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• Hi Xaudiomanx - 1973shovel 04:50:51 12/29/18 (0)
  In Reply to: RE: Looks to be Dave Gillespie's "Enhanced Fixed Bias" circuit... posted by xaudiomanx on December 28, 2018 at 16:08:34

  As Steve O and Triode Kingdom have said, and as I suggested in our private correspondence, the EFB is regulated bias, but it isn't as simple as "just" regulated bias.
  
  Also as they suggested, you may want to take a second look at Gillespie's article from that link I sent you last week, and re-read pages 5 through 8. I think you'll find it informative as to what his circuit does. The EFB schematic alone doesn't tell the whole story. (link to article below)
  
  
  "Suddenly, I'm not half the man I used to be. 'Cause now I'm an amputee" J. Lennon
  

  • Improving Dynaco's SCA-35 & ST-35   (Open in New Window)

  
  

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• RE: Looks to be Dave Gillespie's "Enhanced Fixed Bias" circuit... - Triode_Kingdom 19:20:25 12/28/18 (0)
  In Reply to: RE: Looks to be Dave Gillespie's "Enhanced Fixed Bias" circuit... posted by xaudiomanx on December 28, 2018 at 16:08:34

  The LM337 applies a regulated voltage to the cathodes. Because the adjustment is between ground and B+, variations in B+ are transferred to the regulated output, helping to stabilize current through the tubes when B+ varies. As stated above, this is all explained in great detail on Dave Gillespie's site.
  
  
  
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