VPI Aries - either or question, please comment

I agree with Plato that you would be better off with the 9" arm and the TT improvements. The TT/motor assembly is higher on the analog hierarchy scale, and will make more difference than the longer arm will.

The only differences that the longer arm makes is an extremely slight reduction in tracking error, and slightly higher mass that may be a better match with certain cartridges.

You can try to use a Shelter on it, and I understand that Harry has supposedly done something to the arm that he claims will make it handle a Shelter.

If it were me, I'd use a different cartridge on that arm.

The technical reasons are that unipivots, with some exceptions, notably Graham, WB, and Nottingham which have stabilizers, are inherently unstable platforms due to the nature of the single pivot design. When using higher compliance cartridges, this is not much of a problem, if any. When using lower compliance cartridges, such as Shelter or Koetsu, there is significantly higher energy fed back into the arm by the stiff cartridge suspension. This causes the arm to move about in ways that is not good for retrieving the sound. Of course, the cartridge will work in this system, but it loses much more than a similar quality gimbal arm would. Some people don't care about this, and do it anyway, and seem to be satisfied with it. If that is the case then I'm happy for them. I am just pointing out the fine details of proper cartridge matching that goes beyond mass/resonance. Maybe Harry has come up with something that will work with the Shelter. If you want to use a Shelter in a JMW arm, then I'd recommend that you call VPI and ask them directly if the JMW-9 you are getting is an ideal match for a Shelter 501 or 901, or not. If they say it is, then it is on their heads if it doesn't work right. I'm just trying to look out for your best interest by pointing out a possible problem before it becomes a problem for you. I know that they commonly recommend, and even sometimes package Dynavector cartridges in their tonearms. It seems they think that a Dynavector is an ideal match for their arms. A Shelter and a Dynavector are worlds apart in terms of compliance. If VPI says it's ok, then go ahead. If not, stay away.

Dennis, a periphery clamp is a large ring-shaped weight that goes on the outer edge of the record, to hold the edges down during play. It helps to "iron out" some warps, and to better couple the record to the platter, as well as possibly damping out some unwanted resonances and adding additional rotational stability to the system by adding weight to the outer edge of the platter. It has some merit, but adds difficulty in changing records, because you have to take it off, and put it back on with each record you play.