Is this amount of record/tonearm bobbing "normal"
Most records sound fine, but a few of them (shoegaze, Interpol) with extended chords sound bad, uneven.
This could all be in my head. I'm new to this.
Kindly take a look at a brief video and tell me whether my platter is warped?
Hello, I would say this is going to be bad for the bearing. |
This is an age old problem with Td 124s. The table was designed for commercial use which meant immediate cuing of records which it does with a clutch that lifts the very light outer platter off the heavy inner platter which keeps rotating while the other is stationary. The outer platter is soft metal and can easily be deformed which is what has happened here. I hate to be the one to tell this to the OP but this is a terrible design for a modern audiophile turntable and should be kept aside as a interesting side path in audio antiquity. Time to get a new turntable. Do yourself a favor and steer clear of antiques. Get yourself a modern up to date design. If you do not want to see your tonearm bob at all get a table with vacuum clamping. |
Mijo, I don’t know enough about the workings of a TD124 to cast any doubt on your explanation of the mechanism of what we observe here, but back in the late 50s and early 60s the TD124 was the cat’s pajamas for any well heeled serious audiophile, not merely “made for commercial use”. They may have been used at radio stations too, but probably because of rugged construction. At audio salons in New Haven the TD 124 was slotted into McInosh and Marantz-based systems as a matter of course. |
Oh, I didn't pay enough attention, a TD124 you say! It is DEFINITELY the 'liftable' thin lightweight easily distorted cover that is slightly warped as mijostyn said. I LOVED mine, best BASS ever! EXCEPT, it's bearing is very susceptible to vertical movement, not good match for my too flexible floors. http://www.soundfountain.com/amb/td124page.html
Why a liftable platter cover? TD124's motor/bearing/lube need to warm up/loosen up, then you adjust the speed, then, every once in a while you re-check/refine it's speed, using the mirror showing the strobe dots on the underside of the main platter. More people join the party, room warms up, go check again! Clever 'no-contact- speed solution: Adjuster moves a shield that alter's a magnet's pull (more or less) on the underside of the platter to achieve perfect speed. It ain't direct drive, it ain't quartz locked. That cast iron platter weighs 4.5 kg (nearly 10 lbs), it's magnificently machined bearing, there is NO WAY it is warped. If it was misaligned to the bearing, it would be more pronounced than OP has. Remove the platter, drop it back into the bearing sleeve, go make toast, it might have dropped all the way down when you return. The clearances are so refined the air has to escape before the bearing can lower. Push down, it won't go. Just wait. First time you do it, you think something is wrong. During play, you do not want to turn it on/off, you don't want to wait for such a heavy platter with magnificent bearing to stop spinning, SO, their clever solution: a thin platter cover that you can raise/lower to disengage/engage the constantly rotating platter below. Raise, flip/change LP, lower lightweight platter down onto the main rotating platter, spin it does, instantly correct speed. Trying to 'fix' the slight warp in the platter cover may worsen it. Live with it's slight warp? Have a long peek at this, listen to specific frequencies on test lp https://www.vinylrecorder.com/stereo.html Know this: it is more important that your anti-skate is correct.
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