Tube amp going through a busted cab

[mydog213]

I know you are not supposed to use a tube amp without a speaker load, but say if the speakers are busted and I want to record directly from my amp. Is this okay?
Were running the signal from the tube amp to a box.

 

[gareth dunster]

Try it. If your amp emits smoke and sparks it was probably a bad idea.

 

[dhsierra1]

I know you are not supposed to use a tube amp without a speaker load, but say if the speakers are busted and I want to record directly from my amp. Is this okay?
Were running the signal from the tube amp to a box.

if the speaker is shorted it wouldn't present any load to your amp so it'd blow.

You can find 4 and 8 ohm power resistors up to 50 or even more watts pretty easily. Try Parts Express. That'd be the safest bet.

Edit: There's amp boxes that'll let you plug into a board w/the amp's output, I'd look at one of those. Those will present the amp with the proper load and attenuate the output so you can just go right into a board. Behringer (I know, it's the B word ) and others make them.

 

[Mr. Foxen]

If speaker is shorted, thats probably OK for a while, its if its open then it is trouble. Basically, it isn't a goer. If you want to record direct from the amp, run it with the power valves pulled out if its a preamp DI, if its a post power section DI, then you need a load, and a speaker presents a different load to a resistor, so is part of the sound. Mic it up.

 

[dhsierra1]

If speaker is shorted, thats probably OK for a while, its if its open then it is trouble. Basically, it isn't a goer. If you want to record direct from the amp, run it with the power valves pulled out if its a preamp DI, if its a post power section DI, then you need a load, and a speaker presents a different load to a resistor, so is part of the sound. Mic it up.

I understand speakers present impedance and reactance, so hooking up a power amp to a purely resistive load is unsafe?

I've seen a number of amp techs do this to check out tube amps, and guitarists use power amp soaks based on using large power resistors, am I missing something here?

 

[Mr. Foxen]

Not so much unsafe, it just won't sound the same as a post power section DI with a speaker if there is a resistive load. But a broken cab is not a suitable load, because you don't know what sort of load it presents.

 

[dhsierra1]

Not so much unsafe, it just won't sound the same as a post power section DI with a speaker if there is a resistive load. But a broken cab is not a suitable load, because you don't know what sort of load it presents.

gotcha, thanks