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Middle pot added


 :
8/19/1999 8:34 PM
Giacomo
 Middle pot added
I added middle pots to my SFDR. Now if I turn down ALL tone knobs to zero the volume goes to zero too. Is it normal or something is wrong?  
 
I replaced the 6.8k resistor with 10k pot wiring the same way you can see on other classic Fender amps.  
 
 
 
Giacomo  
 
  
8/19/1999 11:40 PM
tboy
Yes, Giacomo, that's normal.  
 
 
 
--tboy
  
8/19/1999 11:40 PM
old dr. fuzz
absolutely normal- any old fender with a midrange control will have no ouput when all tone controls are zeroed. Fender tone controls are passive, not active like a mixer or hifi. The  
 
Midrange actually affects all frequencies equally, like a fasder, and unless some tone control is opened no signal will pass. I found this out the hard way playing at the minnesota state fair in 1965. Our garage band got a chance to play on the big stage with "real" equipment and I plugged into channel two of a dual showman. I kept turning up the volume- but no sound. Finally the mc came over and dimed everything! LOTS OF SOUND THEN!
 
8/20/1999 1:23 AM
Steve A.
odf:  
 
 
 
any old fender with a midrange control will have no output when all tone controls are zeroed.  
 
 
 
    The 5F6A tweed bassman is one exception, but most people call that a Marshall-style tone stack these days...  
 
 
 
Steve Ahola
  
8/22/1999 2:34 PM
Trace
quote:
"The 5F6A tweed bassman is one exception, but most people call that a Marshall-style tone stack these days..."
 
 
 
 
Good point Steve! I think it's because Marshall still uses it and Fender sort of "dropped" it a little while back.  
 
 
 
Giacomo....You could always replace the 10K Mid Pot with a 25K for more flexibility.  
 
 
 
Trace  
 
  
8/22/1999 6:17 PM
C.C.
Why would the tweed /marshall not kill the volume?I thought the tone circuits were the same except location and values.
  
8/22/1999 6:34 PM
Steve A.
C.C.  
 
 
 
I thought the tone circuits were the same except location and values.  
 
  
 
 
 
    With the BF stack the mid cap connects to the "top" of the mid control (where it is connected to the bass control); on the Marshall-style stack, the mid cap connects to the wiper of the mid control. As to why it should operate differently... I better leave that one to the experts!  
 
 
 
Steve Ahola
  

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