Sounds light on bass

[Marco]

I'd agree with Mark.

Whilst Martin is right to question David's inability to get things properly level, the issue David has is much more to do with the inherent sonic signature of the AT (no matter how well set-up) than any set-up deficiencies themselves, which would impact on the sound in a rather different way to what David is describing.

Marco.

[indus]

Yes I'm doing it with a non spinning record as mentioned. There are only a limited number of things you can do to get it level

1) Adjust the vta. This doesn't resolve it.

2) Twist the headshell slightly. This doesn't resolve it either. I've read people talking about twisting the cart itself but I really can't see how this works. Once the screws are done up the cart will only sit in one position securely.

The tonearm spirit level implies that (as you look down the 'barrel' of the cart/arm) that the left (inner) side of the cart is higher than the right (outer) side of the cart.

But I cannot see how I can resolve this


Edited to say there is one thing that springs to mind that may have caused this. I lost one of the original nuts that go on the bolts supplied with the headshell to hold the cart. So I sourced one from elsewhere. It fits perfectly and looks the same thickness to the naked eye. Could it be that it's thickness is marginally different?

[Marco]

David,

You need to adjust (raise/lower) the feet on the turntable and/or the support table/rack it's sitting on, along with the other things you mention, in order to achieve what you need.

The first thing you should always do is ensure that the T/T is 100% level on the support it's sitting on, and THEN take it from there with the other adjustments.

Marco.

[The Grand Wazoo]

Crazy thought, but is the bottom of your spirit level at 90 degrees to the vertical when it's placed on a known level?
Put it on a surface, rotate it & try again. Is the bubble in the same place or not?

[YNWaN]

Would you care to elaborate?

Well, the mounting plane relative to the fixing centre (of the headshell) is not very different from one headshell to another - at least, it is within a couple of mm and this should be easily compensated for by adjusting the arm height. I just don't see headshell differences being all that influential in this instance.

[MartinT]

Yes - Marco & Chris are right: the turntable must be absolutely level to start with, and the spirit level must be true (bubble stays true when the spirit level is rotated 180 degrees).

If the headshell won't twist correctly after that, it may be that its socket is not true to the surface of the 'shell. This would indicate an assembly issue.

[indus]

Marco, I put another spirit level on the platter and did just that. The deck is 100% level according to this reading.

Chris, thanks, will check that.

Thanks

[YNWaN]

If the arm appears to angle down towards the headshell you need to either lower the back of the arm or, if it is already at its lowest setting, fit a spacer between the headshell and the top of the cartridge body (longer bolts may be needed).

[Macca]

Well, the mounting plane relative to the fixing centre (of the headshell) is not very different from one headshell to another - at least, it is within a couple of mm and this should be easily compensated for by adjusting the arm height. I just don't see headshell differences being all that influential in this instance.

Which is what I thought but I don't have this issue with the two other headshells I have tried one of which is the stock Technics. Both allow enough room to have the assembly level, tail up or tail down. Has to be Sumiko-related.

EDIT I am going to try to asses level another way on the assunption my spirit bubble isn't true.

[YNWaN]

This whole thread reminds me how difficult it is to identify and resolve issues like this at a distance. So often the answer lies in something the OP has omitted from their description (often because they don't believe it relevant or don't appreciate its relevance).

We don't really know what the frame of reference is when the OP complains of reduced bass. As Marco writes, it could well be a fundamental issue regarding the tonal balance of cartridges. It could also be a VTA issue, but this would be a much more subtle difference. For a start, I would like to know how far off horizontal (parallel) the armtube is to the record surface - a picture of this would be helpful.