…from outer space ?
NO, this is not a post about replacing the corrugated suction hose on your vacuum cleaner or hoover. If you have a valve (vacuum tube) guitar amplifier consider yourself lucky because according to conventional guitar wisdom your tone will be rocking !!!!!!!!
Paul has written in asking about the best practices in replacing the vacuum tubes in his amp.
Try and replace old tubes with the same models from a new manufacturer simply because these tubes were more than likely built into your amp in the first place and from a part of the amplifiers response, although experts can probably help with using different tubes to gain differing tone characteristics.
Here are two great places to buy replacement vacuum tubes and find out more, including how they work. The tube store have a really handy page that can help you choose your pre-amp gain factor through using differing tubes.