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Ampeg SVT-CL Heritage fan wiring (AC-Board related)

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  • Ampeg SVT-CL Heritage fan wiring (AC-Board related)

    I have CL Heritage on my workbench right now, I'm rewiring it from 115V to 240V
    Nic to see that the boards are thicker and everything is just better done that the regular ones made far East. This is the first Heritage I work on right now.

    I've done that 2-3 times with the regular CL model but I have a problem here where I should connect the cooling fan?

    Every free pin there (with a high voltage) seems to be 230-240V and I've tested all the comibnations (original seating is J11+J14). The fan works at around 120V. So, is there any way to connect it to 120V or do I need to change the fan to european model?
    Am I missing something here?
    Attached Files

  • #2
    Originally posted by boroman View Post
    I have CL Heritage on my workbench right now, I'm rewiring it from 115V to 240V
    Nic to see that the boards are thicker and everything is just better done that the regular ones made far East. This is the first Heritage I work on right now.

    I've done that 2-3 times with the regular CL model but I have a problem here where I should connect the cooling fan?

    Every free pin there (with a high voltage) seems to be 230-240V and I've tested all the comibnations (original seating is J11+J14). The fan works at around 120V. So, is there any way to connect it to 120V or do I need to change the fan to european model?
    Am I missing something here?
    Could you post a schematic?
    I think you can leave the fan connected to the 120V PT primary tap.

    - Own Opinions Only -

    Comment


    • #3
      J14 & J15 are the fan supply and should be off the 120v tapping. Didn't know they were multi voltage primary windings.
      Support for Fender, Marshall, Mesa, VOX and many more. https://jonsnell.co.uk

      Comment


      • #4
        Originally posted by Helmholtz View Post

        Could you post a schematic?
        I think you can leave the fan connected to the 120V PT primary tap.
        The 120V Fan is wired across one of the two split primaries. it's shown in the Tech Note posted below. I've attached schematics on the SVT-CL. The Fan is connected to J15 & J16. J16 then connects to terminals J29 & J30, one of which will be one of the two primary windings. So, the Primaries of the Power xfmr becomes an Autoformer for the Fan.

        Tech Note -- Transformer connections drawing.pdf
        Tech Note -- 120V to 230V conversion.pdf
        AC Terminal PCB Schematics and Parts List (31904p1_).pdf
        Attached Files
        Last edited by nevetslab; 07-22-2020, 04:26 AM.
        Logic is an organized way of going wrong with confidence

        Comment


        • #5
          Originally posted by nevetslab View Post

          The 120V Fan is wired across one of the two split primaries. it's shown in the Tech Note posted below. I've attached schematics on the SVT-CL. The Fan is connected to J15 & J16. J16 then connects to terminals J29 & J30, one of which will be one of the two primary windings. So, the Primaries of the Power xfmr becomes an Autoformer for the Fan.

          Tech Note -- Transformer connections drawing.pdf
          Tech Note -- 120V to 230V conversion.pdf
          AC Terminal PCB Schematics and Parts List (31904p1_).pdf
          All of your links are invalid. Response is;
          Invalid Page URL. If this is an error and the page should exist, please contact the system administrator and tell them how you got this message.
          Support for Fender, Marshall, Mesa, VOX and many more. https://jonsnell.co.uk

          Comment


          • #6
            The links in hos text are broke, but the ones in the box right below that all work for me.
            Education is what you're left with after you have forgotten what you have learned.

            Comment


            • #7
              Originally posted by Enzo View Post
              The links in hos text are broke, but the ones in the box right below that all work for me.
              Odd. After I posted those links last night, they read ok, and there wasn't the boxed section below it. Prior to that, having loaded those from my computer's database, I kept getting error messages requesting URL, even though loaded via Upload Attachments. This isn't the first time I've had this problem with the new software.
              Logic is an organized way of going wrong with confidence

              Comment


              • #8
                COmpare the link addresses between the two sets in your post. The ones in teh text all have an extra bunch of numbers added on teh end.
                Education is what you're left with after you have forgotten what you have learned.

