Phantom + A90 question

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?