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push pull front end (again)

12/16/2003 10:47 PM
push pull front end (again)
a while ago there was a thread here about using a balanced design. someone mentioned driving a push pull input stage straight from the guitar without a phase inverter. i was wondering if you could do this without changing the wiring in the guitar, and would it be a safety hazard if the guitar is not grounded?
12/17/2003 12:55 PM
you cannot do it without modifications to the guitar itself. you need a balanced signal output from the guitar, which mandates either a phase splitter on board, or a pickup that has a +, -, and ground connections. obviously you will also need a three conductor cable.  
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12/17/2003 5:44 PM
Sounds like a cool op amp application. Not in the guitar though - better to do it at the amp front end.  
You could power the op amp(s) with the heater supply.
12/17/2003 6:04 PM

It can also be done with a bal-un xfmr.  
12/17/2003 7:20 PM
andy fuchs

I always thought a centertapped pickup coil into a balanced input circuit would be wicked-cool.
12/18/2003 3:44 PM

"I always thought a centertapped pickup coil into a balanced input circuit would be wicked-cool."
Is that how Les Paul set up his personal guitars? I know he says he uses "low impendance pickups," and he needs to run a preamp in front of his regular amp because of it.  
Gibson had a model of Les Paul for a couple of years that had the same sort of pickups, but it didn't sell too well. I think it was the Artist series.  
12/17/2003 8:19 PM

why would you need a center tap? couldnt you just RC couple the signal end to the grid of one tube and the ground to the grid of another tube?  
what am i missing here?
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