SME iV.Vi or SME V for SME 20 turntable?

Jaytea: I do not and never have had an SME 20/2 turntable, only a VPI HW-19 III ; however, I have had both the SME V and SME IV.Vi tonearms. In fact, the IV.Vi is still my current arm. I would listen to the advice from the people at Sumiko. The simplest way to explain the difference between the two arms is to say the IV.Vi has the same nice, reassuring sound as the V, but gives a little more [needed} top end extension. It is a better sounding arm from top to bottom, and cheaper too. There is one other difference, though, in terms of what is offered with each arm. With the V comes the damping mechanism, which isn't supplied automatically with the IV.Vi, but you can buy it as an option. My comments about the sound of the IV.Vi stand, even without the damping mechanism, which I never purchased. Hope this gives you a clear direction. Best of luck.

fwiw, the damping mechanism came with 20/2a iv.vi i bought a few months ago. my dealer thought it was an option, but it came standard.

my dealer, whose a long time sme user himself, recommended i get the cardas reference gold cable. it all sounds great, but i haven't tied other cables.

The damping trough IS an option if you buy the arm separately. However, I dont think the IV.Vi is sonically any different than an SME V -- it's an identical mechanism -- EXCEPT for two things: the internal wiring, and the aforementioned damping trough.

The IV.Vi was designed with MC cartridges in mind, which due to their usually low compliance, don't really require damping.

The internal wiring is actually a coated ribbon instead of the vdH 150M used in the V arm. Initially, SME used Magnan for their OEM ribbon, but now makes their own. According to SME, the ribbon does two things: offers less resistance to movement of the bearings, and less electrical resistance to the tiny signal produced by MC cartridges. This supposedly allows MC cartridges to "be all they can be".

One disadvantage, if you don't get the optional damping trough, is that you also don't get the tonearm height adjustment mechanism. SME IV and V arms are difficult enough to height adjust, so not having this feature is a real PITA, IMO ;--)
.

Nsgarch is correct. I completely forgot about that tonearm height adjustment mechanism. And the arm IS somewhat of a pain in the butt to adjust, as I've realized when dealing with long play records of varying degrees of thickness. However, I do not agree with his contention that the IV.Vi and V are sonically the same. To my ears at least (As mentioned in my first response, I have owned both arms.), the IV.Vi has slightly more top end information, and perhaps just a tad less fullness in the bass. This combination of factors produces what I hear as more of an even balance throughout the sound spectrum. All said, however, both arms are top notch, and are my favorites among all arms I have owned, including the Zeta, an earlier version of the Triplanar, the Alphason, and several of Harry Weisfeld's VPI tonearms.

Opus, both arms are indeed physically identical in terms of parts, materials, etc. So if you are hearing a difference, it has to be due to the internal wiring differences. And it stands to reason that the wiring should produce sonic differences, especially with the very low output MC cartriges (.3 mV +/-), otherwise, why would SME bother making this special version?
.