3xxx mvmt Woody woodpecker ting ting sound

[Dr Rock]

Yes, I know, what the hell is that title all about?

Well, it's all to do with the sound of a Rolex movement ticking. On the 15xx movements it is a nice, slow 'tick tick tick' sound. On the 3xxx movements the beat is much faster, 'ticker-ticker-ticker-ticker'.

But, there is also another sound on the 3xxx movements: it's a pinging/tinging sound that goes in and out of phase a bit, at about the same frequency as the ticking.

Anyone know what causes this? I'm not concerned, just curious!

Fraser