What are the pro's & con's of "uni-pivot" tonearms?

[the_nines]

Something I've been meaning to ask, never got around to it.

'Till now ....

Anyone?

 

[gadget73]

I think the general pro is that there is a single bearing point, thus less friction if its made properly. Compare that to a standard gimbal setup and you've usually got 3 or 4 bearing points. 2 on the vertical axis and usually one on the horizontal. The unipivots sort of scare me though. They flop around like a wet noodle if touched. Always seems like its just going to snap off or something.

 

[Grbluen]

That's a big part of the reason I'll never sell my scout. The tonearm's a bit wobbly on descent, but I know I'll never worry about the tonearm bearings! That's a huge selling point.

 

[Multiplex]

I would think too, that having fewer bearings provides fewer sources of resonance and distortion that can muddy your audio.

 

[illini]

Unipivots are easier to manufacture (pro) but have less than desirable lateral stability (con).

 

[the_nines]

....but have less than desirable lateral stability (con).

Explanation please.

 

[jimreeves]

I admire Redboy's unipivot...
http://www.audiokarma.org/forums/showthread.php?t=256225

 

[the_nines]

So far ..... one 'con': "less than desirable lateral stability".

Still waiting for an explanation on that one.

Come on people.....

Pros ..... cons.

:scratch2:

 

[gadget73]

If you grab the end of a regular gimballed tonearm and twist it, it doesn't move, or at least it should not. A unipivot will roll a pretty fair amount back and forth. If you're playing warped records, it can make the arm rock back and forth when it hits the lump in the vinyl.

 

[elcoholic]

Seriously? Who can afford perfectly flat vinyl? Besides SQ, the second most important criteria of a great arm and cartridge combo is how well it can track less than perfect records.

 

[Ilikevinyl]

If you're playing warped records, it can make the arm rock back and forth when it hits the lump in the vinyl.

Some of the VPI arms offer fluid dampening. That's why you should use it. Handles warped records much better.

 

[the_nines]

If you grab the end of a regular gimballed tonearm and twist it, it doesn't move, or at least it should not.

Obviously, yes.

A unipivot will roll a pretty fair amount back and forth. If you're playing warped records, it can make the arm rock back and forth when it hits the lump in the vinyl.

So you're saying a regular "gimballed" tonearm can play warped records better than a uni-pivot. Yes?

IMO, a record has to be pretty warped to cause misery to any tonearm, gimballed or uni-pivot.

Why do uni-pivot tonearms exist (in the thousands of $$$) if they can't play a warped record.

How warped does a record have to be before it can't be read by a stylus with proper VTF & anti-skating? Gimballed or uni-pivot.

Again, just asking.

:scratch2:

 

[ETI_5000]

The JH Formula IV and its re-badged twins (or triplets!) from Polk and Sonus used silicon damping at the unipivot, as did Mayware’s copy, and it works well. I haven’t noticed it “rolling” from side to side when playing warped records, but that’s probably because of the effective damping.

One of the drawbacks of the JH, and probably many other unipivots, is that it needs to be balanced horizontally during setup. While that was also the case with some other tonearm designs, including many s-shaped tonearms, it wasn’t as critical with them, and could be ignored, something that can’t be done with unipivots, which need perfect horizontal balance, or they won’t be level. So the setup is a bit more fiddly.

 

[62sunbeam]

My Grace G704 is a Silicone damped uni-pivot tonearm and yes until it rests on the LP it can seem kind of precarious but interestingly once the TT is level and the arm is properly set up it settles right down and makes beautiful music.

It takes a steady hand and setup is finicky but not terribly so but once it is balanced on it's pivot and the the stylus it seems rock steady and tracks as well or better than any other arm I've had. I can't imagine that my SL-110 that I have it mounted on is any quieter than any of my other decks but the 704 on this deck is dead quiet. I really enjoy it.

It was funny because this is my first experience with a uni-pivot and right out of the box it wasn't properly balanced (azimuth is a matter of balance not hard adjustment) and it was a little catiwompus and sounded it. Once it was dialed in though it really came to life and is quite dynamic and musical with no mechanical interference.

Thanks

Eric

 

[the_nines]

So far:

Pro's: Easy to manufacture (how easy or hard this is, only the manufacturer knows)
Con's: Playing warped records


I can't say with certainty how easy (or hard) it was to manufacture the uni-pivot tonearm on my Clearaudio turntable, but I do know it has absolutely no issues playing warped records to within an acceptable degree. I don't play records that are warped to the point that the tonearm stands no chance of tracking, let's be realistic.

Anything else good or bad about uni-pivot tonearms?

 

[Jeff K]

According to Harry Weisfeld (VPI), the reason for using a gimbal on the Traveler instead of unipivot, was manufacturing cost. The more expensive VPI's all use unipivot.

 

[Frank Sol]

Somethings just are... No reason to ask why... The uni-pivot , at least from VPI , is A+ although it 'looks' strange at times while spinning a LP

Night & Day design difference from what the old Duals were

 

[ETI_5000]

So far:

Pro's: Easy to manufacture (how easy or hard this is, only the manufacturer knows)
Con's: Playing warped records; harder to set up (needs lateral balancing)

 

[luvvinvinyl]

I had an Ariston RD11S with a Magnapan UniTrac II on it. There was some Ortofon (542?) on it. I have some records with mild warping, even a few with minor pinchwarps. Nothing the Maggie wouldn't handle, but I don't have any 'potato chip' lps. Once the stylus hit the disc, it settled down nicely, and quite quickly so.

I should have kept that table.

 

[ejman]

So far:

Pro's: Easy to manufacture (how easy or hard this is, only the manufacturer knows)
Con's: Playing warped records


I can't say with certainty how easy (or hard) it was to manufacture the uni-pivot tonearm on my Clearaudio turntable, but I do know it has absolutely no issues playing warped records to within an acceptable degree. I don't play records that are warped to the point that the tonearm stands no chance of tracking, let's be realistic.

Anything else good or bad about uni-pivot tonearms?

I have one of the original unipivots , a Decca International and it has no more difficulty tracking warped records than my Rega RB300. It sounds very musical and it's only two additional fiddle points compared to a traditional arm is that one has to adjust the arms azimuth and determine amount of damping.