Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: waldner on April 15, 2022, 12:26:53 am
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I have attached two diagrams. The yellow one is said to be a way to wire a 2x12 cab so you can choose to run two separate amps in stereo (one to each speaker) or connect one amp to either input jack and run the speakers in parallel without the need for a switch. I initially found this yellow drawing confusing, so I drew my own in a way that makes more sense to me. Can anyone tell me if 1. the yellow one works and 2. if mine also works? Both use Switchcraft 14b jacks.
I think I understand why the yellow one works but adds unnecessary complexity of using the 5th connection of each jack when it's not needed. The 14b are switched stereo type jacks and the plugs going into them are mono so the ring and sleeve are the same and tied together. Am I wrong?
Now for the second part of the puzzle: Assuming both of these diagrams work as intended, I'd like to figure out a way to do the same thing but have the mono version being in series instead. This would raise the mono impedance to 16 ohms, assuming two 8 ohm speakers rather than cut it in half to 4 ohms. Possible?
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This is simpler but will not do series...
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If you use three jacks you can wire it like this.. https://www.tubesandmore.com/sites/default/files/associated_files/s-h700_plug_drawing.pdf
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mresistor; that's pretty cool. A bit complicated but every option is available. Thanks!
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Inspired by Slucky's diagram above I did another version using Cliff jacks that I'll call automatic stereo/mono wiring. The main difference is that you can plug mono into either side and get the same result; 4 ohms parallel. Maybe someone will find this useful.
The reason I'm trying to figure this out is that I run one pedalboard that is setup for stereo or wet/dry with 2 amps. My other pedalboard is more basic and mono. I have a new 2x10 cabinet that I'd like to be able to use with both setups. The only problem is my speakers are 8 ohms each and I don't like the mono parallel version bringing it down to 8 ohms. I should run 16 ohm speakers. Trying to figure a workaround.
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I made a circuit with a dpdt toggle swith that did most of what the s-h700 does and it worked great except the metal parts of the switch rattled with the cabinet vibration.