I'll give that a shot. Its supposed to be able to handle an amp's output Did anyone else see this?
DI boxes are for guitar input not amplifier output, no wonder it was clipping.
Radial does make a special DI for amp speaker outputs.
There's no advantage to using a DI over plugging in directly to your interface.
DI boxes are for converting hi impedance to low so you can send a balanced signal over a longer run of cable. If your sitting within 20' of your interface there's really no point in doing this. Most interfaces have a hi z input.
But if you want the tone from your amp..
Put a mike on the speaker ( best) or use said Radial ( or?) speaker emulator box.
Some amps now have pretty good speaker emulator outputs ( Vox , Blackstar, Line 6 )