>"> Low output impedance and high load impedance.   
   > Therefore a small change in load impedance does not matter at all.   
   >   
      
   ** An idea used by lots of test equipment like scopes, VTVMs and modern DMMs. "   
      
   Hold on, this goes against one of my assumptions. (I THINK) That appears it   
   will work fine if the next stage is an FET, or a bipolar with a very smooth   
   hfe/Ic characteristic. However in practice the hfe can vary considerably   
   though the operating range.    
   As the input signal passes through this range the hfe variations would cause   
   changes in Ib, correct ? As such that would introduce nonlinearity in the   
   output of the following stage, no ?    
      
   That nonlinearity is obviously undesirable in instrumentation, or in the   
   instance when one wants to design audio equipment that uses less feedback.   
   Such low feedback designs are touted as sounding better. I don't have proof   
   but it seems that negating a    
   huge amount of open loop gain might cause some sort of difficult to measure   
   distortion or whatever.    
      
   Increasing speaker damping can be easily handled by a lower impedance source   
   feeding the outputs and drivers, but a voltage gain stage is a bit different   
   and that is what the feedback affects.    
      
   Maybe I put it wrong as I sometimes do. If so say so.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)