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Date: 6/11/2019

Product Review by : Steve Clarke (webmaster)

Riverstone Audio Record-Level Vertical Tracking Force Gauge - Silver

Price: ~ $29.99 around the web online.

 

Listed Specifications:

Capacity / Resolution: 

100G / .005g on the center platform.

20g / .005g on the lower platform cantilever extension.

Units: g / oz / T / gn / dwt / ozt / ct

Tare Range: Up to full capacity

Auto off: After 1 minute

Operating temp: 0 - 40C

Display: 5 digit LCD

Power: One AAA Alkaline battery (not included)

Dimensions: 92.5mm x 52mm x 13.5mm

 

Intro:

For those among us still playing records, and for those among us who may want to start playing records, there are some necessary tools that are to be considered as infrastructure.  Among the 'tools' one needs in order to support the hobby are a -dry- record dust brush, a stylus cleaner of one sort or another, a -wet- record cleaning system, and a VTF scale.  These aren't the only tools one needs, but they are to be considered essential.  The VTF scale (the subject of this review) is used to accurately set the vertical tracking force at the very tip of the diamond stylus that tracks the record groove.

 

Always, phono cartridges come to us with a recommended tracking force range.  For instance, on a vintage Shure M91E I see in their factory specification a recommended tracking force setting that ranges from as little as .75grams and as much as 1.50 grams.  If your setting goes outside of this range, negative and audible effects can be experienced...if not also to mention the potential for damage to your valuable record collection.  For this reason alone, everyone playing records needs an accurate VTF scale.

 

 Over the years there have been different types of VTF scales made available.  A popular one that was in common use back in the 1970's and still in use today is the Shure SFG-2.  It is a mechanical balance beam scale complete with a sliding weight.  A decade before the Shure scale, there was that Garrard SPG-3.  I have an example of both of the above.  In a pinch I will still use the Shure SFG-2.  But let us fast forward into the present.  Now we live in a digital age and we can find many different examples of digital VTF scales currently available to us.  Which brings us to the subject of this review; The Riverstone Audio Record-level Vertical Tracking Force Gauge.

This gauge (scale) features a 5 digit lcd display with a 100gram maximum capacity.  It will read in grams out to 3 decimal places and do so with a repeatable accuracy  to 0.005 grams.  What makes it interesting to me is it has been adapted to hold the stylus, with tonearm attached, at the same approximate level as it would be while playing a record.  In a couple of paragraphs I will give reason for this feature.  For now let us look at what comes in the kit for ~ $30.00 usd

 

Here's everything you get for $30.00 usd : Steel case for safe storage, two calibration weight standards (5 and 20gram), A leather case, the scale, a metal protective lift-off cover that fits over the center platform, the 'cantilevered extension arm' and the user manual.  It's a sharp looking kit and a nice presentation on the part of Riverstone Audio. (btw, save the manual, you'll want to have it)

 

Upon further examination what I see is a small compact digital scale with Riverstone Audio labels on it.  Nicely done labels!  I see the record level adapter lever, which they call a 'cantilevered extension arm', that clips over the center platform, getting hooked underneath on either side. The folded sheet metal extension has 180 hook on its narrow end and catches into a slot just underneath the platform, left side. On the other end of the cantilever,  with the 'record level measuring platform' there fits a screw in a slotted hole with an oblong metal tab/clip at its bottom.  Turn the knurled head up topside and the clip/tab rotates with it connectedly with the ultimate goal being to stick that oblong tab length-wise into a slot just under the above center platform.

 

Like all VTF scales,  it measures the vertical tracking force of your arm/cartridge,  except that it measures tracking force at record level to increase accuracy of the setting.  

 

But why Record Level? 

