1 REF USER-GUIDE ***********************
1.1 TABLE OF CONTENTS =======================
Table of Contents ^^^^^^^^^^^^^^^^^
* 1 REF USER-GUIDE
* 1.1 TABLE OF CONTENTS
* 1.2 OVERVIEW
* 1.3 PRODUCTS INCLUDED IN THE KIT
* 1.3.1 DUAL AXIS BLADE [FIG1]
* 1.3.2 FRONT/BACK AXIS BLADE [FIG2]
* 1.3.3 LEFT/RIGHT AXIS BLADE [FIG3]
* 1.3.4 FEELER GAUGES [FIG4]
* 1.3.5 STACKING SPACERS & SCREWS [FIG5]
* 1.3.6 35 mm RULER [FIG6]
* 1.4 INTRODUCTION
* 1.5 PROCEDURE TO FOLLOW [PRINCIPLE USE]
* 1.6 ADDITIONAL USES
* 1.6.1 ADJUSTING HEADSHELL ANGLE FOR IDEAL SRA & VTA
* 1.6.2 MEASURE THE IDEAL AZIMUTH ANGLE
* 1.6.3 MOVE CARTRIDGE TO ANOTHER TONEARM
* 1.7 GENERAL NOTES
* 1.8 APPENDIX
1.2 OVERVIEW ==============
These instructions will inform you on the proper usage of the Reference.
The Reference "Blades" are designed to position your tonearm’s headshell so that it is perfectly parallel to the record surface on two axes. This has many benefits, and is especially useful as a "baseline starting point for calibration.
* If your cartridge was built to perfection, this one alignment process with the Reference (alone) would be enough to ensure your cartridge will play at its ideal SRA, VTA and azimuth. Unfortunately, Engineering has empirically determined that this is almost never the case. Microscopy and electrical measurements are absolutely necessary for optimizing the performance of your cartridge.
An additional use for the Reference "Blades" (particularity when following a microscopic inspection of your stylus wherein your cartridge’s native SRA & VTA is determined) is to use them to implement this empirically measured [Ideal] SRA/VTA alignment.
* "Native" SRA & VTA is determined when the top surface of cartridge is perfectly level to the record, nominal VTF is applied, a photograph taken on an axis shows a stylus mounting that is "perfectly perpendicular" to the horizontal alignment of the cantilever, after proper geometric measurements for SRA & VTA are taken.
Also following an electronic measurement for the ideal azimuth, one can also use the Reference Blades to find and record the optimal left/right headshell angle.
* This process offers a way to avoid ever having to measure azimuth again for this specific cartridge, regardless of how often it is moved to other tonearms
Note:
Rolling uni-pivots (as opposed to uni-pivots designed with a rigid stabilizing mechanism) that allow the pivot housing to rock atop the uni-pivot in a clockwise/counterclockwise manner tend to be "problematic" to use with the Reference -- please note that the Reference can only **accurately** measure azimuth angles with fixed bearing tonearms and/or with uni-pivots constructed with a rigid stabilizing mechanism.
1.3 PRODUCTS INCLUDED IN THE KIT ==================================
[image: Dual Axis Blade][image]Fig-1: "**DUAL AXIS BLADE** tool that allows both axis to be confirmed level"
[image]
1.3.1 DUAL AXIS BLADE [FIG1] ------------------------------
Provides confirmation that the headshell mounting surface is parallel to the surface of the record, in two axes. This is an essential "starting point" (a baseline reference) to ensure accuracy and repeatability when mounting your cartridge. Allows you to target an ideal SRA/VTA and azimuth simultaneously.
[image: Front/Back AXIS Blade][image]Fig-2: "**FRONT/BACK AXIS BLADE**: Alignment tool that allows VTA/SRA checks"
[image]
1.3.2 FRONT/BACK AXIS BLADE [FIG2] ------------------------------------
Once the cartridges native SRA and VTA has been determined by microscopy, the front/back blade allows the user to both measure (and then set) the best tonearm elevation that allows the for the ideal SRA/VTA. Once again an essential "starting point" (a baseline reference) to ensure accuracy and repeatability when mounting your cartridge.
[image: Left Right Blade][image]Fig-3: "**LEFT/RIGHT BLADE**: Alignment tool that allows azimuth checks"
[image]
1.3.3 LEFT/RIGHT AXIS BLADE [FIG3] ------------------------------------
Following the raising or lowering of the tonearm to achieve the ideal SRA/VTA, this blade allows a re-leveling of the headshell on the left/right axis.
