Want to build an amp/cab switcher - advice please

[Greg_L]

If the 7 switched jacks short when the patch cable is pulled, the you have the same safety rating that a typical amp head has for its speaker output jack. You could consider not using load resistors in this case.

The added bonus from making the patchbay is that (as pointed out earlier by John_H) if you have 3 speaker cabs, you could have up to three amps all plugged in and running simultaneously.

I'm a little envious at this point. My music room is cramped enough that if I have more than one speaker cab pulled out from the equipment closet (literally, a repurposed clothes closet) then there's hardly room to swing a guitar. Sometimes I have to move a cabinet out of the room temporarily to swap stuff around. sigh.

All of my amp heads are Marshalls....and one home-built AB763 clone as a head. All of my cabs are 16 ohm Marshall 4x12s. So yeah it takes up a lot of space, but I manage.

I use each head and cab for various things. I play live alot, I record myself and others pretty regularly. I'm a stickler for real sound, real amp sounds, really loud amp sounds. I record blazing Marshalls all the time. There is no "little studio amp" shit happening here.

As it stands right now, I use a bypassed Weber Mass 200 attenuator as a makeshift "patch bay". It's the go-between the amps and cabs. I have speaker cables connected to each head and each cab, and I just grab the amp cable and speaker cable I want and run them through the attenuator. It works, but it's a lot of reaching behind everything and....it's actually not that bad but I'd like it to be easier.

I'd love to have everything connected to one box at all times and I could just just move a patch cable like a 1940s phone operator. Amp B into cab D....no problem.

I could actually probably do without the dummy loads. I'm careful and I'm willing to take the risk. The way I do it now is also risky. I have cables everywhere. I could easily grab the wrong one and connect an amp that's not the one being used. But it doesn't happen. For all of my personality flaws, mistreating amps is not one of them. Knock on wood.

[Reader]

- - -So I'd need 7 dummy loads. Damn, that raises the cost and size and complexity. Good safety net though.- - -

For those who know more about the tube amp output circuits do the dummy loads for this project really need to be 100 Watt capable if they are just there to protect the amp in case of an temporary inadvertent hookup? Also, do they even need to be 16 ohm values? I ask this because I have run across discussions of amps that had internal load resistors at the output that were much higher ohm values. Something like 150 Ohms. The stated explanation was that the high value would still protect the amp and did not need to be as high wattage because of the high resistance value.

[mozz]

If you power down the amps when not using, you don't need dummy loads. You want simplicity of it, you don't get fool proof.

[Greg_L]

For those who know more about the tube amp output circuits do the dummy loads for this project really need to be 100 Watt capable if they are just there to protect the amp in case of an temporary inadvertent hookup? Also, do they even need to be 16 ohm values? I ask this because I have run across discussions of amps that had internal load resistors at the output that were much higher ohm values. Something like 150 Ohms. The stated explanation was that the high value would still protect the amp and did not need to be as high wattage because of the high resistance value.

They way I see it, 16 ohm would match what my cabs are and what my amps pretty much stay set to. Significantly higher resistance would be like an open circuit. Not that I'm too worried about it. I'm not going to crank amps into a no-load. I usually listen for the "hiss" to make sure I'm good to go before I go breaking eardrums.

[Greg_L]

If you power down the amps when not using, you don't need dummy loads. You want simplicity of it, you don't get fool proof.

I agree. The goal is not to have all of the amps on at the same time. I will still be powering on/off one at a time.

The dummy loads could be a good safety net if they're not too cumbersome or difficult to deal with. They're easy to find and fairly cheap, so what the hell.