Just realised I am always accused of being too obscure, and I originally posted this quiz in a thread entitled "Hifi Choice wanted" and I couldn't work out how to edit its title so I have moved it here
Many many thanks to Angus for supplying the article. I remember now why both Arthur and I burned ours - it was the start of the dreaded "dynamic wow" bollocks. However, the bit I wanted is helpful, and Mrs S now has a bit of a better idea about why things like arms, mats and turntables make such a huge difference to how music from a record player sounds. (I wonder just how much even this simplified analogy is really understood by her - she's got a number phobia, and still regularly asks me questions like is 5 out of a 100 5%?)
I thought I should share the love - and help enlighten a few more why there is more to it than changing the wires in the arm. But we'll start with a quiz. I'd offer a prize, but I'm too tight and have nothing to give away - even that Linn basik cartridge has sentimental value. Anyway it would only encourage the most despicable cheating - and you should follow the Olympian spirit and compete for the sheer honour and glory. If you KNOW the answer, either because like Adam, you have the article, or because you are an engineer and good at sums, please don't spoil it for the rest. Post "I know it" and PM me for confirmation and public acknowledgement. A cartridge is an electrical generator. The stylus on a cantilever moves relative to a fixed cartridge body. It either moves the coils of the generator relative to the fixed magnet (moving coil) or moves the magnet of the generator relative to fixed coils (moving magnet). I don't need any smart-arse bringing up Decca London, or piezzo crystal cartridges for the sake of this quiz!! The key is the stylus needs to move relative to a fixed cartridge. If they both move by the same amount in the same direction, there is no output. If energy is moving the cartridge body relative to its supposedly fixed position (or moving the stylus other than as intended by the groove) you get a false signal. So, converting the Colloms scale to metric (The scale works for distance size only and not mass)
The tonearm is pivoted nearly 6 and a half kilometers from the stylus tip. The arm is 400m above the record surface, and the cantilever is 85m long. A 50Hz (mains hum) organ pedal note played loud requires a left to right (peak to peak) lateral movement of the stylus in the groove of 3200mm (That's a yard and a bit Gordon). (This is near, but not at the top of the movements a note would make the stylus move)
1) what is the lateral movement for a 10Khz violin harmonic at 50db less (not by any means the smallest note a gramophone needs to reproduce - but near that end) ?
2) How much is the vinyl groove itself squashed by the mass of the cartridge? (so - how much is it really squashed by the real mass - scale up the dimensions)?
Maybe I could persuade Marco to confer the title of "Official AOS clever clogs" on the winner by way of prize