Decided to try a SPU cartridge

there is one arm manufacturer that the SPU's will work with that flies in the face of this rule, this being the Viv Lab's Rigid Floats.

Wow, you’ve definitely got my attention! This is exactly what I was planning on trying as soon as Ortofon had SPU Classic GM E MKII inventory again. With the headshell collet of the ViV Labs, I would assume a std (non 1/2”) SPU would also be ideal. 

From what I am hearing from users, seems like offset angle/zenith/HTA may not be the end all. Lateral stability in the generator from an absence of antiskating compensation makes for an experience normally associated with linear tangential trackers. May be a function of their ferrofluid damping? Seems like an interesting topic for discussion. Looking forward to investigating soon.

@dover 

Thanks for the info.  Trying to determine which SUT to purchase - seems like a daunting task that I'll likely try at a later time.  I have been eyeballing a Zesto Audio Andros Allasso SUT on sale now used for $2k.

@alan60 

Wow, thanks.  After very much deliberation, I was targeting a Kuzma 4point as the next tonearm purchase (in addition to a SPU tonearm) and was just debating on which tonearm wire so I reached out to Fremer.  You now report that the ViV is better for the SPU.  I have a Lyra Edna and a Koetsu Redwood Signature Platinum, do you believe that the Viv is superior or just different than the 4point?

FYI - it is reported that the Glanz tonearm may be the best for SPUs.  It runs ~$8k

I don't think HTA = zenith.  The term HTA is relatively unfamiliar to me but as defined here it is the same as "Tracking Angle Error", the angle by which the cantilever deviates from tangency to the groove, TAE is the term I usually use.  TAE or HTA is changing as the stylus traces the LP and the tonearm rotates on its bearing.  Zenith is relatively constant, if the reference point is the LP surface.  I It changes as the TAE, if the reference is the orientation of the stylus in the groove, but it is not identical to TAE/HTA.  I am not planting a flag here, but it is a good idea if we all speak the same language.  I certainly can be wrong.

This whole HTA discussion highlights that if you want accurate alignment, you should only buy

- cartridges with conical/spherical tips

or

- cartridges that have a nude mounted square shank diamond and the cantilever has been laser cut.

If you are spending $5-10k on a cartridge, spend another $100 to have it independently inspected by a cartridge retipper. I have seen several $5-10k cartridges with styli mounted askew/cantilevers mounted incorrectly ( rotated ).

I'm planning to have all my cartridges reviewed by WAM Engineering - I'm of the belief that because of cantilever and stylus manufacturing alignment inconsistencies, the best way to align a cartridge is to get the stylus angle correct (vs aligning by cartridge body and/or cantilever).  IIRC. the resulting WAM reports will tell me how much the stylus if off perfect alignment so I can compensate by adjusting the cartridge body.  I'm somewhat concerned that some SPU tonearms may not allow zenith adjustment if needed.