VPI Classic 3 + 3D Tonearm SRA Adjustment issue

Ok. It was good timing that VPI just started a support forum on their own website last week. I posted the issue there and they responded quickly. It turns out VPI's unipivot arms' female bearing socket height can be adjusted with a hex wrench. It adjusts quite a bit. I had to play with this some because if raised too much this way the arm's lift will not reach the tonearm pipe anymore, rendering it useless. However I was able to reach a good overall compromise position that did allow to set the SRA at my desired angle and lock the platform in place to the guiding post--and operate the lift. Thanks to all who helped.

Isaacrivera.....actualaly, your arm is WAY higher in the back than is mine. The arm is severely tapered... the bottom of my arm looks to be horizontal to the record itself. I have a much heavier rear counterweight...(the Benz cartridge is very heavy and needs the heavy rear counterweight.

Isaacrivera, from your photo your tonearm is not as high on the pivot end as I had imagined. I found for both the JMW 10.5i and 3D arms that the CounterIntuitive device made adjusting more difficult, so I did without them on both arms. Regarding the counterweight, mine is sort of in between the pivot bearing and the end of the tonearm. I don't want to switch weights at this point as I'm happy with where things are set. I have the fine adjustment weight attached to the main counterweight which is very useful for dialing VTF in with more precision.

Thanks Brf, Stringreen...

Stringreen, I have read your thread on the 10in 3D arm and it appears that the issues got resolved around last month by VPI. I got my arm back in May. You can see a pic of it here ( http://www.vinylengine.com/turntable_forum/download/file.php?id=9493&mode=view ).

Does this look like the right combo to you? I am wondering if I need a heavier counterweight to move it closer to the bearing and also whether I got the right kind of counterweight at all, because mine is hard to do fine adjustments with. It feels like the thing is lined with rubber inside it resists sliding on the arm tail a lot.

Heidmuse knows what he's talking about. I have a rim drive/3D arm and started with the arm as close to level as I could get......I could VERY clearly hear the sound getting better as I raised the back end....however, it is not that high at all. I am using a Benz LPS...and believe that every cartridge is a bit different, and am confident that Heidmuse is right for his cartridge. Let your own ears be your guide...

You should also consider purchasing a Mint LP cartridge protractor specifically designed for the VPI arm. I found that it gave superior results when compared to the VPI supplied alignment gauge.

Thanks Dougdeacon, the VTF methodology you describe sounds appropriate for figuring the cartridge's actual range. And VTF seems like the base upon which all other settings are built on. So I will go back to the drawing board next weekend. I may also get a more accurate scale. Mine is the one supplied by VPI and, though it does not change when I approach the cart to the scale, I sometimes have to weigh several times and use the most repeated value, there is variation.

Isaacrivera,

Good job deciding to fine tune your own setup. It's the only way to optimize the performance of any rig. Here's a thought. Bear with me, since you probably think you've covered this.

If VTF is too high it will compress the cantilever to a more horizontal position than the designer intended. Compensating for this to get SRA back to something akin to normal would require raising the arm to well above parallel, just as you've described.

Every cartridge is unique and any sensitive cartridge (including the 20X2-L) also changes with the weather. If it's been hot and/or humid where you live, this will cause the cartridge (any cartridge) to need less VTF to center the cantilever between the magnets and play its best.

You've checked VTF with a scale. Make sure you're weighing at record height and that the scale is not magnetically attracting the cartridge. Ignoring either of these can produce inaccurate VTF readings.

Now learn how to go beyond the scale and fine tune VTF with your ears.

1. Start by setting VTF to the bottom end of the recommended range. Return your tonearm (or the top of the cartridge body) to level.

2. Set anti-skate, if you use it, to zero.

3. Play a record that's tough to track, particularly on inner grooves. Listen for faint mistracking (a brief "fzzz" or buzzing sound that occurs in synch with dynamic peaks in the music).

4. If you don't hear hear that, nudge VTF downwards in tiny amounts until you do. We'll call this the "mis-tracking point" (for this particular cartridge, on this particular record, on this particular day).

5. The mis-tracking point is a good baseline for fine-tuning VTF with any sensitive cartridge. Measure it with your scale so you have an idea wherre it tends to be.

6. Of course you don't want to play valuable LPs with the stylus on the edge of (or over the edge of) mistracking. So... nudge VTF upwards in *tiny* (like .001g) increments. Listen closely...

The first thing you should hear is the mistracking going away. As you continue to inch VTF upward you may hear dynamics strengthen and/or bass tones becoming stronger. This is good. Keep inching VTF upward.

At some point you'll hear HF's and/or micro-dynamics start getting smothered. Let's call this the "excessive VTF threshold". Stop increasing VTF and measure it.

The range between the mis-tracking point and the excessive VTF threshold is the range this cartridge likes to play. Back off VTF slightly and you'll be in the heart of that range, able to track all normal records safely with maximum sonic performance.

Now, and only now, begin playing with SRA adjustment. Use your microscope if you feel you need to justify what it cost. ;-) I used to do that but now I just use my ears. With practice it's much faster than fussing with microscopes and lights. I can dial in SRA on any rig, even one I've not heard before, in just a few minutes.

The same with azimuth by the way. Levelling with a pencil lead or rod is a good start. Making the stylus appear vertical when viewed from the front while playing is a better one. Fine tuning by ear from there, in *very* tiny increments will often produce further sonic improvements.

Hope this is helpful as you build your independence as a vinyl tweaker!

Hi Hiendmuse, thanks for your thoughts. I had the arm parallel for 4 months. The resulting high tail from the microscopic adjustment actually sounds much better in this system. I have some old 6-eye Columbia records that always sounded out of register and I though that's how mid-50's Columbia records sounded. Violins in particular sounded high-pitched and textureless. Boy was I wrong! Not only do they sound in good pitch and nuanced. There's a whole orchestra of properly-pitched instruments too! Bass has gained weight and depth. They problem with trying to set SRA via VTA is that it assumes everything in between is just perfect. The arm has no variation and the cartridge is perfect. Microscopy bypasses those potential areas of variation. In the end the adjustment changed a good 15mm upwards. An SRA setting change that big can't be adjusted by ear. The farther you are from the "correct" spot, the less meaningful small changes sound. But from one degree off to the "correct" spot, the change is dramatic. So a 15mm difference is almost impossible to get to by ear if you change a few mm at a time you won't hear a difference.

I have a Super Scoutmaster Ref. rim drive and recently installed a 3D tonearm to replace the JMW 10.5i arm. I use a Lyra Titan-i cartridge. I have found that both arms sound best when parallel to the platter. I use the Classic platter. I recall reading a post by Stringreen who said he keeps the pivot end up high of his 3D arm to achieve between 91 to 92 SRA. VPI recommends keeping the arm parallel and is a good starting point.