Don't agree Keef.

I run a regular "acoustic blues" jam with modest use of a PA (OK... maybe we crank it up a bit at the end!). It hasn't prevented audience participation at all and audience ambient noise at such events tend to be a little more than when a knowledgeable and reverential folk audience is listening to, say, Martin Carthy or a classical audience as in Wilfried's Segovia example.

At the trad session I run in the same venue, it is always unamplified and those who come to listen to that are generally aware of, and sympathetic, to that.

The problem comes, and I have run a folk club in the UK in the past for five years, in the type of situation WLD describes. There is, unfortunately, a habit/tradition at some FCs (but by no means all) of noisy heckling as I mentioned above. In those situations, light use of a PA can be useful if the venue demands it. I certainly do not want to lose my voice or trash an expensive instrument because of some ignorant noisy bearded wazzocks in the audience.

RS