Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dsones on June 10, 2025, 04:37:46 pm
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My vox ac15c1 amp has the amp out wired directly to the speaker. I want to be able to use an attenuator. I want an amp out jack and a speaker in jack for when I use an attenuator. I want to wire the jacks so when an attenuator isn't used the amp out automatically connects to the speaker. I see instructions on how to add an amp out jack and speaker in jack to connect an attenuator but if you don't use the attenuator you have to use a jump cable to connect the two jacks. I would like to not use a jump cable. Any ideas or wiring diagrams out there? Thanks
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Do you have a diagram of how your attenuator should be used?
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Weber does a range of off the shelf attenuators https://www.tedweber.com/gadgets/attenuators/ (https://www.tedweber.com/gadgets/attenuators/)
Or you could wire in a double throw switch with couple of chunky 25W ceramic resistors for a 1/2 power switch (as on the Fender EC Tweed Tremolux)
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This is definitely possible but id say KISS: find an attenuator with a bypass.
If you still want to wire up switching jacks, find an attenuator youd like to use and post it here.
Wiring in resistors on a switch is also not a bad option since its only a 15w amp.
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A Weber Mini Mass attenuator would be a perfect fit.
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...but if you don't use the attenuator you have to use a jump cable to connect the two jacks. I would like to not use a jump cable. Any ideas or wiring diagrams out there? Thanks
It can be done with a standard type of switch fitted on the back to 'jumper' the in and outs together when not using an attenuator, but then if the switch was ever accidentally on at the same time as using your attenuator [or somebody else used the amp without knowing] it would run the speaker and attenuator in parallel which could be very bad for the amp?
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It can be done with switching jacks, but the contacts are not great for high currents and tend to oxidise, becoming unreliable over time. So like other have said, a proper switch it better.