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Re: LM3900 replacement for CA3140 op-amp?

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  • somaspack
    Yes, thanks! Scott
    Message 1 of 21 , Jul 9, 2013
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      Yes, thanks!

      Scott

      >
      > Do you have a link to the circuit?
      >
    • jdripper
      ... I ve mostly only seen resistors fail when they are operated over their rated power dissipation, or under it but over temperature. They usually fail open.
      Message 2 of 21 , Jul 10, 2013
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        --- In cosmacelf@yahoogroups.com, "somaspack" <somaspack@...> wrote:
        > It's a pretty simple circuit with only a few resistors and ceramic caps which I cannot see
        > failing.

        I've mostly only seen resistors fail when they are operated over their rated power dissipation, or under it but over temperature. They usually fail open.

        I was astounded to find a resistor in a PDP-11/05 front panel that failed shorted, so apparently that can happen also, but I think it's very unlikely.

        > BUT here is another question. I am not using a cassette recorder, I am using
        > a PC with mic/headphone I/O. Does this make a difference?

        If you're actually using a microphone input, rather than line input, then you will probably need an attenuator, as the level will almost certainly be far too high.

        For a line input, you just need to make sure that the level (and gain control in the PC's mixer settings) isn't so high as to cause clipping.

        Eric
        N2ES
      • /M
        Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin. Magnus
        Message 3 of 21 , Jul 10, 2013
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          Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
           
          Magnus
        • Dana Myers
          ... The original poster corrected himself - it s a CA3401, which was the RCA second-source for the LM3900. It s a quad Norton amp. Also, sound card input on
          Message 4 of 21 , Jul 10, 2013
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            On 7/10/2013 1:04 PM, /M wrote:
             

            Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
             


            The original poster corrected himself - it's a CA3401, which was the RCA second-source for
            the LM3900. It's a quad Norton amp.

            Also, sound card input on most PCs both a mic level and line-level input, the original
            poster would notice pretty quickly if over-driving the mic input :-)

            Cheers -
            Dana  K6JQ

          • joshbensadon
            ... Wow, I never heard of a resistor failing in a short condition. I m guessing that must be a very rare occurrence. I once found a diode marked backwards! It
            Message 5 of 21 , Jul 10, 2013
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              > I've mostly only seen resistors fail when they are operated over their rated power dissipation, or under it but over temperature. They usually fail open.
              >
              > I was astounded to find a resistor in a PDP-11/05 front panel that failed shorted, so apparently that can happen also, but I think it's very unlikely.



              Wow, I never heard of a resistor failing in a short condition.
              I'm guessing that must be a very rare occurrence.

              I once found a diode marked backwards! It was a 1N914 diode. I found it in a new circuit board off the assembly line that wasn't working. I kept it for a long time on my bench and showed a few people, then decided to throw it away.

              My mistake for not buying a lottery ticket that day.

              :)J
            • /M
              Ooops! Missed that. I happen to have the Applican Note ICAN-6934 Cassete Tape I/O For COSMAC Microprocessor Systems . Maybe I should run the leaflet in the
              Message 6 of 21 , Jul 10, 2013
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                Ooops! Missed that.
                 
                I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC Microprocessor Systems'.
                Maybe I should run the leaflet in the scanner and share it?!
                 
                Magnus
                 
                 
                ----- Original Message -----
                Sent: Wednesday, July 10, 2013 10:17 PM
                Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                 

                On 7/10/2013 1:04 PM, /M wrote:
                 

                Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
                 


                The original poster corrected himself - it's a CA3401, which was the RCA second-source for
                the LM3900. It's a quad Norton amp.

                Also, sound card input on most PCs both a mic level and line-level input, the original
                poster would notice pretty quickly if over-driving the mic input :-)

                Cheers -
                Dana  K6JQ

              • Jorgen Nordqvist
                Would love a copy of that application note, if you have the time. _____ From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of /M
                Message 7 of 21 , Jul 11, 2013
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                  Would love a copy of that application note, if you have the time.
                   

                  From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of /M
                  Sent: Thursday, 11 July 2013 6:31 AM
                  To: cosmacelf@yahoogroups.com
                  Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                   

                  Ooops! Missed that.
                   
                  I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC Microprocessor Systems'.
                  Maybe I should run the leaflet in the scanner and share it?!
                   
                  Magnus
                   
                   
                  ----- Original Message -----
                  Sent: Wednesday, July 10, 2013 10:17 PM
                  Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                   

                  On 7/10/2013 1:04 PM, /M wrote:
                   

                  Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
                   


                  The original poster corrected himself - it's a CA3401, which was the RCA second-source for
                  the LM3900. It's a quad Norton amp.

