would this work?

[KeithRT99]

could i take the fx send from my 5150 combo and run it direct without doing any damage?

 

[Razorjack]

You'd still have to plug your amp into a cab, just to make sure. I can't say it'd sound too great but it's worth a try.

 

[Disconnekt]

Ditto to what Razorjack said. Make sure the speakers are plugged in so you don't fry your output transformer. You'll probably want to run some kind of cab simulator on the direct signal because it's going to sound like a buzzsaw. Also, to get a decent signal level on your recording device, you're going to have to crank the post volume pretty much all the way, and if you don't patch anything into the FX return, the signal will still pass to the speaker, which will be ridiculously loud. I've tried this before and I get the best results dead patching the FX return... a little bit of signal still gets to the poweramp, but if you put pillows or something in front of the speakers you can barely hear it.