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Re: [cosmacelf] LM3900 replacement for CA3140 op-amp?

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  • Dana Myers
    ... Exactly. Scott emailed and followed-up that it s a CA3401. Direct swap for LM3900. Though I rather doubt the CA3401 is dead. Cheers - Dana K6JQ
    Message 1 of 21 , Jul 8 1:49 PM
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      On 7/8/2013 1:36 PM, David W. Schultz wrote:
       


      I think that you meant the bipolar CA3401 quad opamp which is quite a
      different beast from the biMOS LM3140 single opamp.

      Yes, the LM3900 will be just fine.


      Exactly. Scott emailed and followed-up that it's a CA3401.
      Direct swap for LM3900. Though I rather doubt the CA3401
      is dead.

      Cheers -
      Dana  K6JQ
    • somaspack
      Thanks for the help everyone! I too wonder if the CA3401 is dead. My test was to try to tape-out: there is a signal from Q to the input but there is no output
      Message 2 of 21 , Jul 9 10:00 AM
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        Thanks for the help everyone!

        I too wonder if the CA3401 is dead. My test was to try to tape-out: there is a signal from Q to the input but there is no output coming from the output of the op-amp. I also tried tape-in, and while there is a variable voltage on the input, there is no output from the op-amp. It's a pretty simple circuit with only a few resistors and ceramic caps which I cannot see failing.

        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?

        Scott

        --- In cosmacelf@yahoogroups.com, Dana Myers <dana.myers@...> wrote:
        >
        > On 7/8/2013 1:36 PM, David W. Schultz wrote:
        > >
        > >
        > > I think that you meant the bipolar CA3401 quad opamp which is quite a
        > > different beast from the biMOS LM3140 single opamp.
        > >
        > > Yes, the LM3900 will be just fine.
        > >
        >
        > Exactly. Scott emailed and followed-up that it's a CA3401.
        > Direct swap for LM3900. Though I rather doubt the CA3401
        > is dead.
        >
        > Cheers -
        > Dana K6JQ
        >
      • Dana Myers
        ... I *have* seen a resistor fail once - a 1ohm, 1/2W film resistor in the collector supply of a 1W VHF amplifier. But it s rare. I can imagine a capacitor
        Message 3 of 21 , Jul 9 10:23 AM
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          On 7/9/2013 10:00 AM, somaspack wrote:
           

          Thanks for the help everyone!

          I too wonder if the CA3401 is dead. My test was to try to tape-out: there is a signal from Q to the input but there is no output coming from the output of the op-amp. I also tried tape-in, and while there is a variable voltage on the input, there is no output from the op-amp. It's a pretty simple circuit with only a few resistors and ceramic caps which I cannot see failing.

          I *have* seen a resistor fail once - a 1ohm, 1/2W film resistor in the collector supply
          of a 1W VHF amplifier. But it's rare. I can imagine a capacitor failing, too, but they're all
          ceramics?

          I'd suggest probing the circuit for DC voltage levels first to make sure the bias
          levels are right.

          Do you have a link to the circuit?

          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?

          I would expect this does not make a difference.

          Cheers -
          Dana  K6JQ

        • somaspack
          Yes, thanks! Scott
          Message 4 of 21 , Jul 9 11:02 AM
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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 5 of 21 , Jul 10 12:56 PM
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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 6 of 21 , Jul 10 1:04 PM
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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 7 of 21 , Jul 10 1:17 PM
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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 8 of 21 , Jul 10 1:23 PM
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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 9 of 21 , Jul 10 1:30 PM
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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 10 of 21 , Jul 11 3:49 AM
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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 11 of 21 , Jul 11 3:53 AM
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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 12 of 21 , Jul 11 6:57 AM
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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 13 of 21 , Jul 11 12:34 PM
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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 14 of 21 , Jul 12 2:15 AM
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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 15 of 21 , Jul 22 9:21 PM
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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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