Announcement

Collapse
No announcement yet.

Vibrolux 5f11 build from integrated amp

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Vibrolux 5f11 build from integrated amp

    Hey folks - novice here with my first build. I had done some reading on converting old integrated tube amps into guitar amps when the tube complement and transformers made sense for a conversion. Found this 1959 Craftsman "Conterto" CA-11 amp on eBay a while back for $70 and grabbed it for the tube complement which I thought might match some of the old Fender circuits. Did some research and was originally going to build a Tweed Deluxe 5e3, but then figured the tube complement exactly matched a Vibrolux 5F11, so I'm going with that.

    Original front panel


    Front panel parts installed:


    Original shot from rear


    Guts of integrated amp before stripping out


    Project with new sockets installed and filiment runs in place


    Shot from side showing power and output transformers
    tonebrulee

  • #2
    Also, part of the challenge here is there's no room for a proper layout on a card or turret board, so I have to re-interpret the layout diagram and "fly" the components old school! I did wire up the power supply on a couple of terminal strips though. I'm trying to route all the connections properly to reduce hum and will be using a multi-star grounding scheme. A friend suggested covering the component leads with housing stripped from other wire which seems like a cool idea, so I've been doing that.

    If anybody sees any problems or has any suggestions I'd be happy to hear from ya. Thanks.




    Layout diagram showing completed wiring in orange:

    tonebrulee

    Comment


    • #3
      Need help re: review of my planned star-grounding scheme

      I've been studying up on grounding (i.e. "the other half of the circuit") and have come up with the star grounding scheme shown below. There are 18 ground points in the schematic and the different colors each represent a local star node. There are 5 nodes (blue, orange, brown, purple, yellow) and each will have a wire run to the star. Plus 4 individual ground points (9, 14, 16, 17 in green) which will each be connected directly to the star.



      Any feedback (no pun intended!) very much appreciated.
      tonebrulee

      Comment


      • #4
        Further to my comments on the telecaster forum, read Merlin's article on grounding here:

        Click here to view the article (360kb PDF)
        Building a better world (one tube amp at a time)

        "I have never had to invoke a formula to fight oscillation in a guitar amp."- Enzo

        Comment


        • #5
          Merlin's article will take a while to digest. The first thing you will need is an updated schematic. Old Fender schematics do not meet current safety standards. First of all, eliminate the "Death Cap" at point 9. Add a three wire line cord or IEC socket for power cord connection. One side of the heater winding is grounded, that system is (almost) never used these days. You will want to use a heater winding with a center tap, or create a "virtual center tap" with a pair of 100 ohm 1/2W resistors. Lastly, show the ground connections of the input, speaker and footswitch jacks. These will need to be isolated from that chassis, either with stepped washers or plastic jacks.
          WARNING! Musical Instrument amplifiers contain lethal voltages and can retain them even when unplugged. Refer service to qualified personnel.
          REMEMBER: Everybody knows that smokin' ain't allowed in school !

          Comment


          • #6
            Originally posted by loudthud View Post
            Merlin's article will take a while to digest. The first thing you will need is an updated schematic. Old Fender schematics do not meet current safety standards. First of all, eliminate the "Death Cap" at point 9. Add a three wire line cord or IEC socket for power cord connection. One side of the heater winding is grounded, that system is (almost) never used these days. You will want to use a heater winding with a center tap, or create a "virtual center tap" with a pair of 100 ohm 1/2W resistors. Lastly, show the ground connections of the input, speaker and footswitch jacks. These will need to be isolated from that chassis, either with stepped washers or plastic jacks.
            Yup, Merlin is one of the first things I read... been digesting it for months. Been using the old schematic for illustration only - have been planning all the updated mods you recommended. Thanks.
            tonebrulee

            Comment


            • #7
              Any new updates? Looking good so far.
              My Builds:
              5E3 Deluxe Build
              5F1 Champ Build
              6G15 Reverb Unit Build

              Comment


              • #8
                Originally posted by Wittgenstein View Post
                Any new updates? Looking good so far.
                Hey, thanks. Guess I'm a low-down, no-good two-timing scoundrel b/c I have the same post going over at TDPRI (link below) where I've had some luck gathering info in response to my grounding post above. 'Bout ready to move ahead with building though and will be posting build updates to the thread here too.

                Vibrolux 5f11 build from integrated amp - TDPRI
                tonebrulee

                Comment

                Working...
                X