Harp Attack through PA

Hi there!

This is not a beginner's question, but could be fairly useful to everybody on this site. Let's bear in mind that lots of great players used to play or played harp through the PA (Junior Wells, Sonny Boy, Little Walter), so I wonder how convenient this could be nowadays. Back in the day, they were all tube PA systems, so getting a nice warm tone wasn't much of an issue. However, there are now loads of different pedals and tube-powered mic preamps which could work just fine... Also, in his late years, James Cotton played a cupped SM58 into the PA (no tubes, apparently) and his tone was second to none.

The thing is that there are sometimes Jam sessions or short showcases when bringing an amp seems a bit too much work for the stage time one gets, so having one of these back-up tricks up in the sleeve would be handy.

Here on Bluesharmonica.com, I've seen a video, with David Barrett and Ryan Walker in it, in which the Harp Attack pedal was discussed and used to make a solid state amp sound better. According to LW, the Harp Attack was primarily devised to plug your bullet mic straight into the PA and get a tube-driven sound...

Does anybody know David Barrett's opinion about this use?

Thank you!