I’m running an SPU Century on a Korf SF9R, which has an effective mass of 18g without headshell and a stainless steel arm wand but it’s not optimised for SPUs. It comes with its own headshell and an overhang gauge for 50mm whereas the corresponding distance for a G type pickup is 52mm, however mounting the arm 2mm further from the spindle at 216mm gives as close to Stevenson as makes no odds and closer than Korf’s chosen alignment according to vinyl engine’s calculator. I also have an SPU Royal N which mounted in the Korf headshell at 52mm gives a bit more dynamics and impact but the Century seems to relate the different strands of music to each other more meaningfully. I love both but the Century has become my first choice.
There’s one little niggle however. The fit between the Century and the Korf collar allows for a bit of movement, not a lot but enough to affect azimuth, it will hold with the pressure of the contacts but not if I use the finger lift, so I’ve removed it and move the arm by its wand. The Korf headshell, which has two pins, is nice and secure and I initially thought the Century’s single pin must be narrower but my micrometer tells me they’re the same diameter at 0.995mm, the Century’s pin is a bit longer and I remember reading a review of the SPU 1s by Art Dudley (https://www.stereophile.com/content/listening-168-ortofon-spu-1s-phono-cartridge) who found the pin too long for his EMT tonearm and filed it down after wrapping the pickup to keep the swarf out. Could this be the issue here? I’m rather reluctant to start butchering a Century to find out, maybe that’s my excuse to try an SPU 1S.
I sent the above to Alexey Korf who replied:
“Hello Chris,
Thank you for your email!
When you have 2 pins they are never exactly aligned with each other. As a result, you have some tension taking up the slack between the slots and the pins. This is why 2-pin headshells are more stable in azimuth. With a 1-pin headshell, there is always some play. Yours isn't the worst I have seen, not even close! It's just a limitation of this type of connector itself.
If the connection of the headshell itself is not stable and there's a bit of a rattle, that's a different thing altogether. There are many reasons why it can happen--the diameter of the cylindrical boss on the headshell may be too small, or the finish on the flange might be such that the perfect connection is not possible. In this case, I would try different elastic washers between the headshell and the connector. Or, as you said, the pin might be protruding too much. But the Korf tonearm has some safety distance there, and with pins up to 2 mm long there should not be any problems.
Hope that was helpful!
Kind regards,
Alexey”
The SPU Century’s pin is 1.8mm long according to my vernier so shouldn’t be the issue here, the Korf’s upper of its pins two is 1.4mm, the lower looks the same length.
There’s one little niggle however. The fit between the Century and the Korf collar allows for a bit of movement, not a lot but enough to affect azimuth, it will hold with the pressure of the contacts but not if I use the finger lift, so I’ve removed it and move the arm by its wand. The Korf headshell, which has two pins, is nice and secure and I initially thought the Century’s single pin must be narrower but my micrometer tells me they’re the same diameter at 0.995mm, the Century’s pin is a bit longer and I remember reading a review of the SPU 1s by Art Dudley (https://www.stereophile.com/content/listening-168-ortofon-spu-1s-phono-cartridge) who found the pin too long for his EMT tonearm and filed it down after wrapping the pickup to keep the swarf out. Could this be the issue here? I’m rather reluctant to start butchering a Century to find out, maybe that’s my excuse to try an SPU 1S.
I sent the above to Alexey Korf who replied:
“Hello Chris,
Thank you for your email!
When you have 2 pins they are never exactly aligned with each other. As a result, you have some tension taking up the slack between the slots and the pins. This is why 2-pin headshells are more stable in azimuth. With a 1-pin headshell, there is always some play. Yours isn't the worst I have seen, not even close! It's just a limitation of this type of connector itself.
If the connection of the headshell itself is not stable and there's a bit of a rattle, that's a different thing altogether. There are many reasons why it can happen--the diameter of the cylindrical boss on the headshell may be too small, or the finish on the flange might be such that the perfect connection is not possible. In this case, I would try different elastic washers between the headshell and the connector. Or, as you said, the pin might be protruding too much. But the Korf tonearm has some safety distance there, and with pins up to 2 mm long there should not be any problems.
Hope that was helpful!
Kind regards,
Alexey”
The SPU Century’s pin is 1.8mm long according to my vernier so shouldn’t be the issue here, the Korf’s upper of its pins two is 1.4mm, the lower looks the same length.
