Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: isaac_teller on February 15, 2024, 07:07:50 am
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Hello. I'm building a clone of a Bogen CHB10A circuit which uses a voltage doubler. The input jack is isolated from the chassis and so is the ground buss. The only connection between the buss and the chassis is a .047 class x capacitor. Is this the correct way to implement a voltage doubler? If I connect the buss in the usual way(only input end grounded) the fuse blows immediately. Thank you
https://el34world.com/Forum/index.php?action=dlattach;topic=23649.0;attach=72757;image
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There should be no problem connect the ground buss to chassis. I suspect you have some other issue. Maybe a wiring error.
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So does this amp run a cutthroat doubler, straight off of the AC mains?
I'm thinking it must, otherwise your questions don't make much sense to me.
Btw, X-type caps are meant to go across an AC line pair. Y-type are used, sometimes in pairs, between one AC phase and ground.
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No. There is a power transformer(135 volt doubled to 270 giving about 380 unloaded). I've since solved the problem(the fuse was way too small for the amp). Got rid of the X-cap also.
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fuse was way too small for the amp
once you make your way to the all-steel fuse, the problems become self evident :icon_biggrin:
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fuse was way too small for the amp
once you make your way to the all-steel fuse, the problems become self evident :icon_biggrin:
I suggest going straight for the piece of copper tubing, though the "blown fuse wrapped in foil" deserves a mention.
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No. There is a power transformer(135 volt doubled to 270 giving about 380 unloaded). I've since solved the problem(the fuse was way too small for the amp). Got rid of the X-cap also.
Huh, really. In that case, I don't know what was stopping them from simply tying the negative side of the caps to chassis.
Fisher used an xfmr full-wave doubler supply in their Philharmonic consoles, and they were tied directly to chassis like any other PSU.