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Re: SSM 2019/ INA217/INA163 circuit for AT853s

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  • dayVel
    You may still want to use an instrumentation amp, though. (I think I was a bit hasty in my reply.) If you want to make your input stage a variable gain stage,
    Message 1 of 7 , Sep 30, 2005
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      You may still want to use an instrumentation amp, though. (I think I
      was a bit hasty in my reply.)
      If you want to make your input stage a variable gain stage, the
      insrumentation amp may be a better choice. While it may seem simple to
      stick a variable resistance in the opamp's feedback loop, when you
      start to optimize the circuit for best noise performance, stuff starts
      getting real tricky real fast. Gain setting with the instrumentation
      amp is really straightforward.






      --- In micbuilders@yahoogroups.com, "Brian Dasilva"
      <bdasilva.rai@e...> wrote:
      > Thank you.. sigh.
      > You are right... kinda opamp looking the way they are drawn. Its what I
      > have... low parts count... again thanks
      >
      > -----Original Message-----
      > From: micbuilders@yahoogroups.com [mailto:micbuilders@yahoogroups.com]On
      > Behalf Of dayVel
      > Sent: Friday, September 30, 2005 10:59 AM
      > To: micbuilders@yahoogroups.com
      > Subject: [micbuilders] Re: SSM 2019/ INA217/INA163 circuit for AT853s
      >
      >
      > That's sounds right if you're doing this unbalanced. (Just to be
      > clear, the 10k resistor to ground should be on the amp side of the
      > coupling cap.) But the 2019 and similar chips like the INA217, INA103,
      > and INA163 aren't opamps, they're instrumentation amps and are really
      > more appropriate for doing simple balanced input circuits. If you are
      > going to do this unbalanced you may be better off using a simpler and
      > cheaper opamp-based circuit.
      >
      >
      > --- In micbuilders@yahoogroups.com, "Brian Dasilva"
      > <bdasilva.rai@e...> wrote:
      > > oh help... So i power my mic capsules (at853).. signal line comes
      > thru the
      > > 2.2uf blocking cap and into the opamp input with a 10K pullup to
      the +9v
      > > that I power my mics with and a 10K pull down to ground... The other
      > input
      > > to the opamp is grounded. (???) Yes with the resistor and inductor...)
      > >
      > > -----Original Message-----
      > > From: micbuilders@yahoogroups.com
      [mailto:micbuilders@yahoogroups.com]On
      > > Behalf Of dayVel
      > > Sent: Wednesday, September 28, 2005 12:32 PM
      > > To: micbuilders@yahoogroups.com
      > > Subject: [micbuilders] Re: SSM 2019/ INA217/INA163 circuit for AT853s
      > >
      > >
      > > Just use the circuits in the TI application notes. Make sure you use
      > > the suggested paralled resistor/inductor on the inputs.
      > >
      > >
      > > --- In micbuilders@yahoogroups.com, "Brian Dasilva"
      > > <bdasilva.rai@e...> wrote:
      > > > I need to build a small (well X2 9v batterys + circuit) The data
      > > sheet tells
      > > > most... Richard tells more... Any cookbook circuits out there?
      > >
      > >
      > >
      > >
      > >
      > >
      > > Yahoo! Groups Links
      >
      >
      >
      >
      >
      >
      > Yahoo! Groups Links
    • Brian Dasilva
      I figured a set of headers with 4 values of fixed gain 10db 20db... that you could choose with a plastic shunt... And another jumper to turn on power... No
      Message 2 of 7 , Oct 1, 2005
      • 0 Attachment
        I figured a set of headers with 4 values of fixed gain 10db 20db... that you
        could choose with a plastic shunt... And another jumper to turn on
        power... No pots, no switches.. Decent specs and several drop in pin
        compatible chips for different "sounds"

        -----Original Message-----
        From: micbuilders@yahoogroups.com [mailto:micbuilders@yahoogroups.com] On
        Behalf Of dayVel
        Sent: Friday, September 30, 2005 11:15 PM
        To: micbuilders@yahoogroups.com
        Subject: [micbuilders] Re: SSM 2019/ INA217/INA163 circuit for AT853s

        You may still want to use an instrumentation amp, though. (I think I was a
        bit hasty in my reply.) If you want to make your input stage a variable gain
        stage, the insrumentation amp may be a better choice. While it may seem
        simple to stick a variable resistance in the opamp's feedback loop, when you
        start to optimize the circuit for best noise performance, stuff starts
        getting real tricky real fast. Gain setting with the instrumentation amp is
        really straightforward.






        --- In micbuilders@yahoogroups.com, "Brian Dasilva"
        <bdasilva.rai@e...> wrote:
        > Thank you.. sigh.
        > You are right... kinda opamp looking the way they are drawn. Its what
        > I have... low parts count... again thanks
        >
        > -----Original Message-----
        > From: micbuilders@yahoogroups.com
        > [mailto:micbuilders@yahoogroups.com]On
        > Behalf Of dayVel
        > Sent: Friday, September 30, 2005 10:59 AM
        > To: micbuilders@yahoogroups.com
        > Subject: [micbuilders] Re: SSM 2019/ INA217/INA163 circuit for AT853s
        >
        >
        > That's sounds right if you're doing this unbalanced. (Just to be
        > clear, the 10k resistor to ground should be on the amp side of the
        > coupling cap.) But the 2019 and similar chips like the INA217, INA103,
        > and INA163 aren't opamps, they're instrumentation amps and are really
        > more appropriate for doing simple balanced input circuits. If you are
        > going to do this unbalanced you may be better off using a simpler and
        > cheaper opamp-based circuit.
        >
        >
        > --- In micbuilders@yahoogroups.com, "Brian Dasilva"
        > <bdasilva.rai@e...> wrote:
        > > oh help... So i power my mic capsules (at853).. signal line comes
        > thru the
        > > 2.2uf blocking cap and into the opamp input with a 10K pullup to
        the +9v
        > > that I power my mics with and a 10K pull down to ground... The other
        > input
        > > to the opamp is grounded. (???) Yes with the resistor and
        > > inductor...)
        > >
        > > -----Original Message-----
        > > From: micbuilders@yahoogroups.com
        [mailto:micbuilders@yahoogroups.com]On
        > > Behalf Of dayVel
        > > Sent: Wednesday, September 28, 2005 12:32 PM
        > > To: micbuilders@yahoogroups.com
        > > Subject: [micbuilders] Re: SSM 2019/ INA217/INA163 circuit for
        > > AT853s
        > >
        > >
        > > Just use the circuits in the TI application notes. Make sure you use
        > > the suggested paralled resistor/inductor on the inputs.
        > >
        > >
        > > --- In micbuilders@yahoogroups.com, "Brian Dasilva"
        > > <bdasilva.rai@e...> wrote:
        > > > I need to build a small (well X2 9v batterys + circuit) The data
        > > sheet tells
        > > > most... Richard tells more... Any cookbook circuits out there?
        > >
        > >
        > >
        > >
        > >
        > >
        > > Yahoo! Groups Links
        >
        >
        >
        >
        >
        >
        > Yahoo! Groups Links




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