Heybrook TT2 sub platter issue?

[shane]

Any luck with an arm yet, Bob?

[Developer_dave]

Not wishing to hijack but I have a similar question on my TT2 which I am in the process of rediscovering (it is a lovely turntable). On the first picture in the thread, the bearing well is off centre. Mine is also off centre and not sure if this makes a difference or not - presumably it changes the belt distance? When I centre the well manually, after I play a record and check it reverts to being close to the motor pulley as though the tension in the belt is pulling it over? I have taken the baseboard off and the springs were not in line with the red marks, they are now (although one had one red mark on the spring and 2 on the turntable) and the plinth and platter are level spinning about 3-4mm above the platter and the armboard is also level. One thing I was not sure about on the springs is how many turns to put on the bolts when initially compressing the springs, I guess they are down the bolt about 1 cm before turning back over and tweaking the levels. The platter bounces nicely, about 10 seconds when tested and with no twisting. The only lateral movement is when starting up the turntable for a second or so - maybe this is causing the chasis to move in the plinth? Any suggestions most welcome!!

[shane]

Firstly, to state the obvious, if the bearing is not in the centre of the hole that means that the whole bearing/chassis/armboard assembly is out of position, as this is a rigid assembly. The next obvious thing to state is that if you can see that the bearing isn't in the middle of the hole, then you haven't got the platter on, and two kilos of aluminium aren't compressing the springs into their normal operating position, so nothing's going to be in the right place, and the position of the chassis without the platter on is not important. What is important is what happens when the deck is fully assembled on a level surface. If the armboard is level with the edge of the plinth and sitting centrally in its opening, then everything is where it should be, and if you then get a good pistonic bounce with no rock or rotation, you've cracked it.

There are three factors that affect the way the chassis sits on its suspension, assuming that the springs and their rubber seats are in good condition. They are 1) belt tension, 2) spring position and 3) arm cable dressing. It's unlikely that the belt will have stretched much. It's quite a stiff belt under very little tension. Howeve, I have come across replacement belts that were the wrong length. That cocks things up completely, but assuming your belt is original, it's unlikely to cause any problems. The springs also are quite lightly loaded and are unlikely to have deteriorated, but their position is important. If you compress a coil spring it tends to lean over, and the red marks are positioned to take account of this. I'm at a bit of a disadvantage here because I cannot for the life of me remember why one spring on the alloy chassis had two marks, but it doesn't take too long to try that spring in both positions. By far the most like cause of problems is the arm lead. I don't know what arm you have but if it has thick inflexible leads (like most Linn arms for example) you will need to follow the setup instructions carefully. If yo don't have them you can download a copy from Vinyl Asylum. Good luck!

[Developer_dave]

Thanks Shane that is very informative. I will look again at the marks on the spring. It was late last night so I may have missed the second mark. The arm is a Linn basik plus. It only has one P clip and the cable is looped with a twisted cable tie/wire. It was set up like his by Creative Audio in Shrewsbury a long time ago... I will see if I can get a replacement p-clip because the manual shows 2, and dress it as per the manual although it does not appear to foul the arm board/plinth.

Other than that it bounces nicely is level and sounds wonderful, so I am not overly concerned and like you say once the platter is on it may we'll move back towards the middle anyway, Cant believe I didn't check that!!

[shane]

If it ain't broke, don't fix it! Although it contradicts the manual, there are many ways of setting up a TT2, or any other turntable. Before he set up Creative Audio, Dave Poole was the Heybrook rep (and a thoroughly good bloke) for the first three years of the TT2's life. He's probably worked out his own way of setting them up, so if it's working ok and bouncing nicely I'd leave it alone, sit back and enjoy the music.

Going back to your original post by the way, a bit of lateral movement as the platter spins up on switch-on is normal.