unplugging guitar before shutting off amp?

I do it all the time, never had a an amp give up on me, is it bad? a buzz and click, sounds horrible when you do it but i never knew it was bad for the amp, one tip on amps, if you own a Valve amp switch it off and allow it to cool off for a while before moving, when the output valves a red hot they can be very fragile and clanking the amp around can damage them, look out for that all you Mullard rubbing virtuoso's. I always switch my amp off after a gig or rehearsal, and then pack everything away and load up my car and then go get the amp.

GeeGee, bear in mind I'm not an elecspurt. What little I do know revolves around sniffing Mullards :) . Any IEEE type looking in would do everyone a favour if they chimed to contradict me...

AFAIK, you're right in that pulling the jack from your git doesn't worry the amp; it's your speakers you are risking. The tip of your jack sends the 'hot' signal and the sleeve goes to ground. By pulling the jack out, you momentarily reverse this. Correct me if I'm wrong, solder-monkeys, but the guitar's passive circuit means that the amp does a "so what", but amplifies a brief, high amplitude, low frequency "dur" noise.

This goes straight to the speakers and, if there's one thing they don't like, it's a low frequency square wave. Much shredding of cone from the rubbery surround bit, and subsequent farty noises.

I don't switch off the amp before pulling my 1/4" ( :shock: ) but I do roll the amp vol back to zero. Keeps the speaker sane (flicking to standby has the same effect). The preamp gets, and amplifies, that "dur" but the speakers receive Butkus and all is happy. At least, that's what I go by. Any other ops?

I bet a lot of people have done this. Getting no, or a crackly, output you yank out the jack from the guitar and tap your thumb on the tip a couple of times. That "dur dur dur" noise comes from you grounding out the tip - quite OK at low volumes but a bit unpopular at gig levels.

I've done something I reckon most haven't, and I wouldn't recommend it. Getting no "dur dur", I wondered if my amp-cab cable was duff. Innocent teenager that I was, I pulled the jack out of the speaker cab and thumbed it. Now, this is a bad idea for the amp anyway. The output impedance has gone from a nice 8ohms to something like infinity and the tubes and output transformer work like burgery to make up the difference. Much amp-smoking if left too long.

More importantly, I wasn't touching the tip of a passive cable carrying no current. I'd stuck my thumb onto the tip of a lead carrying all the horses of a 100W valve amp, expected to turn around some pretty big speaker magnets. The rest of the band looked on, bemused, as I did a high-speed version of Ricky Gervais' dance from "The Office". I finally managed to fling the cable out of my grip and, a few seconds later, stop my arm flapping :oops:

In any case, what made me think I'd get a "dur" noise when I'd disconnected the speakers? :roll:

Phew - :D . I wondered just how far "The Office" had spread as a TV show. Could've been a bad simile, but I got away with it. Don't try it for yourself, though.