• Mic preamp gain knobs

    From Tobiah@21:1/5 to All on Thu Feb 17 15:51:17 2022
    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead? What
    would the simplest solution be for substituting
    digital input for knob twiddling? I guess we're
    really tied to the analog world here. Aside from
    having a servo turn a pot, how could this be done?

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  • From Chris K-Man@21:1/5 to Tobiah on Thu Feb 17 17:48:44 2022
    On Thursday, February 17, 2022 at 6:51:28 PM UTC-5, Tobiah wrote:
    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead? What
    would the simplest solution be for substituting
    digital input for knob twiddling? I guess we're
    really tied to the analog world here. Aside from
    having a servo turn a pot, how could this be done?
    _____

    Well let me akse you this: Are there any issues with continuing
    to have a knob representation for input gain adjustment? I
    mean, it's what most folks are used to

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  • From geoff@21:1/5 to Tobiah on Fri Feb 18 16:25:11 2022
    On 18/02/2022 12:51 pm, Tobiah wrote:
    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead?  What
    would the simplest solution be for substituting
    digital input for knob twiddling?  I guess we're
    really tied to the analog world here.  Aside from
    having a servo turn a pot, how could this be done?



    Unlikey - the gain is near the front-end of the analogue circuitry,
    before the A-D, and it's purpose is to boost the signal to a level where
    the A-D can work optimally.

    geoff

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  • From John Williamson@21:1/5 to Tobiah on Fri Feb 18 07:37:18 2022
    On 17/02/2022 23:51, Tobiah wrote:
    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead? What
    would the simplest solution be for substituting
    digital input for knob twiddling? I guess we're
    really tied to the analog world here. Aside from
    having a servo turn a pot, how could this be done?

    On a lot of mic preamps, the amplifier runs constantly at full gain,and
    the level control limits the level it sees, helping avoid clipping. It
    may also actually alter the gain if the first stage. Normal practoce is
    to set the gain there at the start of the session, and then use your DAW
    to control levels in the mix.

    Controlling the preamp digitally adds complexity for no reason.

    Some microphones have a 10dB pad on the outpout for the same purpose.


    --
    Tciao for Now!

    John.

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  • From Ralph Barone@21:1/5 to Ralph Barone on Fri Feb 18 16:00:11 2022
    Ralph Barone <ralph@invalid.com> wrote:
    John Williamson <johnwilliamson@btinternet.com> wrote:
    On 17/02/2022 23:51, Tobiah wrote:
    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead? What
    would the simplest solution be for substituting
    digital input for knob twiddling? I guess we're
    really tied to the analog world here. Aside from
    having a servo turn a pot, how could this be done?

    On a lot of mic preamps, the amplifier runs constantly at full gain,and
    the level control limits the level it sees, helping avoid clipping. It
    may also actually alter the gain if the first stage. Normal practoce is
    to set the gain there at the start of the session, and then use your DAW
    to control levels in the mix.

    Controlling the preamp digitally adds complexity for no reason.

    Some microphones have a 10dB pad on the outpout for the same purpose.



    There might be some ideas here.

    https://www.diystompboxes.com/smfforum/index.php?topic=113226.0



    And it appears the old XIcor EEPOTs are discontinued, but you can maybe
    still buy something similar.

    https://www.renesas.com/us/en/products/analog-products/data-converters/digital-controlled-potentiometers-dcp/x9241a-quad-digital-controlled-potentiometers-xdcp-non-volatilelow-power2-wire64-taps

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  • From Ralph Barone@21:1/5 to John Williamson on Fri Feb 18 15:52:07 2022
    John Williamson <johnwilliamson@btinternet.com> wrote:
    On 17/02/2022 23:51, Tobiah wrote:
    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead? What
    would the simplest solution be for substituting
    digital input for knob twiddling? I guess we're
    really tied to the analog world here. Aside from
    having a servo turn a pot, how could this be done?

    On a lot of mic preamps, the amplifier runs constantly at full gain,and
    the level control limits the level it sees, helping avoid clipping. It
    may also actually alter the gain if the first stage. Normal practoce is
    to set the gain there at the start of the session, and then use your DAW
    to control levels in the mix.

    Controlling the preamp digitally adds complexity for no reason.

    Some microphones have a 10dB pad on the outpout for the same purpose.



    There might be some ideas here.

    https://www.diystompboxes.com/smfforum/index.php?topic=113226.0

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  • From pallison49@gmail.com@21:1/5 to John Williamson on Fri Feb 18 18:30:18 2022
    John Williamson wrote:
    ===================

    On a lot of mic preamps, the amplifier runs constantly at full gain,and
    the level control limits the level it sees, helping avoid clipping.

    ** Horse poo.

    Virtually all mic pres have variable gain.
    Typically from 5 times to 1000 times ( 14 to 60dB ).

    It may also actually alter the gain if the first stage.

    ** Noting "may" about it.

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  • From Scott Dorsey@21:1/5 to toby@tobiah.org on Sun Feb 20 23:52:59 2022
    In article <sumn1q$1lor$1@gioia.aioe.org>, Tobiah <toby@tobiah.org> wrote:
    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead? What
    would the simplest solution be for substituting
    digital input for knob twiddling? I guess we're
    really tied to the analog world here. Aside from
    having a servo turn a pot, how could this be done?

    These days most of the kids are working on crazy low voltage rails and
    using Maxim digitally-controlled pots. I strongly advise not using them
    inside the preamp feedback loop, though.

    The THAT 1580 digitally-controlled preamp IC is a very easy all-in-one solution, though, and cleaner than most of the standalone digitally-controlled pots.
    --scott
    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."

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  • From INFOHOU@21:1/5 to Tobiah on Sun Feb 20 21:55:46 2022
    On Feb 17, 2022 at 17:51:17 CST, "Tobiah" <toby@tobiah.org> wrote:

    My audio interface has one for each mic input.
    What would it take for a manufacturer to remove
    these knobs from the interface and have that
    value be controlled by software instead? What
    would the simplest solution be for substituting
    digital input for knob twiddling? I guess we're
    really tied to the analog world here. Aside from
    having a servo turn a pot, how could this be done?

    The Avid Carbon interface has pres that are controlable from withing Pro
    Tools. I believe I can do it with my UA Apollo through their Console app. The Apollo can also imitate various mic pres. However, the Carbon has better converters. Not sure my old ears can hear it, but the reviewers claim it. I definately noticed an increase in clarity on my main system (2019 Mac Pro with Genelec 8010As/sub) going to the Carbon from a MOTU M2, but I digress.

    Hope y'all have some fun,
    Robert

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