Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Stankfut on June 23, 2014, 12:22:37 pm
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Is it possible to use a jack to switch circuits in an amp? Specifically, I want to modify one of my SE amps with a Herzog output. I want the Herzog jack to disconnect the internal speaker when I plug it in. I feel that I'm missing something......
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The input jack on probably every guitar amp you've ever played incorporates a switch.
The schematic in this thread (http://el34world.com/Forum/index.php?topic=17235.msg172427#msg172427) shows a switched output jack. The rectangle at the speaker jack is the sleeve (ground) connection. The black arrow, which connects to the 10Ω 5w resistor is the switched contact. The other part which looks like the tip (hot) contact of a Switchcraft jack is the tip connection.
You would use a Switchcraft 12A jack (or the equivalent Cliff jack), like those sold by Hoffman.
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He needs switching which *connects* a dummy-load when not using a speaker.
So he has to use a *second* jack for his herzog output to another amp.
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He needs switching which *connects* a dummy-load when not using a speaker.
So he has to use a *second* jack for his herzog output to another amp.
Duh! Thanks!
How about the same ol' Switchcraft 12A jack... OT secondary wires go to the Herzog Jack, with the ground lug of the Herzog Jack connected to the ground lug of the Speaker Jack. Switched contact of the Herzog Jack connects to the hot lug of the Speaker Jack.
With no plug in the Herzog Jack, signal normals from hot to switched lug, then over to Speaker Jack hot, with Speaker Jack disconnected when a plug is in the Herzog Jack.
Someone like Sluckey can draw up a quick diagram; it might be a little while before I'll have a chance to draw it myself.
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Switchcraft 13A
I'm thinkin' this would do the trick. Just unplug the speaker and use your herzog/line out jack, or use the line out with the speaker connected also.
Hope this helps.
Peace,
Aaron
Edit: I reviewed the schematic today, and the 13A is not necessary. I must have really wanted to use that jack when I drew up the schematic. :w2:
I've fixed the schematic so that it's using a regular style 12A input switching jack. Sorry if this caused any sort of confusion. I had just got done wiring an OT speaker out to switch impedance using the 13A just a few days before I drew up the schematic. Please excuse my mistake.