EASY way to power tube audio projects

Discussion in 'rec.audio.pro' started by OvrReactor, Sep 2, 2003.

  1. OvrReactor

    OvrReactor Guest

    For the past year, I’ve been making regulated linear power supplies for my
    own audio projects AND for sale to others. For most audio projects, a
    regulated B+ is overkill, so I’ve been installing a jumper across the
    regulator section of my PC boards and making a few plain old low tech, saggy B+
    supplies, and they have worked out great. Now that I’m happy with them,
    I’ve decided to gear up for production on these and add them to my power
    supply product line.

    I have two versions. The “high voltage†model can easily power up to four
    12AX7’s with at least 300 V. The “low voltage†supplies half the voltage
    but double the current, so it’s ideal for subminiature and 6922/6DJ8 designs.
    Each can supply up to 5 Watts of power and produces less than 10 mV p-p of
    ripple when fully loaded. FR107 Fast recovery rectifiers are used, and has a
    CR section filter included onboard. Jumper selectable for 120 / 240 VAC input.
    Board dimensions are 3.8" x 2.5".

    I have posted transfer curves and data tables on my website at
    http://members.aol.com/ecc81.

    The high voltage version (LDF5-320) has the following specifications;
    * 357 Volts (minimum) output unloaded, with 110 / 220 VAC (low line) input
    * 250 Volts (minimum) output at full load, with 110 / 220 VAC (low line) input
    * Can supply up to 17 mA, at full load
    * Height is less than 1.375" (fits in 1U rackmount chassis)

    The low voltage version (LDF5-160) has the following specifications;
    * 188 Volts (minimum) output unloaded, with 110 / 220 VAC (low line) input
    * 120 Volts (minimum) output at full load, with 110 / 220 VAC (low line) input
    * Can supply up to 35 mA, at full load
    * Height is less than 1.5" (fits in 1U rackmount chassis)

    Just to give you some idea of how to apply one of my power supplies to a
    typical design, assume that you want to power a circuit that has a pair of
    12AX7 tubes in it. You know that you want your B+ to be 300 V, and that the
    circuit draws 6 mA. Refer to the transfer curve (on my website, and included
    with the power supplies), and notice that when the line voltage is 115 VAC, the
    power supply will provide about 335 V at 6 mA. So to drop the 35 V, externally
    add a 5.6K Ohm 1/2 W dropping resistor followed by a 22 uF 450 capacitor and
    you’re DONE.

    I’m asking $32 each, plus shipping, for these power supplies.

    OR, buy one LDF5-160 or LDF5-320, AND one of my linear regulated filament
    supplies (PS6VA-6 or PS6VA-12), for $60 shipping included. (Shipping address
    must be in the US48, offer good through September 30, 2003.)

    And if you plan to scratch build a tube mic pre, buy one LDF5-160 or LDF5-320,
    AND one PS6VA-48 (regulated phantom power supply) AND a linear regulated
    filament supply (PS6VA-6 or PS6VA-12) for $90 shipping included. (Shipping
    address must be in the US48, offer good through September 30, 2003.)

    Sales can be prepaid by credit card through PayPal. If you have any additional
    questions that my website can’t answer, or if you want to buy some power
    supplies, please respond BY EMAIL to <OvrReactor@aol.com>, DO NOT POST. And
    please include your shipping address in your email.

    Regards,
    Tom Mitchell
    website - http://members.aol.com/ecc81
    website - http://www.over-reactors.com

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