Friday, May 29, 2015

Blackstar HT100 Barbecue: Replacing The Tube Board.

I'd worked on this Blackstar HT100 head a while ago and it has served its owner well for the last few years. I'm not entirely sure how the story goes but it is said that a beer got spilled on/in it but who knows?

Either way it had a major cookout which lunched the tube board. Lucky for me it is a separate piece of hardware AND there was available a schematic for the tube board.

On the other hand, the tube board is made of unobtainium. My first thought had been to get a new tube board but that was out of the question.

Looking at the diagram it seemed that I could hand wire it ala Marshall and then I'd figure out how to connect it to the main board. So I installed four ceramic sockets and started in on the wiring and resistors and hookup wire.

When I got to connecting the tube board to the main board, removing the molex connectors was going to be problematic because they're glued to the board. I decided to make loops in the ends of the hookup wires, and lucky me, there was enough separation so that I wasn't going to have problems with bridging.

I finished the wiring today and it powered up the first time. So tonight I'll let it have a slow simmer and see how it goes.

1 comment:

  1. Hey Robert keep up the great work!

    I think it's great that you come from an attorney background and prove that your attention for detail, carries over to tube amp repair.

    I've been fixing tube amps for years and it's all about returning the amplifier to the perfect environment that it was designed to be in

    I just repaired a Fender "the Twin" that had a similar fire and I basically had to clean any trace of carbon burning (great conductor) and rebuild the board.
    It ends up a loose wire in the bias circuit shorted things out along with broken bias pots

    Most repair guys/gals wouldn't have touched this amp as it took 12 hours to fix everything along with new tubes
    That why we do what we do because of the tube passion!