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    Need help on wiring in a Mk4 Curcio cap board(pictures hopefully)

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    Pooch

    Posts : 53
    Join date : 2009-12-01
    Age : 66
    Location : Wa

    Need help on wiring in a Mk4 Curcio cap board(pictures hopefully)

    Post by Pooch on Wed Mar 09, 2011 5:11 pm

    Could someone tell me the optimal way of wiring this board to a VTA driver board. If I eliminate the bia hookup, do I just ignore tat section on the cap board or can I incorporate that in another section on the board. Thanks. I'll try and import a couple of pictures.



    tubes4hifi
    Admin

    Posts : 1292
    Join date : 2008-11-30

    Re: Need help on wiring in a Mk4 Curcio cap board(pictures hopefully)

    Post by tubes4hifi on Fri Mar 11, 2011 8:38 pm

    there is no bias connection on that board.
    Pin 1 of PCB to pin 8 of rectifier tube and input of choke.
    Tie Pin 2 & 3 together and connect to output of choke and to both OPTs B+
    Pin 4 goes to VTA driver PCB B+
    Ground goes to VTA GND and chassis ground.

    Pooch

    Posts : 53
    Join date : 2009-12-01
    Age : 66
    Location : Wa

    Re: Need help on wiring in a Mk4 Curcio cap board(pictures hopefully)

    Post by Pooch on Sat Mar 12, 2011 6:23 pm

    Thanks Roy. Here's the directions I received, after a request. Something didn't add up in my mind or I was simply missing the point somewhere. I asked for clarification, but didn't get a reply. These directions to me indicate hooking the choke to terminal 2 and 3. Seemed to me it should be tied into terminal 1 first and then to terminal 2, but I just wasn't sure.Relative rookie here, but I'm gaining (I think) Very Happy

    It will work with your VTA board - here are the comparable connections:


    CAE PC-M4U Terminal # Point on VTA Schematic
    1 Pin 8 of 5AR4


    2 Junction of Choke & 6.8K resistor


    3 Junction of Choke & 6.8K resistor


    4 B+ 400 line (junction of R13 & R15)




    On the CAE-M4U board, the terminals can be identified as follows:
    Terminal #1 - near top of R1
    Terminal # 2 - near bottom of R9
    Terminal #3 - near top of R9
    Terminal #4 - between C5 & C8
    Ground Terminal - between C2 & C4 (near top of R6 and bottom of R5)




    You will have to remove one of the two 6.8K resistors as there are now two - one is on our board (R9) and the other is located somewhere in your amp electrically between the choke and the B+ 400 line. You can remover either one.





    tubes4hifi
    Admin

    Posts : 1292
    Join date : 2008-11-30

    Re: Need help on wiring in a Mk4 Curcio cap board(pictures hopefully)

    Post by tubes4hifi on Sat Mar 12, 2011 7:19 pm

    the choke goes between 1 and 2, so my same directions as last reply. You can remove the existing 6.8K resistor connected to the existing quad cap (and remove the quad cap!) and then wire in the Curcio quad with it's own 6.8K, pretty simple
    there is no bias connection on that board.
    Pin 1 of PCB to pin 8 of rectifier tube and input of choke.
    Tie Pin 2 & 3 together and connect to output of choke and to both OPTs B+
    Pin 4 goes to VTA driver PCB B+
    Ground goes to VTA GND and chassis ground

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    Re: Need help on wiring in a Mk4 Curcio cap board(pictures hopefully)

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