD-2/3 problem - too much delay...
