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    Scott Frankland interview from a few years ago on tubes & distortion

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    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Scott Frankland interview from a few years ago on tubes & distortion

    Post by deepee99 on Thu Jan 09, 2014 3:30 am

    Forgive me if posted elsewhere, but I recently came across a fascinating interview with Scott Frankland of MFA amplifier fame from 2001 on the topic of tubes, distortion, feedback, triode v. pentode operation, thought it might be of interest.
    It's from Issue 14 of Positive Feedback:
    http://www.positive-feedback.com/Issue14/franklandinterview.htm

    Would be interested to hear comments from others on this board far more conversant than me on such technical matters.

    GP49

    Posts : 717
    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: Scott Frankland interview from a few years ago on tubes & distortion

    Post by GP49 on Thu Jan 09, 2014 11:51 am

    > Pappas: Why the change to EL34's? There seems to be a huge power
    > penalty.
    >
    > Frankland: Because an EL34 amplifier has the potential for less
    > distortion than a 6550 amp.
    >
    > Pappas: What's so special about the EL34?
    >
    > Frankland: For one thing, the EL34 is a true pentode. The 6550 is a
    > beam tube. They have different conductance curves and therefore
    > different distortion characteristics. RCA and Philips carried on a
    > sophisticated debate in the '30s over which technology was better.
    > Although the 6550 can produce more power than the EL34, the EL34
    > needs less driver swing than a 6550 at any given power level. This
    > means less distortion contributed by the driver stage.
    >
    > Pappas: So you're going for lower distortion in this new amp?
    >
    > Frankland: I'm going specifically for lower high-frequency
    > distortion.

    Perhaps this is why I prefer the EL34 to the 6550 in my modified Mark II amplifiers, despite the lower power output (which amounts to very little anyway). I just like their sound better with the EL34.




    peterh

    Posts : 641
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Scott Frankland interview from a few years ago on tubes & distortion

    Post by peterh on Thu Jan 09, 2014 12:33 pm


    Vacuum Tube Valley Magazine seems unavailable at the URL.
    Do anyone know where to find it now ?

    GP49

    Posts : 717
    Join date : 2009-04-30
    Location : East of the sun and west of the moon

    Re: Scott Frankland interview from a few years ago on tubes & distortion

    Post by GP49 on Thu Jan 09, 2014 2:01 pm

    Issue One: http://vacuumtubevalley.com/Magazines/VTV01a.pdf

    Change the "01" to whatever issue you want.  Works through Issue 20.  How many were there, anyway?

    peterh

    Posts : 641
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Scott Frankland interview from a few years ago on tubes & distortion

    Post by peterh on Thu Jan 09, 2014 2:07 pm

    GP49 wrote:Issue One:   http://vacuumtubevalley.com/Magazines/VTV01a.pdf

    Change the "01" to whatever issue you want.  Works through Issue 20.  How many were there, anyway?
    Thanks.
    There was 20 issues i believe.

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Scott Frankland interview from a few years ago on tubes & distortion

    Post by deepee99 on Thu Jan 09, 2014 2:10 pm

    peterh wrote:
    Vacuum Tube Valley Magazine  seems unavailable at the URL.
    Do anyone know where to find it now ?

    Great reading, perhaps a bit ahead of its time.

    Here's an earlier thread on VTV, here on this forum:

    http://dynacotubeaudio.forumotion.com/t1621-vacuum-tube-valley-magazines-free-downloads

    peterh

    Posts : 641
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: Scott Frankland interview from a few years ago on tubes & distortion

    Post by peterh on Thu Jan 09, 2014 2:45 pm

    deepee99 wrote:
    peterh wrote:
    Vacuum Tube Valley Magazine  seems unavailable at the URL.
    Do anyone know where to find it now ?

    Great reading, perhaps a bit ahead of its time.

    Here's an earlier thread on VTV, here on this forum:

    http://dynacotubeaudio.forumotion.com/t1621-vacuum-tube-valley-magazines-free-downloads
    This link does not work for me, i get redirected to "http://www.jumpjet.info/#menu" where i cannot find any Vacuum Tube Valley Magazine(s).

    deepee99

    Posts : 1260
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Scott Frankland interview from a few years ago on tubes & distortion

    Post by deepee99 on Thu Jan 09, 2014 2:51 pm

    peterh wrote:
    deepee99 wrote:
    peterh wrote:
    Vacuum Tube Valley Magazine  seems unavailable at the URL.
    Do anyone know where to find it now ?

    Great reading, perhaps a bit ahead of its time.

    Here's an earlier thread on VTV, here on this forum:

    http://dynacotubeaudio.forumotion.com/t1621-vacuum-tube-valley-magazines-free-downloads
    This link does not work for me, i get redirected to "http://www.jumpjet.info/#menu" where i cannot find any Vacuum Tube Valley Magazine(s).

    Ditto here. This works: http://www.vacuumtubevalley.com/

    Edit: Click on an issue, then do a cut and paste on the URL to the .pdf file for that issue.

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