94be8dbf   
   From: IanIveson.home@blueyonder.co.uk   
      
   Patrick Turner wrote :   
      
   Perhaps the original poster needs to learn to bias his amps   
   but for   
   that a brain which can understand basic electronics is   
   required. But I   
   have found by experience that musicians are artists who may   
   find it   
   easy to play a tune I find difficult but they really   
   struggle with   
   basic logic or the slightest technical issue. Not one guitar   
   amp   
   manufacturer has ever put a musician proof biasing scheme   
   under the   
   chassis of their creation. Shame on Fender and Marshal.   
      
      
   ***Surprising. Why not? It's a while since I've seen a new   
   guitar amp, but I would have thought some of them might have   
   made an attempt by now. Surely they're full of DSP and   
   SS-controlled switching these days? I'd kind of assumed that   
   an intelligent amplifier would look after itself.   
      
   ***I'm in the process of adding automated bias adjustment to   
   my amps, which is why I'm moaning about tiny SMT components.   
   The remote-controlled pre uses an MCU capable of running a   
   small country, so it might as well make itself useful. Since   
   the controller also handles power-on and power-off   
   sequencing, bias adjustment should fit in neatly, leaving   
   the digital circuits dormant when the amp's in use. It'll   
   wake up for the usual remote functions like volume control   
   and source select, or for alarm conditions such as an   
   out-of-range bias current. Otherwise it's non-invasive.   
      
   ***If anyone's interested in sharing what I've done and   
   helping put it to good use, BTW, let me know. PCB design,   
   and finalising the analogue part of the bias circuit, are   
   the main source of angst ATM, in addition to the SMT issue.   
   It's a good vehicle for learning about MCUs, digital   
   circuits, and programming. I hope. OTOH, that's not what ppl   
   are here for, I guess.   
      
   ***The other big thing for the future-if-there-is-one is   
   switch-mode power supplies for HT and heaters. Too scary for   
   me to experiment with. Books may aid the understanding, but   
   they don't seem to stop the smoke.   
      
   Ian   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)