Tone arms

[jnorv]

What are the advantages of longer tonearms beyond the obvious lower tracking error? I have an SME 3009 S3 and it would appear to be fairly easy to mod the arm tube by replacing it with a longer tube. I can buy 12 Titanium tube from McMaster Carr and fashion a new head shell. I am wondering if it is worth the trouble? When I compare effective arm masses, my S3 is only 4.5 grams compared to 12 grams for the S 2 and 14 grams for the 3012 S2.

Jim N

[maxg]

This is not going to sound good but it is not the length that matters so much as the mass.

Lets clarify that we are talking about tonearms so the snickering can subside. What we are talking about is the match of tone arm to cartrdige to keep the resonant frequency of the setup at the right level - in other words between 9 and 15 Hz (9 to 11 better).

Your current arm is a low mass design - the new, longer ones, are medium to high mass. Assuming your current cartridge is a good match to your arm it is unlikely to be for a higher mass arm.

There are a few formulas out there to establish the resonant frequency of a cartridge/arm combo. The one I use is:

Resonant Frequency = 1000/[6.28*square root (M*C)

Where M is the apparent mass of the arm and cartridge combined and C is the compliance.

Do the maths before you buy - unless you are planning to get a new cartridge anyway.

Note : Just because the math works out does not mean your cartrdige and arm are a good combo in reality - it is just an indicator, but if they are out it usually does spell trouble.