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true bypass vs 50W plexi!!!


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10/5/1999 3:52 PM
benoit stoll
 true bypass vs 50W plexi!!!
hi, i did change my old Jen wah wah to true bypass a few months ago, it was ok with my old fenders... but since i got a 50W marshall plexi, it produces a big PLOP when i  
switch my wah on... and not when i switch it off... must i take it back to its original bypass?? or maybe some of you could help solve the pb... the true bypass was made ith the two resistors that i though was there to avoid the PLOP pb...  
thanx for all  
ben
  
10/5/1999 6:09 PM
R.G.
Pops and clicks when switching are almost always caused by switching to different DC levels.  
 
If the true bypass worked fine with a Fender and pops with the Marshall, it is likely that the Marshall has a DC level on its input. The pulldown resistors in a true bypass setup only guard against the EFFECT having DC leakage on its input or output. If the amp has leakage, it can still pop when you connect the amp to the effect.  
 
The only reason there is an "almost always" in the first statement is that rarely there will be a burst of oscillation from something when switching. I know this can occur, I've never really seen it.
  
10/5/1999 6:41 PM
Aron
R.G.,  
 
Any cure for this problem? I have heard that a number of pedals converted to true bypass were popping on a small Fender Deluxe but not on other amps.  
 
How do you get rid of that DC level on the input of the amp?  
 
Thanks,  
 
Aron
  
10/5/1999 11:22 PM
R.G.
You gotta find out what's putting the DC out of the amp. Could be a leaky tube, could be some oddity about the bias.  
If you capacitor couple at the amp input and put a pulldown on the outside, that will almost certainly fix it, but most people won't like that.
  
10/6/1999 5:56 PM
Don Symes
Is the grid-to-ground resistor connected on the plexi input?
  
10/6/1999 10:07 PM
R.G.
 Worst thing you can do to a guitarist
This discussion reminds me of a tip I got from a female acquaintance. The worst thing you can do to a guitarist is to take clear nail polish and paint the tips of all his guitar cords.
  
10/7/1999 10:24 AM
GFR
I thought the worst thing you can do to guitarist is to put some sheet music in front of him :)
  

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