Groups > sci.electronics.design > #460493

Re: Using consumer-grade power amp as Power opamp

Newsgroups	sci.electronics.design
Date	2017-05-16 06:06 -0700
References	<J8SdnQ82rpuXXYTEnZ2dnUU7-KvNnZ2d@giganews.com> <85b69e91-8739-4d25-929b-714dfefc79cb@googlegroups.com> <0MBSA.49093$R12.33403@fx16.am4>
Message-ID	<34782895-8b35-416e-a686-792fd9fed4cc@googlegroups.com> (permalink)
Subject	Re: Using consumer-grade power amp as Power opamp
From	Phil Allison <pallison49@gmail.com>

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Chris Jones wrote:

------------------

> 
> >> Has anyone used any of the consumer-grade audio power amps such as the
> >> LM1825, TDA2030, or TDS7297  as a basic DC power opamp?
> >>
> >
> >
> > ** Generally they are not unity gain stable.
> >
> >  Audio power amps have a voltage gain of 10 to 50 times in most cases.
> >
> 
> Yes, that is a consideration. The "noise gain" needs to be high but not 
> necessarily the gain from the input of the circuit as a whole. You can 
> of course lower the gain back to unity by attenuating the input, or a 
> number of other tricks.
> 

** A low impedance between the + and - inputs does the trick. 

   Say 100hms plus a 22nF cap in series. 

   Leaves the DC condiitons in place. 


....  Phil

Thread

Using consumer-grade power amp as Power opamp "Dave M" <dgminala@mediacombb.net> - 2017-05-15 09:49 -0500
  Re: Using consumer-grade power amp as Power opamp Don Y <blockedofcourse@foo.invalid> - 2017-05-15 08:09 -0700
    Re: Using consumer-grade power amp as Power opamp "Dave M" <dgminala@mediacombb.net> - 2017-05-16 12:53 -0500
      Re: Using consumer-grade power amp as Power opamp tabbypurr@gmail.com - 2017-05-17 03:04 -0700
      Re: Using consumer-grade power amp as Power opamp mrdarrett@gmail.com - 2017-05-18 09:02 -0700
  Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-15 08:18 -0700
    Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-15 17:15 -0700
      Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-16 05:49 -0700
        Re: Using consumer-grade power amp as Power opamp "Dave M" <dgminala@mediacombb.net> - 2017-05-16 13:00 -0500
  Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-15 15:57 +0000
  Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highlandtechnology.com> - 2017-05-15 09:02 -0700
  Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-15 09:03 -0700
    Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-15 16:07 +0000
      Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highlandtechnology.com> - 2017-05-15 09:17 -0700
        Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-15 16:46 +0000
          Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-15 10:08 -0700
            Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-15 11:13 -0700
            Re: Using consumer-grade power amp as Power opamp Clifford Heath <clifford.heath@gmail.com> - 2017-05-16 10:14 +1000
              Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-16 08:36 +0000
  Re: Using consumer-grade power amp as Power opamp Tim Wescott <seemywebsite@myfooter.really> - 2017-05-15 12:48 -0500
    Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-15 11:18 -0700
      Re: Using consumer-grade power amp as Power opamp Tim Wescott <tim@seemywebsite.really> - 2017-05-16 10:08 -0500
        Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-16 11:19 -0700
          Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-16 11:32 -0700
            Re: Using consumer-grade power amp as Power opamp Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-05-16 16:02 -0400
              Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highlandtechnology.com> - 2017-05-16 20:19 -0700
  Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-15 16:59 -0700
    Re: Using consumer-grade power amp as Power opamp Chris Jones <lugnut808@spam.yahoo.com> - 2017-05-16 21:54 +1000
      Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-16 06:06 -0700
      Re: Using consumer-grade power amp as Power opamp tabbypurr@gmail.com - 2017-05-16 06:57 -0700
  Re: Using consumer-grade power amp as Power opamp Winfield Hill <hill@rowland.harvard.edu> - 2017-05-15 18:42 -0700
    Re: Using consumer-grade power amp as Power opamp krw@notreal.com - 2017-05-15 21:55 -0400
      Re: Using consumer-grade power amp as Power opamp Winfield Hill <hill@rowland.harvard.edu> - 2017-05-16 05:53 -0700
        Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-16 14:23 +0000
        Re: Using consumer-grade power amp as Power opamp krw@notreal.com - 2017-05-16 12:28 -0400
    Re: Using consumer-grade power amp as Power opamp "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> - 2017-05-16 20:27 +0100
      Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-16 16:03 -0700
        Re: Using consumer-grade power amp as Power opamp "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> - 2017-05-17 19:34 +0100
          Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-17 11:47 -0700
          Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-18 04:43 -0700
        Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-18 16:30 +0000
      Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-16 16:07 -0700
  Re: Using consumer-grade power amp as Power opamp jurb6006@gmail.com - 2017-05-16 00:45 -0700
  Re: Using consumer-grade power amp as Power opamp sroberts6328@gmail.com - 2017-05-18 08:57 -0700
    Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-19 06:29 -0700

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