Best cartridge for very old worn vinyl

@chakster many thanks for that - so is this how I get the alignment right for the FR7/SPU cartridges?
1. Buy Dr Feickert Protractor.
2. Choose Stevenson alignment point.
3. Adjust FR66 with FR7 attached so that it aligns on the Steveson points.

If I use the Brinkman alignment tool (based on Baerwald alignment I gather) and follow the above the FR7/ SPU won’t be correctly aligned - is that right ?

Many thanks 
Howard 

Yes, Feickert is good to have for any situation.
First lock the PS distance recommended by tonearm manufacturer, then you will see that your FR7 or SPU will reach Stevenson point (step-1), for the step-2,3 you can rotate the protractor on the platter if needed. 

Baerwald alignment does not work for headshell integrated cartridges like FR-7 and SPU on Fidelity-Research tonearms. 

@chakster  thanks again.
Apologies for what might be dumb questions but my technical understanding hovers around zero on a good day ...
Supposing you could adjust either the FR7 or SPU in the headshell like most other cartridges. Would it then also be the case that only the Steveson alignment worked with them ?
What I don’t quite understand is this : a stylus, whether it’s in a Lyra, Koetsu or SPU (apart from having different shapes/lengths) does the same thing, ie sits in a vinyl groove and moves across from the outside to the inside of a record. It’s a mechanical operation.
If the stylus in (say) a Koetsu can work fine in (say) the Baerwald alignment  on an FR66 then why would the physical mechanics that enable the Koetsu stylus to get across the record well not also allow the stylus on an SPU to do the same (assuming the tonearm is adjusted so that the SPU is aligned in the same way as the Koetsu).
Best regards 
Howard 

You can’t adjust overhang on cartridges like SPU or FR7 series, because they are headshell integrated (as one piece). The overhang is fixed by the manufacturer and you can;t altering the stylus position without altering PS of your arm. Pivot to Spindle distance is given by the tonearm manufacturer and it must be exactly as the manufacturer suggested (it’s in the manual for each tonearm). But Fidelity-Research is the manufacturer of both (tonearm and cartridge), when your PS is correct your stylus position is also spot on (and you don’t have to adjust anything else), but only for ONE alignment method chosed by the manufacturer. Ikeda designed his arm and his cartridges using Stevenson alignment (just like the majority of the Japanese manufacturers).

The difference between Stevenson and any other alignments is null points. Since the arm is not Linear Tracking there are only two ideal points across the record surface for your stylus, the rest is off.

When you will buy Linear Tracking tonearm the stylus is always spot on across the whole record.

For pivoted tonearms there are only two null points, and the difference between alignment methods is where they are on the record surface.

If you are using conventional cartridge and headshell with slots then you can re-align any cartridge for any geometry (Baerwald, Stevenson, Lofgren or whatever) without altering the PS, you will have to twist your cartridge in the headshell, overhand will be different too for different alignment methods.

Dear Howard,

With the SPU the distance from the collar (of the headshell) to the stylus tip is exactly 51mm. Ikeda clearly designed the FR7 with the SPU in mind and chose that same distance. This is why both these types are correctly aligned to Stevenson geometry when the arm is installed with the P2S specified by FR. Apparently your dealer installed the arm with the Dennesen protractor, which is preset for the Baerwald geometry. That alignment is preferred by ’experts’ and obviously there’s no problem if you have a ’normal’ cartridge that can be adjusted in the headshell. But these fixed headshell types can never correctly aligned in the FR using Baerwald.

Do follow chakster’s advise and get yourself the Feickert tool. If you look up the specified P2S distance of the FR66 and set the ruler of the Feickert at this distance you can figure out if the top plate of the arm pod allows a position that corresponds to that distance. If so, than your FR7 and SPU cartridges will be correctly aligned to Stevenson.

Of course choosing this setting will require repositioning your other cartridges to Stevenson as well. But using the Feickert tool that’s a walk in the park. The experts will advise against this change as they religiously follow Baerwald and dismiss Stevenson. You can judge for yourself: if they are correct the performance of the Koetsu should take a dive after its alignment has been changed from Baerwald to Stevenson. Conversily, by now correctly aligned the performance of your FR7 and SPU’s might improve considerably. Either way, this may prove to be an interesting experiment!

Keep us informed!