Phantom + A90 question

How ahve users of this combination dealt with the inability of the Graham headshell to touch all three contact points on top of the A90? I'm considering the use of a carbon fiber shim from Millennium, pre-drilled with holes for the cartridge screws, between the cartridge and headshell to provide full contact. Think it's needed? Any other solutions? Is it even a problem?

I have no help to contribute here, but feel your pain. I had a hard time even getting a Koetsu secured flat to my 10" armwand. The fact that it rides way back in the headshell for proper overhang causes issues due to first the blue dot (which I removed) and then the slightly raised "rails" flanking the screw slots -- either can result in torquing forces (and thus mess with VTA / SRA) when too far in front of the mounting point.

I was thinking the other day that if I ever wanted to try an Ortofon Cadenza / Kontrapunkt, whether those 3 points (really 2 points and a rail) would cause a mounting issue in absence of the blue dot.

I don't see discussion of the Graham's headshell, but so far I feel like this is the one less-than-brilliantly-designed piece on an otherwise superb and very universal arm. Will be very curious to hear your results!
The mounting issue with the Cadenzas, as with the A90, is that the rear-outside point just hangs in space. Definitely the meeting of some quirky designs from both Graham and Ortofon.

My Ortofon dealer recommended sanding the raised bar and points off the plastic-bodied cartridges like the Cadenzas. He says it's easily done using adhesive sandpaper on a flat surface, although I'd be a little wary. The metal-bodied A90 is an altogether different story.

I think I'll try using one of these spacers. They're of varying thicknesses and I'll experiment. Carbon fiber may introduce its own sonic signature, but at least that rear point will be supported. I'll let you know.
Isn't the cadenza the same body type as the Jubilee? This is the first I have heard of a quirky design...
Isn't the cadenza the same body type as the Jubilee? This is the first I have heard of a quirky design...
Any cartridge (or headshell) with a non-flat mounting surface is potentially quirky. For a manufacturer to offer two such models isn't less so, it's doubly so.

Owners who wish to reduce cartridge/headshell contact can use aftermarket, point-contact spacers. The 3-pointed ones from Mapleshade can be fitted with the single point toward the front or the rear, which doubles the chances of a fit. Accordingly, they may be regarded as semi-quirky.
I am going to take a closer look at my A90 mount. It didn't even think it was an issue. Perhaps a can of worms is now open, perhaps it's a non issue. My sound has been fantastic with the Supreme/A90 combo and the Supreme/Coralstone combo. I use a Foz for azimuth setting.
I don't believe I have an issue with my Jubilee mount, azimuth looks spot on to me and the sound has been great for 3 has been so long I can't recall how I dealt with it but do remember mention of it in the mounting instructions from Ortofon. Having a hard time remembering what I had for breakfast for that matter. LOL!
It may well be a non-issue in practice. With the front-center and rear-inside points touching the headshell along with the two screws, that's four secure points of contact, which is probably enough to maintain adequate rigidity. If the inside screw is tightened first, the cartridge shouldn't tilt when the outside screw is tightened, although over-tightening it would create countervailing pressure, if not torque, on the cartridge body. Any slight tilting could be corrected with the Phantom's easy azimuth adjustment. Still, the idea of one point out of contact bothers me a bit in theory, so I'm curious whether others have taken measures.
Hi bill,
With unipivot bearings, they visually ride the groove different from gimble, quote on quote level heads shell with gimble type arms. You need a fozgometer to get it right with a graham, IMO. So even if the mate between cart and head shell isn't exact, you will correct that anomaly via Foz azimuth or o scops, graham head shells tilt inward by 2-3 degrees from vertical, ime
Hi Rockit,

I'm with you and use a Foz for azimuth, so I'm unconcerned about that aspect of any tilting. The nagging question for me is the solidity of the connection between cartridge and headshell. I'm getting the impression, since no one seems to have taken measures, that it's really not a problem. When my upgraded Supreme and rebuilt A90 arrive (tomorrow, fingers crossed), I'll try it both ways and report back.

I wondered about the same thing when I was using the A90 with the Phantom. In my setup two of the ridges are in contact with the Phantom headshell while the left rear ridge is completely outside the headshell area - see this pic.

The same situation existed with the Ortofon Jubilee in my setup.

In practice the A90 sounded great and I doubt contact with the third ridge would have altered the sound - at least with an arm having easy azimuth adjustment like the Phantom.
Nice pic, Tobes. I'll relax about mounting the A90. Seems like a non-issue. Thanks.
I doubt contact with the third ridge would have altered the sound - at least with an arm having easy azimuth adjustment like the Phantom.
With resolving components like this, changes in cartridge/headshell contact always alter the sound - even when azimuth remains constant.

Don't take my word for it. Try changing your mounting screws from stainless steel to brass to nylon - without altering azimuth or any other parameter. I guarantee you'll hear differences.

Think about how a phono cartridge works: anything that vibrates the coils or magnets generates a signal (or alters a signal being generated by other vibrations, such as those induced by record groove modulations). Stray vibrational energies within the cartridge body feed back into the armature and magnets, distorting their movements and therefore distorting the original signal. So, changing the behavior of these energies will alter the sound of the system.

The behavior of stray cartridge-body vibrations is heavily influenced by cartridge/headshell contact, as the screw material experiment mentioned above easily demonstrates. Altering the number, size or placement of cartridge/headhsell contact patches also alters those behaviors. Ortofon chose 3 contact points because they believe this cartridge sounds best this way.

I've no idea if Ortofon was right, if 3 contact points sound "better" or "worse" than 2 or 4 or a flat surface - but I guarantee they'd all sound different.
Doug, you may be right but its not something I ever lost sleep over when I used the A90 with the Phantom.

The A90, and other similarly designed Ortofon cartridges, actually have 5 contact points when you think about it - the 3 raised ridges + the 2 fixing bolts.

I agree that every small change makes a difference with analog. Some are for better or worse. Some are just different and it could be argued either way depending on the ear of the beholder.

I suspect the OP's suggestion of a mounting plate would sound more 'different' than omitting the 3rd ridge (since it introduces another material/interface) - but only the ear could decide which is preferable.
I've just finished a nightshift and my thinking may be faulty but....

I seem to recall that the idea behind the ridges on the Ortofon MC's was to allow for azimuth adjustment on arms that didn't provide that adjustment - ie tightening bolts such that the cartridge canted either side of the central ridge.

This would be tedious in the extreme to actually achieve proper azimuth, but in any case, wouldn't tightening towards one side inevitably lift one of the rear ridges away from the headshell?
Interesting idea, although a single ridge on the centerline of a cartridge is superior for azimuth adjustment, as it only allows the the cartidge to rotate about one axis. I've used that method on tonearms which lacked azimuth adjustment. It wasn't any more tedious than using the adjustments on some tonearms, though other arms make it easy of course.

My guess (only) is that Ortofon wished to minimize contact between cartridge and headshell for resonance control reasons, rather like the 3-point Mapleshade isolator, and didn't consider the quirks this might present for small headshells like the Phantom's.