So here's the funny thing.  I bought my Heil PR-30 a couple of years ago, retired my old faithful Shure SM-57, played around with amp sims and condensor mics, dug-out the SM-57 and decided that I preferred it to the Heil, then decided I might need a ribbon mic.  So far so good.

_Now I'm currently mixing 2 versions of a cover song, one with all the guitars  courtesy of Amplitube and one with real amps. like the Tweaker in the pic with the PR-30.  I'm treating myself to tracking the solos this morning, and for a change I dug-out the PR-30 to run alongside a Radial J48 DI.  I usually track the amps loud. but when I'm engineering myself I'll run the amp fairly quiet (80-90dBA at 1m) whilst I get a starting mic position with headphones on.  Rather than try to play and engineer at the same time (I use different brains for these tasks) I'll plug my Line 6 Back Track into the amp with a guitar lead then I can wander around and listen whilst I futz with the controls.  This morning I was hand-holding the mic so that I could freely position it around the speaker and I decided that I could use a little more gain from the pre-amp.  I put the PR-30 on the floor about a meter in front of the amp and walked over to the rack to turn-up the pre - and nearly garotted myself on the trailing headphone lead. I took off the 'phones, undid the tangle and hit the button on the line 6 to start the test riff playing, put the 'phones back on and- nothing - they weren't working.  Then it dawned on me that the amp sound hadn't muffled - took the cans off, put them back on - same sound. Turned the pre amp up more and louder, same sound. You know when reviewers tell you that a mic picks-up the sound of the amp in the room?!?