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Hammond BCV main Fuse value

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  • Hammond BCV main Fuse value

    I'm replacing the main power wiring and i was going to add a fuse on the hot . Is 5 amp SB ok or should i go a little higher. I saw that 4 amp is used in a B3 but i figured that with the second generator i should go with a higher value.

  • #2
    I was reading another thread and Geoelectro said "Putting a single fuse on the whole organ is not a good idea. You have motors and the speaker cabinet all running on that one fuse" so i will not put a fuse. Now the next question is do i connect the power ground wire to the chassis ground ?
    Also there is a big capacitor connected between the B+ terminal on the preamp and ground is it necessary ? it looks like an add on


    • #3
      The point I was addressing was using a "total organ" fuse offers much less protection to the preamp, which is typically where fuse protection is needed. A total organ fuse has to be a much higher value which makes it less likely to detect and react to the smaller current changes in the preamp. However, the preamp fuse is usually more applicable for organs that have rectifier tubes in their preamps which the BCV doesn't.

      Hammonds didn't come with a power ground so you must be adding one? There is a leakage test you should do before attempting this add-on. The info is in the front section of most every Hammond service manual.

      That cap was likely added in an attempt to lower hum. You can leave it there or remove it and see if hum increases or even measure the AC component at that B+ point to see if it's unusually high.



      • #4
        Thanks Geo