Federal Compressor mods/repair

Discussion in 'rec.audio.pro' started by The Federal, Aug 28, 2003.

  1. The Federal

    The Federal Guest

    My beloved Federal compressor (can you tell I like it?) has been
    intermittant for quite some time. I believe it needs a recap. It had
    nos tubes put in and they dont have allot of miles on them, so that's
    my conclusion. In addition I've allways wished that I could have some
    sort of alternate release (and attack) times as I often have to really
    fiddle to get the compression smooth. Does anyone have any
    recommendations for techs who are familiar with these units?
    Shameless self promotion encouraged.
    Thanks in advance for your replies here or to my email
    David Shuman
    am864u@TAKETHISBITOUThotmail.com
  2. Scott Dorsey

    Scott Dorsey Guest

    The Federal <am864u@hotmail.com> wrote:
    >My beloved Federal compressor (can you tell I like it?) has been
    >intermittant for quite some time. I believe it needs a recap. It had
    >nos tubes put in and they dont have allot of miles on them, so that's
    >my conclusion.


    I'd be more suspicious of connectors than caps if it's intermittent.
    When it is out, how is it failing? Does it go silent, does it get
    distorted, or does it just stop compressing?

    The tubes will hardly ever go bad.

    >In addition I've allways wished that I could have some
    >sort of alternate release (and attack) times as I often have to really
    >fiddle to get the compression smooth. Does anyone have any
    >recommendations for techs who are familiar with these units?


    I work on them occasionally but if you want adjustable attack and decay,
    you will probably wind up with a much sharper knee. Remember these
    things were intended as program compressors for voice applications, not
    as general purpose adjustable compressors. If you want something adjustable,
    use a different compressor.
    --scott
    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."
  3. The Federal

    The Federal Guest

    I posted a reply, but it seems to have disappeared, so hopefully I'm
    not repeating myself.

    The fault is excessive buzzing, almost like the noise floor when I
    turn one of the controls on the back (threshold and current) all the
    way up. It actually gets much worse. It is intermittant, sometimes
    shutting it off for a few hours does the trick. The strange thing is
    it usually is one way or the other, it won't start quiet and get noisy
    (as I recall). The audio can be distorted when it is acting up.

    I can live with it as is, I just thought I'd make an inquiry. I tend
    to use it more for it's tonal character than it's limiting ability
    anyway.
    David Shuman



    kludge@panix.com (Scott Dorsey) wrote in message news:<bilqg6$18o$1@panix2.panix.com>...

    > I'd be more suspicious of connectors than caps if it's intermittent.
    > When it is out, how is it failing? Does it go silent, does it get
    > distorted, or does it just stop compressing?
    >
    > The tubes will hardly ever go bad.
    >
    > >In addition I've allways wished that I could have some
    > >sort of alternate release (and attack) times as I often have to really
    > >fiddle to get the compression smooth. Does anyone have any
    > >recommendations for techs who are familiar with these units?

    >
    > I work on them occasionally but if you want adjustable attack and decay,
    > you will probably wind up with a much sharper knee. Remember these
    > things were intended as program compressors for voice applications, not
    > as general purpose adjustable compressors. If you want something adjustable,
    > use a different compressor.
    > --scott
  4. This is one of those obscure pieces that probably nobody in particular
    is going to know expertly, and documentation can be hard to find.
    Sounds like fun. E-mail me privately and we'll see if I can do the
    work for you.

    ulysses


    The Federal <am864u@hotmail.com> wrote:

    > My beloved Federal compressor (can you tell I like it?) has been
    > intermittant for quite some time. I believe it needs a recap. It had
    > nos tubes put in and they dont have allot of miles on them, so that's
    > my conclusion. In addition I've allways wished that I could have some
    > sort of alternate release (and attack) times as I often have to really
    > fiddle to get the compression smooth. Does anyone have any
    > recommendations for techs who are familiar with these units?
    > Shameless self promotion encouraged.
    > Thanks in advance for your replies here or to my email
    > David Shuman
    > am864u@TAKETHISBITOUThotmail.com
  5. Scott Dorsey

    Scott Dorsey Guest

    The Federal <am864u@hotmail.com> wrote:
    >
    >The fault is excessive buzzing, almost like the noise floor when I
    >turn one of the controls on the back (threshold and current) all the
    >way up. It actually gets much worse. It is intermittant, sometimes
    >shutting it off for a few hours does the trick. The strange thing is
    >it usually is one way or the other, it won't start quiet and get noisy
    >(as I recall). The audio can be distorted when it is acting up.


    Could be a bad paper capacitor but I'd suspect a ground gone bad
    somewhere first.

    If you change out the coupling capacitors, it will change the sound of
    the thing considerably. I think it will change it for the better, but
    you may not.

    >I can live with it as is, I just thought I'd make an inquiry. I tend
    >to use it more for it's tonal character than it's limiting ability
    >anyway.


    Get a tech to power it up and start tapping on things with a wooden rod.
    If it's a paper cap or a cracked resistor, it'll be VERY obvious when he
    find the offending part.
    --scott
    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."

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