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previous: GFR Re: Paraphase invertor instead of the long tailed. What -- 12/28/2000 10:39 AM View Thread

Re: Paraphase invertor cancellation

12/28/2000 5:02 PM
dpcoyle
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Re: Paraphase invertor cancellation
IMO Woody is 100% correct. The harmonics are not cancelled; they are not generated.  
 
 
 
The Williamson is said to use the paraphase for its ideally symetric behavior (in the tube's linear range), but then follows with a diffpair. This brings another gain stage, common mode rejection and symetrical distortion behavior as it craps out. I think this is where the differnce lies between the sound of the two stages, in overload.  
 
 
 
The paraphase has the ability to drive the power tube fed by the cathode follower leg far deeper than the leg that is driven by the high source Z of the other, plate-driven tube. At the onset of overload, this means one output tube gets bad signal before the other. 2nd order distortion is generated.  
 
 
 
All this assumes you have a set up where the driver stage distorts before the output stage, which IMO is bad design.  
 
 
 
Dan

 
Replies:
Woody C Dan,I feel like a d... -- 12/28/2000 8:00 PM