I can think of two reasons;  The first and most common reason is that if you were to set VTF on your tonearm / cartridge at, say, 3/4" higher than at record level, the force you set would not be exactly the same as at actual record level.   What we seek here is accuracy.  The second is a somewhat specialized reason. I happen to own a Thorens TD124 turntable that has the heavy iron flywheel beneath that propels above it the upper light clutch-operated aluminum platter.  The concern is that some phono cartridges (particularly moving coil cartridges) have magnets within them strong enough to become attracted to that iron flywheel beneath.  Think of a phono cartridge trying to pull itself down into that spinning iron less than 1/2 inch beneath it.  This would result in a setting much heavier than you thought had you set vtf off to the side, like many do, and not directly over the iron.  However, it is possible to compensate for this magnetic force by setting vtf --at record level-- directly above that iron flywheel.. The closer that cartridge is to the arm, the more it gets pulled... Anyway,  when you check the vtf reading above the flywheel and then off to the side and away from the iron, you get two different reads.  Therein lies the proof in that pudding.  By setting vtf directly over the iron, and at record level, I have compensated for the magnetic pull of your typical low output moving coil phono cartridge.  And I do use that type of cartridge.  This is why I am interested in using a record level vtf gage.  And perhaps you might be as well....especially if you have a TD124.

 

Here are two example photos of the setting on the TD124  The cartridge in use is a Shelter 501-II.

Read over iron.

 

Read away from the iron.

 

Anyway you do the math to see how much force is in that pull when over the iron.  The point is that I now know what my 'actual' VTF is when playing over the iron platter.  It is absolutely essential for those using this turntable.

 

Something useful, I hope:

Just so you know up front, you'll spend some time calibrating this scale.  It comes calibrated for the 20g std.  But we really need it set to the 5g std.  We're measuring in the range of 0.5g to 4.0g. when playing Lps.  So I study the instruction manual to figure out how to change the calibration.  It seems there are 5 steps described to calibrate this scale.  But it wasn't that hard to follow.  In case it might be useful, below is my perceived version of the procedure.

 

Calibration procedure: Firstly, this scale comes factory calibrated to 20grams.  We need to change calibration to 5 grams. Here's the procedure:

1: press power button.  Wait until 0.000 is displayed.  Verify units by noting the symbol lit in the upper left corner of the display.  If it does not show the letter "g" lighted, press the units button to cycle through the seven available units until it the letter g lights.

2: Press and hold the power button until the display disappears, continue holding until "0" shows on the screen, then release.

3: "0" will be followed by a blinking number value (likely 20.000)  That indicates the current calibration value.  To change that value press and release the unit button repeatedly until you see the number 5.000. The blinking continues. but don't stop now, we're not done.

4: within 5-6 seconds place a 5gram weight at the center platform or on the white pad of the extension (whichever is to be used) Wait until the 5.000 stops blinking, then the gauge will return to normal measuring mode and the display will show within .005g of 5.000g.

5: Remove the calibration weight and turn off the gage.  The vtf scale is now calibrated and ready to use for checking vtf.

Btw, I've worked through the above procedure and can report that with the scale calibrated to the 5.000 gram standard, it did read out 4.995g.  That makes sense when you consider that in that third decimal , scale resolution is to the nearest .005 g.

 

Stuff you might want to know:

And then there is the way that "extension" gets fixed into position. A  little oblong tab at the bottom of the lock screw needs to rotate into position roughly angled into the slot it must hook.  In practice you soon realize that the special screw and oblong tab at its other end are locked in rotation to one another and that you can aim the tab quite easily by turning the knurled head between your thumb and index.  That said, you might find it simpler to deal with this in bright lighting....Perhaps working under a desk lamp will do.

 

hint; click on thumbnail to view image full size.

The above image, scanned from the manual, demonstrates the catch.

 

Two more looks at the Locking Screw:

Locktab screw detail_2.jpg (512756 bytes) Close up detail of the assembly.

 

Locktab screw detail.jpg (400101 bytes)  Detail of the lock screw. Custom machining here.

 

hint; click on thumbnail to view image full size.

Observations, thoughts and summary:

Once familiar with the setting up of this instrument, actual use is convenient and easy.  At $30 bucks plus ship, you can't go wrong.

 

 

Misc. scans from the manual.

manscan_Figure 2 A-D detail.jpg (575420 bytes) installing the cantilever extension

manual scan_calibration.jpg (456442 bytes) Calibration (you'll need it)

manual scan_Figure 1.jpg (502522 bytes) What comes with it.

There's more to it but you get a manual if you buy one.

Recommended

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