JMW 10.5 arm / v.d.H. Frog set-up parameters

I use a van den Hul Frog cartridge mounted in a V.P.I. JMW 10.5 arm on a standard Aries turntable, and seek advice about set-up parameters, and in particular, about V.T.A. set-up.

My cartridge was installed by an installer experienced with cartridge set-up, and my turntable has been carefully leveled as measured from the platter surface. I am not much of a tweeker and have resisted the temptation to mess around with any of the set-up parameters since the cartridge was installed over two years ago, but, as the vertical tracking angle can be varied easily with the JMW arm and then returned to its initial setting, I spent the last few nights trying different settings. The installer had the pivot-end up somewhat, the arm tube sloping down slightly toward the cartridge. I brought the arm down to where it is level with the platter, which took +/- four revolutions of the VTA tower and constituted nearly a 1/4" drop in arm height at the pivot (as estimated from vertical movement of the arm base stabilizer post, which I had suspended underneath the arm cradle for purposes of making VTA adjustments).

Moving the arm up and down within this range brought surprisingly subtle changes. Compared to the original arm height, having the arm level with the platter seems to produce a very slightly fuller sound, with very slightly less well-defined images and a somewhat more diffuse center image. Raising the arm back up to the position it was set at by the installer restores the imaging and center image, and seems to take away just a touch of body compared to the level position. I ended up returning the arm to the original, installer-set, position.

I also removed some silicone from the pivot well and now have a silicone level that is +/- 1/4th to 1/3rd full (3/4ths full is the recommended starting point). This seems to have made a more audible difference, yielding a somewhat more lithe presentation which is pleasing to me. As for effects of the weather on the silicone levels, the ambient temperature in my listening room is +/- 70 F. (21 C.)

Nothing I did to the arm over the weekend radically altered the sound or audibly increased distortion.

I know that azimuth and VTA are said to be crucial to proper performance with the v.d.H. cartridges due to the line-contact shape of the stylus (the smaller "v" represented by the shape of the stylus has to be positioned just right to fit and sit properly within the larger "V" represented by the groove). I also believe I have read that, generally speaking, and assuming a cartridge properly mounted in the headshell, a tonearm that inclines toward the cartridge tends to accentuate high frequencies, while an arm that is down at the pivot end tends to accentuate bass (these arm angles, respectively, causing the stylus to lean forward or to recline in the groove as compared to sitting perfectly upright), and that, level to the platter is generally considered the best starting point. I know that actual VTA varies with every LP depending upon disc thickness and several other parameters.

Are there any owners of VPI arms with v.d.H cartridges out there, or people generally savvy to turntables, who have experimented at length with set-up parameters that have advice to share? Any general or specific advice would be welcome. I am reluctant to undo the expert work of the installer who installed the cartridge (for example, I would definitely not try to change azimuth), but wonder whether any of you have found that doing any particular things were really good (or really bad).

I am passing the content of this query to George Stanwick and to Sheila Weisfeld whom, I admit, I have never previously asked about this subject (mostly due to the alleged sensitivity of v.d.H cartridges to set-up, I have deferred to the installer's set-up since the cartridge was installed).

Many thanks in advance for responses.
Raquel, I also have the vdH Frog on a VPI - JMW 10.5 arm. And I enjoy them immensely.

My experience with the VTA is similar to yours; I prefer the arm somewhat raised at the rear (which is also van den Hul's advice - don't fail to visit his website). But I don't find it all that sensitive - for me it generally takes about a half-rotation of the dial to hear any change at all.

However, much more sensitive than VTA is the azimuth. I can detect extremely small adjustments. When the azimuth is not optimal there is a roughness in the sound. Don't be afraid to experiment. Although you can't adjust azimuth 'on the fly' the way you can dial the VTA, it's not at all difficult - just a matter of securing your tonearm and then turning the wheel at the base of of the arm, clockwise or counterclockwise. (Again though, very small adjustments will matter - try a degree or two at a time. For me, the best position is in fact just about 'dead center.') If you don't like what you hear, you can simply return it to its original position, as you did with your VTA. The JMW 10.5 is a wonderful tonearm for these easy, quick adjustments, so take advantage of them!

As to tracking force, I find that VPI's recommendation to go to the high end of the cartridge's range is right. I fine-tune by ear; but I just checked for you, using a scale, and my Frog is weighing in at 1.87 g.
Raquel...I have a question. When you said "which took +/- four revolutions of the VTA tower" did you mean 360 degree turns? Wow lots of turns. I never went that far with mine ( I also have the 10.5). Maybe I haven't locked in yet? ALSO...where is the VTA release screw? Must you always tighten it after you set the VTA? Help folks....TWL, Tks all!!!!
Dear Rwd:

Yes, four 360 degree turns.

The release screw is near the top of the tower and bored into the part of the tower that you hold for purposes of turning the threaded tower assembly.

Incidentally, there may be disparate opinions regarding set-up from van den Hul on the one hand, and V.P.I. on the other. The van den Hul site says, very generally with respect to cartridge V.T.A.:

“112 Q: Arm manufacturers always advice [sic] to keep the arm parallel to the record during playing. Is this right ?

A: To my experience it’s not right. What I learned was that in the playing position the arm must always be somewhat higher at its rear end (the counterweight end). A 9 to 9.5 inch arm around 7 - 9 mm higher. This improves the resolution a lot. Works with any arm and any cartridge. What you have to keep in mind is that each record is different. So fine-tuning the spatial resolution is slightly different per record. This can be fine-tuned by changing the distance between the arm bearing and the mounting board.
One millimetre up or down can be enough. But the average of 7 - 9 mm up works always in your advantage.”

This comes from

The good folks at V.P.I. e-mailed last night to say:

“From our own usage of this combination and from overall industry designs we have found that the Frog usually sounds the best with the back down slightly and the tracking weight around 1.5 grams.  The biggest changes in sound when doing VTA happen when you are in the sweet spot.  I do not think you are their [sic].  Try lowering the arm so that the back is slightly below level and rebalance your system for this setup.

I am waiting to hear back from van den Hul's U.S. distributor, George Stanwick, who I hope will have comments about the specific combination of 10.5 arm and Frog.

To be continued.
Thank you!