                Comment


                • #9
                  Originally posted by nevetslab View Post

                  Odd. After I posted those links last night, they read ok, and there wasn't the boxed section below it. Prior to that, having loaded those from my computer's database, I kept getting error messages requesting URL, even though loaded via Upload Attachments. This isn't the first time I've had this problem with the new software.
                  After you uploaded the attachments, did you ask that they be 'inserted' into the post?
                  "Everything is better with a tube. I have a customer with an all-tube pacemaker. His heartbeat is steady, reassuring and dependable, not like a modern heartbeat. And if it goes wrong he can fix it himself. You can't do that with SMD." - Mick Bailey

                  Comment


                  • #10
                    Originally posted by g1 View Post

                    After you uploaded the attachments, did you ask that they be 'inserted' into the post?
                    During the uploading procedure, the attachment lands in the 'list' below the post, with an Insert or Delete command. I selected Insert for each attachment, ending with the three insertions. When I previewed it, I saw the three attachments, and could select each and see them open. It wasn't until later that I saw the attachments that no longer work, then the 'list' in the box, which DO work. I was using my laptop at work, which is an XP machine, with Mozilla Firefox and Google as the search engine.
                    Logic is an organized way of going wrong with confidence

                    Comment


                    • #11
                      Originally posted by Enzo View Post
                      COmpare the link addresses between the two sets in your post. The ones in teh text all have an extra bunch of numbers added on teh end.
                      I'm afraid I don't know how to do that.
                      Logic is an organized way of going wrong with confidence

                      Comment


                      • #12
                        Originally posted by nevetslab View Post

                        During the uploading procedure, the attachment lands in the 'list' below the post, with an Insert or Delete command. I selected Insert for each attachment, ending with the three insertions. When I previewed it, I saw the three attachments, and could select each and see them open. It wasn't until later that I saw the attachments that no longer work, then the 'list' in the box, which DO work. I was using my laptop at work, which is an XP machine, with Mozilla Firefox and Google as the search engine.
                        Try not using the 'insert' command, just attach it. It will give the working 'box' list, without the added links in the text, which do not seem to work.
                        "Everything is better with a tube. I have a customer with an all-tube pacemaker. His heartbeat is steady, reassuring and dependable, not like a modern heartbeat. And if it goes wrong he can fix it himself. You can't do that with SMD." - Mick Bailey

                        Comment


                        • #13
                          Nevets, seeing the link:

                          I am no computer guy, so if I can do it you can too. When I mouse over a link, I can see it kinda highlights itself, inviting me to click, and somewhere on your screen - for me it is along the bottom edge - the link address will appear. Just a small line of print along the bottom edge.


                          This is kinda like on my email when I get one telling me they are Pay Pal and suspending my account. The address says paypal, but if I mouse over that address, it shows me who really sent it, and the address is nothing remotely like PayPal.

                          I could be wrong, but I bet if you went in and edited those extra numbers off those links, they'd probably start working.
                          Education is what you're left with after you have forgotten what you have learned.

                          Comment


                          • #14
                            Originally posted by nevetslab View Post
                            The 120V Fan is wired across one of the two split primaries. it's shown in the Tech Note posted below. I've attached schematics on the SVT-CL. The Fan is connected to J15 & J16. J16 then connects to terminals J29 & J30, one of which will be one of the two primary windings. So, the Primaries of the Power xfmr becomes an Autoformer for the Fan.

                            You're the man! Thanks Nevets.
                            You know, between J15 & J16 there is 0V when I tested it, but I've tested it without tubes so only in power_on mode. When I hit standby, VIOLA! of course,between J15&J16 is 120V then!

                            Do you think I should leave 3 jumpers for the polarity switch (-/0/+) or its obsolete in Europe anyway?

                            Comment


                            • #15
                              Leaving 3 jumpers for the polarity switch? I see in the schematic they have a UL rated 3.3nF cap, one side connected to chassis gnd, the other selecting either side of the AC Mains. I hadn't thought on that switch much, though just recently, on an SVT-CL I was working on, having juggled power tubes for a better balance since the last time I had worked on it, I was still getting more hum than I'm used to hearing (usually none audibly), but after flipping thru the two extremes on that switch, then coming back to mid-position, the hum went away. No explanation for that, but, it is safe to leave it connected, and just keep it in the mid-position, which is out of circuit.

                              Lets see if some of the other folks on your side of the ocean have to say on that.
                              Logic is an organized way of going wrong with confidence

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