I have a very old amplifier (Marantz Model 140). It has been working very well for almost 20 years. Yesterday when I switched it on, the speakers came with a continuous, very, very loud "wool" / "wow" sound, and the power indicator on the amp showed that it had reached the maximum power. The whole thing just terrified me. I wonder what the problem is. Is it because of a kind of 'short-circuit' between the contacts of speaker cables? Does anyone experienced this before? Will it harm the speaker? I would like to know how to fix the problem before turning on the amp again cos I have no idea if it will do irreversible damage to the speakers ...
The amp is dead - probably a cap somewhere. It may be cheaper to buy another than to have it repaired and yes, it will harm your speakers (and the amp).