                  Also, sound card input on most PCs both a mic level and line-level input, the original
                  poster would notice pretty quickly if over-driving the mic input :-)

                  Cheers -
                  Dana  K6JQ

                  No virus found in this message.
                  Checked by AVG - www.avg.com
                  Version: 2013.0.3349 / Virus Database: 3204/6478 - Release Date: 07/09/13

                • /M
                  Later this evening. Magnus ... From: Jorgen Nordqvist To: cosmacelf@yahoogroups.com Sent: Thursday, July 11, 2013 12:49 PM Subject: RE: [cosmacelf] Re: LM3900
                  Message 8 of 21 , Jul 11, 2013
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                    Later this evening.
                     
                    Magnus
                     
                     
                    ----- Original Message -----
                    Sent: Thursday, July 11, 2013 12:49 PM
                    Subject: RE: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                     

                    Would love a copy of that application note, if you have the time.
                     

                    From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of /M
                    Sent: Thursday, 11 July 2013 6:31 AM
                    To: cosmacelf@yahoogroups.com
                    Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                     

                    Ooops! Missed that.
                     
                    I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC Microprocessor Systems'.
                    Maybe I should run the leaflet in the scanner and share it?!
                     
                    Magnus
                     
                     
                    ----- Original Message -----
                    Sent: Wednesday, July 10, 2013 10:17 PM
                    Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                     

                    On 7/10/2013 1:04 PM, /M wrote:
                     

                    Maybe there has already been this info, but as I recall, the CA3140 was a FET or even a MOSFET OPamp with almost infinite Zin.
                     


                    The original poster corrected himself - it's a CA3401, which was the RCA second-source for
                    the LM3900. It's a quad Norton amp.

                    Also, sound card input on most PCs both a mic level and line-level input, the original
                    poster would notice pretty quickly if over-driving the mic input :-)

                    Cheers -
                    Dana  K6JQ

                    No virus found in this message.
                    Checked by AVG - www.avg.com
                    Version: 2013.0.3349 / Virus Database: 3204/6478 - Release Date: 07/09/13

                  • ekeefe8051
                    Hello, A copy of the ICAN-6934 Application note is in the files section of this group in the VIP section. It is the first link. I hope this helps. ED
                    Message 9 of 21 , Jul 11, 2013
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                      Hello,

                      A copy of the ICAN-6934 Application note is in the files section of this group in the "VIP" section. It is the first link.

                      I hope this helps.

                      ED

                      --- In cosmacelf@yahoogroups.com, "Jorgen Nordqvist" <jnord@...> wrote:
                      >
                      > Would love a copy of that application note, if you have the time.
                      >
                      > _____
                      >
                      > From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf
                      > Of /M
                      > Sent: Thursday, 11 July 2013 6:31 AM
                      > To: cosmacelf@yahoogroups.com
                      > Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?
                      >
                      >
                      >
                      >
                      >
                      > Ooops! Missed that.
                      >
                      > I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For COSMAC
                      > Microprocessor Systems'.
                      > Maybe I should run the leaflet in the scanner and share it?!
                      >
                      > Magnus
                      >
                      >
                      >
                      > ----- Original Message -----
                      > From: Dana Myers <mailto:dana.myers@...>
                      > To: cosmacelf@yahoogroups.com
                      > Cc: /M <mailto:tubes@...> ; spacewar@...
                      > Sent: Wednesday, July 10, 2013 10:17 PM
                      > Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?
                      >
                      >
                      >
                      >
                      >
                      > On 7/10/2013 1:04 PM, /M wrote:
                      >
                      >
                      >
                      >
                      >
                      >
                      > Maybe there has already been this info, but as I recall, the CA3140 was a
                      > FET or even a MOSFET OPamp with almost infinite Zin.
                      >
                      >
                      >
                      >
                      > The original poster corrected himself - it's a CA3401, which was the RCA
                      > second-source for
                      > the LM3900. It's a quad Norton amp.
                      >
                      > Also, sound card input on most PCs both a mic level and line-level input,
                      > the original
                      > poster would notice pretty quickly if over-driving the mic input :-)
                      >
                      > Cheers -
                      > Dana K6JQ
                      >
                      >
                      >
                      >
                      >
                      >
                      > No virus found in this message.
                      > Checked by AVG - www.avg.com
                      > Version: 2013.0.3349 / Virus Database: 3204/6478 - Release Date: 07/09/13
                      >
                    • somaspack
                      Yep haven t got that far because there is no signal... and haven t had time to trace with Dana s excellent circuit analysis. Scott
                      Message 10 of 21 , Jul 11, 2013
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                        Yep haven't got that far because there is no signal... and haven't had time to trace with Dana's excellent circuit analysis.

