Announcement

Collapse
No announcement yet.

Peavey 400 amp missing part.

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

  • #46
    Originally posted by Enzo View Post
    I didn't expect it to be thermalling. But if that diode circuit opens - as it would if the connector was intermittant - then the outputs would slam on full. THAT is why it matters.
    Is the "heat diode" the 13886 CR14?
    When the going gets weird... The weird turn pro!

    Comment


    • #47
      Yes.


      If that diode or its circuit go open, then Q2 and Q12 are turned full on.
      Education is what you're left with after you have forgotten what you have learned.

      Comment


      • #48
        Originally posted by Enzo View Post
        Yes.


        If that diode or its circuit go open, then Q2 and Q12 are turned full on.
        Not to derail the thread but I just ordered that exact part for that Peavey PA that I working on. I guess I got confused when Enzo asked "Is the connector for the heat diode loose?". The 13886 on my module just has a heat tubing around the longer side of the leg of the 13886. I know that there is a clamp on heat detection for the AC power in that mounts on top of one the transistors or in some cases mounts just to the heat sink alone. I was just curious if there is a mounting for the 13886 on this particular model.
        Click image for larger version

Name:	13886-1sm.JPG
Views:	1
Size:	2.01 MB
ID:	853656
        Click image for larger version

Name:	13886-2sm.JPG
Views:	1
Size:	1.61 MB
ID:	853655
        When the going gets weird... The weird turn pro!

        Comment


        • #49
          The diode itself is clamped to the heat sink, and a two wire cable ending in a Molex plugs onto the main power amp board.
          Education is what you're left with after you have forgotten what you have learned.

          Comment


          • #50
            Oh okay I think I remember seeing that version on an old Peavey bass amp.
            When the going gets weird... The weird turn pro!

            Comment


            • #51
              Look at the 400BH file instead of the 400B/G. The BH includes the layout for the power transistors, and the diode in right next to its connector between Q4 and Q5. There is a two wire Molex nearby leading over to the main board.

              The 400BH and 400B/G are almost identical, but the layout includes all the boards.
              Education is what you're left with after you have forgotten what you have learned.

              Comment


              • #52
                When I ordered parts for the Peavey I said to myself "don't forget to test that somewhat hidden diode". Of course total brain fart and had to order it separately. I even remember reading the Peavey cross reference guide about the 13886 diode. They recommend their direct batch of dual diodes since they have very specific design requirements for that diode. There is a thread here talking about just putting a 1N4001 or something in there but best to get the part from Peavey.
                When the going gets weird... The weird turn pro!

                Comment


                • #53
                  If you put a single diode in its place, the amp will work, but you will get more crossover distortion than with the dual diode.
                  Education is what you're left with after you have forgotten what you have learned.

                  Comment

                  Working...
                  X