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output stage topology

Discussion in 'Pro Audio Equipment' started by chrissugar, Aug 22, 2003.

  1. chrissugar

    chrissugar Guest

    Hi Sebatron

    I have a technical question for you. I would like to ask what topology you used for the output stage of your preamp and why. SRPP, White cathode follower or other?
    Every topology has its pros and cons so if it's possible I would like to know your philosophy.
    Thank you.

  2. Sebatron

    Sebatron Well-Known Member

    Dec 22, 2002
    I tried lots of configurations with the output stage.
    Transformers were ok … but lacked the transparency that I was chasing.
    I wanted a tight clean circuit with lots of headroom….with only the colour from the active gain component…the valve…and input transformer.
    Especially tight in the lower register ….transformers can be lumpy and untrustworthy here…

    The other problem I found with transformer based buffer output is insertion loss. To get the equivilent gain that I get out of the vmp circuit would’ve meant adding an extra gain stage or tube which would’ve slowed transient response and narrowed dynamic range, raised the noise floor etc.
    I got round all these problems with my phase splitter/cathode follower circuit.
    There’s virtually no gain loss.
    It is basically a phase splitter followed by two cathode follows for the full balanced circuit.
    This runs on a 60 volt d.c single rail.
    This circuit is my ‘winged keel’.
    My lawyer may sue me if I release any more details. :w:
  3. chrissugar

    chrissugar Guest

    Thank you very much!


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