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I want to A/B a setup that would be a Henriksen Bud Six into a Raezer's Edge Stealth 10 and a DV Mark Little Jazz into the same extension cabinet.
Can I run a Y-cable from the extension cabinet to the output of both amps and then have my A/B pedal switch between amps as usual, or does that not work? If it doesn't work that way, I was also thinking maybe a dual A/B pedal setup with one between the guitar and amps, and then another A/B pedal that's between the amps and extension cabinet. I'd rather not have to use 2 pedals if not necessary.
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04-26-2026 11:10 AM
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Switchbone V2 - Radial Engineering
I got an earlier version of Radial's BigShot EFX (true bypass effects loop switcher - two loops, independent ground lifts, mute) a long time ago. Build quality is superb, indestructible, etc... they make seriously pro level nice stuff.
Their amp switcher is one of their oldest products, evolved to actualize any situation and mitigate all problems.
You should use the Radial solution as the best reference against anything else you might entertain using.
Just to be clear, solid state power outputs don't mind being "open" at all but may be quickly destroyed by shorted outputs. Tube amps are OK with shorted outputs but may destroy themselves seeing no load (open output). These and other considerations are why amp switchers and cab switchers aren't simple switches - the change needs to be done in a way that avoids certain risky conditions to the equipment.
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If you have an A-B switch that’s designed & built to handle the output voltage and current of an amplifier, you can use it. But standard A-B switches are designed for instrument level signals. The speaker A-B devices also have internal loads to avoid driving the “off” amp without a load.
You may be able to use a simple 110V DP/DT switch. Both of your amps should be safe without a connected load. But check with the manufacturer to make sure, if you want to stick one in a little box with 1/4” jacks.
Radial used to make one, but it was fairly expensive. IIRC, it’s cheaper to buy a second cab and use an A-B switch on the inputs.
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I'm glad I asked, I didn't realize there was more involved for the safety of the equipment. Thank you for your replies.
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It’s a Bad Idea. I’m not even sure what connecting the output of two amps together with a Y-cable would do (which is in fact what you would be doing). A switch, to do it properly, would have to have a dummy load for the unused amp, and somehow be noiseless - you don’t want a loud pop when you switch.
If for some reason you really want to do this, get a cabinet with two speakers, each with its own input, and switch between amps. Other than schlepping one big box instead of two small boxes, I don’t know what this would get you.
jmho
steven
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Originally Posted by stevo58
Never connect the output of an amplifier to another amplifier's output. Connecting two amplifier outputs together puts the output impedance (the impedance of the amplifier’s output stage, not the speaker impedance) across the output of the other amp in parallel with the speaker load. The output impedance of a class D amp is almost 0 - they run from a few hundredths of an Ohm to a few tenths. This is essentially a short circuit across the output, which sees the other amp’s output impedance as part of the speaker load. This will trigger output protection circuits to shut down, since neither a Bud/Blu nor a Little Jazz will drive a load well below 1 Ohm. Amps with no output protection will blow a fuse and or their output devices trying to drive a short circuit.
Even if by some miracle you have an amp that will actually drive so low a load, the frequency response would be so wildly off and the distortion levels so high that it'd be unlistenable.
BTW, the very low output impedance of a class D amp gives it a very high damping factor. This is a big reason for the tightly controlled bass that characterizes their sound. One reason for the fatter, looser bass of most tube amps is their low DF.Last edited by nevershouldhavesoldit; 04-28-2026 at 11:30 AM.
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This is a very bad idea for a bunch of reasons. Best option is to buy a second cab and use the AB switcher between the guitar and the two amps.
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Why would you want to do this in the first place? I agree just run two separate rigs. Or perhaps just get another preamp to run via the effects loop as an option.
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It’s such an obviously wildly bad idea, it never occurred to me to even think about it. Originally Posted by nevershouldhavesoldit
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In the same vein, I always wonder about a setup I would like to try....but I think I know the answer!
Not guitar amps, but to connect two stereo receivers to one set of speakers (NOT TO BE TURNED ON AT THE SAME TIME) might cause similar troubles. One amp would "see" the other amp's wiring and OT as something it should not see.
Am I right in this conclusion? I want two different receivers to use one set of speakers - out of convenience and space restrictions.
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SS amps have output impedances of well under half an Ohm when operating. When off, the passive resistance of the components may be significantly higher than that of the speakers it's intended to drive, depending on its design. So it could be safe to connect 2 SS amp outputs to the same speaker, if you never ever accidentally turn both on at once. It's still going to affect the frequency response and dampling factor enough to cause possibly audible effects. It's a bad idea. Originally Posted by Jimmy Mack
OTOH, the output impedance of tube amps is the passive resistance of the secondary winding in the output transfomer when turned off. This is almost always an Ohm or less. In parallel with an 8 Ohm speaker, even a 1 Ohm impedance would reduce the load to 0.89 Ohms. With a 4 Ohm speaker connected, the load would be 0.8 Ohms. So it would not be safe to connect any amplifier's output in parallel with a tube amp's output.
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