                        Scott


                        --- In cosmacelf@yahoogroups.com, Dana Myers <dana.myers@...> wrote:
                        > Also, sound card input on most PCs both a mic level and line-level
                        > input, the original
                        > poster would notice pretty quickly if over-driving the mic input :-)
                        >
                        > Cheers -
                        > Dana K6JQ
                        >
                      • Jorgen Nordqvist
                        Found it, thanks Ed. _____ From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of ekeefe8051 Sent: Thursday, 11 July 2013 11:57 PM To:
                        Message 11 of 21 , Jul 12, 2013
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                          Found it, thanks Ed.


                          From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf Of ekeefe8051
                          Sent: Thursday, 11 July 2013 11:57 PM
                          To: cosmacelf@yahoogroups.com
                          Subject: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?

                           

                          Hello,

                          A copy of the ICAN-6934 Application note is in the files section of this group in the "VIP" section. It is the first link.

                          I hope this helps.

                          ED

                          --- In cosmacelf@yahoogroups.com, "Jorgen Nordqvist" <jnord@...> wrote:

                          >
                          > Would love a copy of that
                          application note, if you have the time.
                          >
                          > _____
                          >
                          >
                          From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf
                          > Of /M
                          > Sent: Thursday, 11 July 2013 6:31 AM
                          > To:
                          href="mailto:cosmacelf%40yahoogroups.com">cosmacelf@yahoogroups.com
                          >
                          Subject: Re: [cosmacelf] Re: LM3900 replacement for CA3140 op-amp?
                          >
                          >
                          >
                          >
                          >
                          > Ooops! Missed that.
                          >
                          > I happen to have the Applican Note ICAN-6934 'Cassete Tape I/O For
                          COSMAC
                          > Microprocessor Systems'.
                          > Maybe I should run the leaflet
                          in the scanner and share it?!
                          >
                          > Magnus
                          >
                          >
                          >
                          > ----- Original Message -----
                          > From: Dana Myers
                          <mailto:dana.myers@...>
                          > To:
                          href="mailto:cosmacelf%40yahoogroups.com">cosmacelf@yahoogroups.com
                          >
                          Cc: /M <mailto:tubes@...> ; spacewar@...
                          > Sent: Wednesday, July
                          10, 2013 10:17 PM
                          > Subject: Re: [cosmacelf] Re: LM3900 replacement for
                          CA3140 op-amp?
                          >
                          >
                          >
                          >
                          >
                          > On 7/10/2013
                          1:04 PM, /M wrote:
                          >
                          >
                          >
                          >
                          >
                          >
                          >
                          Maybe there has already been this info, but as I recall, the CA3140 was a
                          > FET or even a MOSFET OPamp with almost infinite Zin.
                          >
                          >
                          >
                          >
                          > The original poster corrected himself - it's a
                          CA3401, which was the RCA
                          > second-source for
                          > the LM3900. It's a
                          quad Norton amp.
                          >
                          > Also, sound card input on most PCs both a mic
                          level and line-level input,
                          > the original
                          > poster would notice
                          pretty quickly if over-driving the mic input :-)
                          >
                          > Cheers
                          -
                          > Dana K6JQ
                          >
                          >
                          >
                          >
                          >
                          >
                          > No virus found in this message.
                          > Checked by AVG -
                          www.avg.com
                          > Version: 2013.0.3349 / Virus Database: 3204/6478 - Release
                          Date: 07/09/13
                          >

                          No virus found in this message.
                          Checked by AVG - www.avg.com
                          Version: 2013.0.3349 / Virus Database: 3204/6481 - Release Date: 07/10/13

                        • somaspack
                          It was the CA3401 that was bad. There was also a little bit of trouble with the VIP mono in/out cables correctly jiggling the computer hardware to think there
                          Message 12 of 21 , Jul 22, 2013
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                            It was the CA3401 that was bad.

                            There was also a little bit of trouble with the VIP mono in/out cables correctly jiggling the computer hardware to think there was an input. A stereo 1/8" adapter fixed that.

                            Recording to the computer and the VIP reading back works the same as a cassette recorder. I am using WAV format.

                            Scott

                            > Hi All,
                            >
                            > I spent a few nights working on my old VIP getting it running again.
                            >
                            > One problem persists. I tried to use the tape I/O but that is not operable in sending or >receiving. So it looks like the CA3140 quad op-amp needs to be replaced. These are rather >rare and expensive. This IC is pin compatible with the LM3900, but would it be a drop-in >replacement for this circuit? Thanks.
                            >
                            > Scott
                            >
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