Corrections to May's SRPP
Subject: I can't get the correct result
    Thank you for your effort on the best webzine devoted to tube circuits! I've learned much more from it than elsewhere, and pray you never stop.
    I read the issue of May 2000 carefully, and one calculation confuses me, I can't get the same answer as yours from the formula of
:
Best regards!

Gm“=

                          mu

Ra + rp + [(mu + 1)Rak + rp][(Rak)||Rl]
                                      rp + Rak

Chen

    Thank you for the kind words and thanks for spotting the typo. I have updated May's issue. The correct formula is as follows:

Current flows for the SRPP amplifier

Conclusion
   The SRPP circuit is more complex than first imagined. Careful scrutiny of its workings reveals that it is not as universal an amplifier as we would want, but by designing with the load in mind, we can optimize the circuit for that load.

                              // JRB

Gm“=

                          mu

Ra + rp + [(mu + 1)Rak + rp][(Rak+rp)||Rl]
                                      rp + Rak

  Audio Gadgets is software for the technically minded audiophile. The quickest way to understand what Audio Gadgets is all about is to imagine a programmable calculator designed for the audio enthusiast. Audio Gadgets does far too much to fit in even a 21" monitor; consequently, the notebook metaphor is used to hold ten pages of audio topics. Stepped attenuators to tube circuits.             
           
             
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Shown above is the RIAA EQ page, which is only one of ten audio pages.

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