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TriPlanar Tips

The manual that comes with the TriPlanar Mk VII tonearm is fairly complete, but there are a few things I’ve learned only by living with the arm. Note: I do not know which if any of these would apply to previous versions of the arm. My only experience is with the Mk VII.

1. NEVER raise the cueing lever while the arm is locked in the arm rest. This pressures the damping cylinder and could cause a silicone leak. For this reason and also for safety, whenever the arm is in the arm rest the cueing lever should be DOWN. This is backwards from most arms and takes some getting used to.

2. If your Tri-Planar doesn't cue straight down there's a quick fix, which may be included on some new arms. The problem is insufficient friction between the arm tube and the hard rubber cueing support bar. Just glue a bit of thin sandpaper to the underside of the arm tube. Make it big enough and position it so it hits the cueing support bar at all points across the arm’s arc. (Note: after doing this you will need to adjust the cueing height, see Tip #3.)

3. When adjusting cueing height (instructions are in the manual) always do so with the arm in the UP position. This adjustment is VERY touchy, since the cueing support bar is so close to the pivot. Be patient and be careful of your cartridge. (Note: after doing this you may need to adjust the anti-skate initiation point, see Tip #4.)

Chris Brady of Teres told me of a way to improve cueing even more by re-shaping the cueing support. Moving the cueing support point farther from the pivot improves its mechanical advantage and makes the cueing height and speed adjustments less touchy. This mod is easier than it sounds and requires only a length of coat hanger (!), but I don’t have pix and haven’t yet done it myself.

4. Changing the cueing height affects the point where anti-skate kicks in. (Yes, it's weird.) Once cueing height is satisfactory, adjust the short pin that sticks out of the front of the cueing frame. That pin controls where the anti-skate dogleg first engages the knot on the string.

5. The Tri-Planar comes with three counterweight donuts of differing masses. Many cartridges can be balanced using either of two. The arm usually tracks best with the heaviest donut that will work, mounted closer to the pivot. Of course this also reduces effective mass, which may or may not be sonically desirable depending on the cartridge. It also leaves more room for Tip #6.

6. For fine VTF adjustments don’t futz with the counterweight, there’s an easier way. Set the counterweight for the highest VTF you think you’ll need (ie, close to the pivot). Pick up some 1/4" I.D. O-rings from Home Depot. To reduce VTF a bit just slip an O-ring or two on the end stub. Thin O-rings reduce VTF by .01-.02g, thick ones by .04-.05g. Quick, cheap, effective. (For safety, always lock the arm down while adding or removing O-rings.)

7. When adjusting VTA, always bring the pointer to the setting you want by turning it counter-clockwise at least ¼ of a turn. This brings the arm UP to the spot you've selected, which takes up the slop in the threads. You can easily feel this happening.

Hope someone finds these useful. If you know any more, please bring ‘em on!
dougdeacon
paperw8
165 posts
 

Tapping on a Rega to find resonance points is one thing, tapping on a Triplanar is plain foolish and will not reveal the differences in nuance that these tips address. The vibrations created at the cartridge are entirely different from the vibrations you created by tapping on your arm. Your empirical observations are completely irrelevant to what happens in the cart/arm during playback. And let's not forget that the particular cart in use will have an impact on the vibrations the arm sees.
Heretofore, people have just thrown around the term "resonance" without saying exactly what they were talking about. It appears that you are citing a specific resonance: namely, the resonance in the cantilever of the cartridge. This is something that I can work with.

From what I understand, concern about cantilever resonance is a legitimate concern. However, the way that you address that concern is to know what you are doing before you buy the cartridge. For example, it is not a true statement that the trough in the Triplanar is "vestigal"; if you use a low compliance cartridge with the Triplanar you can have problems with resonances in the cantilever. That was why the trough was put there - for use with low compliance cartridges; and there are companies (like Clearaudio) who still make low compliance cartridges. The thing to do, then, is to look at the specifications for the cartridge to determine where the resonance is likely to be if you install it on a Triplanar tonearm. As I understand it, you typically want the resonant frequency to fall in the 8-12 Hz range.

Now, if there are other sources of resonances to which some here are referring, where the source or potential cause is not articulated, then I can't work with that. But what I do know, is that it appears to me that there is a fair amount of effort involved in removing the trough from the Triplanar. I don't know why I should undertake that effort other than for the fact that I read some comments from people who proclaim that it will make a difference and that, somehow, if I can't tell the difference then the fault lies in my hearing or in my system. I make no personal statement about anyone making such assertions, but the way that I think about things, it's hard for me to work with these kinds of claims if I don't understand the underlying physical phenomenon that I am trying to address. My training is in electrical engineering and not in the arts, so I think about this stuff differently.
jb0194
476 posts
 
Hi Thom,

Is the "-3dB @ 3Hz" primarily designed into the turntable power supply?

I own an nicely working old radio station Technics SP-10 MKIIA and would like to know if/how I can optimize my table in this regard.

FWIW, I have a Tri-planar arm en route and have found this thread most helpful.

John

Thank you.
jfrech's avatar
jfrech
1,816 posts
 
Hi Paperw8,

"But what I do know, is that it appears to me that there is a fair amount of effort involved in removing the trough from the Triplanar."

It took me 1 minute to remove the trough. Simple, easy 2 small screws. 30 seconds with the needle in the grove and you won't look back.

Of course my table allows me pretty easy access to the bottom of the arm. Other's may not have this. Such as I have a friend who was about to remove his arm, instead we took a pair of vice grips to a $1.00 jewelers screw driver and put a 90 degree angle in on the tool. So for him, 1 min with the vice grips, 1 min with the (now 90 degree bend) screw driver. Lifetime of better sound...

If you can give this a try, maybe via this bent screw drive method, we'd all be curious to your thoughts afterwards...Thanks
paperw8
165 posts
 
Here is an equation that I found to estimate the resonant frequency of the cartridge cantilever:

rf-c=159/sqrt((eff_mass-t+mass-c+mass-f)*(compliance-c))

rf-c: resonant frequency of cartridge cantilever (Hz);
eff_mass-t: effective mass of tonearm (g) (11g for Triplanar);
mass-c: mass of cartridge (g);
mass-f: mass of fasteners to attach cartridge to tonearm (g) (I use 0.5g as a guess);
compliance-c: compliance of cartridge (10-6 cm/dyne).

As an example, I have a Lyra Delos cartridge so for me:
mass-c: 7.3g;
compliance-c: 12;

so I end up with rf-c=10.6 Hz.

I treat this as an estimate, but it is well within the 8-12 Hz range.
thom_at_galibier_design's avatar
thom_at_galibier_design
729 posts
 
Hi JB0194,

While the example I gave was for power amplifiers, the same does indeed hold true for any conventional (non-digital) power supply design.

Since my turntables are batterey driven, I haven't had to chase down power supply filter issues. I'm sorry that I can't point you toward a theoretically optimum number.

Cheers,
Thom @ Galibier
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