Alun, first, congratulations on your new turntable. The TNT 6 is quite a step from the Jr. Second, you should not have distortion at the inner grooves; what you're experiencing is not normal and should/can be fixed. But, the cause of the distortion can be a number of things, with the top candidates including: record wear from some other time and place, misalignment, or a cartridge wearing out.
I used an ETII for many years and continue to admire this tonearm. Start by making sure it is aligned correctly on your new turntable. If it is accurately aligned, then double-check the vertical tracking force on your cartridge, keeping in mind that a little heavier is better than too light (a little experimentation is useful here). If the alignment is spot on and tracking force is where it needs to be, then consider whether your cartridge could be getting old and the cantilever suspension hardening up in it.
And one further thought: does the arm float freely and easily all the way across the record when you put it into a neutral balance? I'm sure you're aware of properly dressing the tonearm wires after all these years, but also make sure there's no contamination build-up that might be causing some binding of the arm at the end of its travel through the manifold.
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I used an ETII for many years and continue to admire this tonearm. Start by making sure it is aligned correctly on your new turntable. If it is accurately aligned, then double-check the vertical tracking force on your cartridge, keeping in mind that a little heavier is better than too light (a little experimentation is useful here). If the alignment is spot on and tracking force is where it needs to be, then consider whether your cartridge could be getting old and the cantilever suspension hardening up in it.
And one further thought: does the arm float freely and easily all the way across the record when you put it into a neutral balance? I'm sure you're aware of properly dressing the tonearm wires after all these years, but also make sure there's no contamination build-up that might be causing some binding of the arm at the end of its travel through the manifold.
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