[image: Feeler Gauges][image]Fig-4: "**FEELER GAUGE**: Gauges to determine angles"
[image][image][image]
1.3.4 FEELER GAUGES [FIG4] ----------------------------
The feeler gauges are used to measure the height of gaps that convert to angles for front/back and also right/left angles (up to 2 degrees)
[image: Stacking Spacers][image]Fig-5: "**Stacking Spacers**: Spacers adjust height of gauges."
[image][image]
1.3.5 STACKING SPACERS & SCREWS [FIG5] ----------------------------------------
Stacking spacers used to adjust blade height to match the measured cartridge height. Screws to mount the blades to the headshell.
[image: REF Ruler][image]Fig-6: "**REF Ruler**: Ruler to measure height."
[image][image][image]
1.3.6 35 mm RULER [FIG6] --------------------------------
An accurate 35 mm ruler used to measure the height of the mounted cartridge when under normal VTF load.
[image][image][image][image][image]
1.4 INTRODUCTION ==================
Common setup wisdom related to adjusting SRA/VTA suggests that 'as the rear of the arm is raised, the resultant sound becomes brighter and bass becomes more lean' with the corollary "As you lower the rear of the arm, the cartridge bass will sound heavier, and the treble dulls.'
Unfortunately, this generalization/platitude is not consistent; The *truth* is slightly more complex - what you hear when raising or lowering the tonearm is the impact that changed 'force vectors' create in the tonearm arm-wand, and thus to the stylus/cantilever/armature system. These changes alter the sonic attributes of the mass/spring system, but (significantly) affect each cartridge/tonearm combination differently.
If this oft-spun axiom (above) about the "sound" of raising/lowering tonearm height were *true* (about SRA/VTA), then most of the cartridges Engineering optimizes would sound horribly muddy, dead and lacking in any high frequency vitality. However, that is the exact opposite of what we and our clients find. There are other forces at play when the tonearm height changes [vectors].
Getting back on track, as a general rule your tonearm will perform best (dynamically) when level and "horizontal": Avoid exceeding more than one degree 'tilt' from this "level" target (VTA may require up to 2.5 degrees of adjustment, depending on the stylus profile) and make any changes to SRA/VTA from within the headshell using a corrective shim, while maintaining the arm-wand "level". Engineering has a wide variety of corrective shims available, and you can also make your own VTA/SRA shims and then use the Reference Front/Back Blade (with the feeler-gauges) to confirm the effectiveness of the constructed shim.
Most literature, AES papers, and lathe-master's notes point to a VMA [Vertical Modulation Angle] of 18 degrees (a midway point between the old 15 degree suggested standard, and the new 20 degree suggested standard), so a VTA measured with the stylus/cantilever/armature under load (ergo: with a correct VTF and with disc playback 'friction') should target this value. This "18 degree" value is what most lathe operators shoot for with their cutter-heads, and accounts for the lacquer spring-back, waif discard clearance and vertical modulation pre-distortion. But as a general rule, anywhere from 15-20 degrees of VTA on playback can produce excellent results, depending on the records used.
More mysterious are citations for "optimal SRA" (often cited to be 92 degrees); This value is less certain, as this playback stylus rake angle has **never** been *scientifically studied*. The only paper written on the subject [Risch, Jon & Maier, Bruce R.:"More than one Vertical tracking error" Audio, Volume 65, Number 3, MARCH 1981 pp. 21-25] was not detailed enough to be peer reviewed, and cited the target angle of 92 degrees as "being the optimal angle" but did **not** include guidance on whether this was to be measured statically or dynamically.
Given what we know of the rake angle most engineers cut at (typically between 80 to 90 degrees) plus the effect of lacquer spring-back, it is plausible (but unconfirmed) that the optimal range for SRA is 90-93 degrees. But until a controlled study of SRA is performed (as Engineering plans to do), and until the repeatable test results have been published and peer reviewed, the best available information we have is a SRA target between 90-93 degrees. As the VMA [Vertical Modulation Angle] angle is what lathe cutter engineers actually measure, VTA is likely more important than SRA (a topic to be covered in forthcoming videos) so (for today) err in favor of calibrating VTA - ergo: give this attribute more weight.
If you can get within the set target ranges, you are optimizing your playback performance. Getting your cartridges SRA and VTA equal the effective cutting rake and vertical modulation angles used to cut the lacquers which made your record will result in greater sonic clarity, focus, transient speed, inner detail, sound-staging and imaging .
1.5 PROCEDURE TO FOLLOW [PRINCIPLE USE] =========================================
1. Start by installing your cartridge in the middle of the headshell slots (neither alignment nor connections are necessary just the mounted mass.)
2. Adjust the tonearm counter weight to set the vertical tracking force (VTF) at the mid-level of the cartridge manufacturers recommended range (we need to depress the cantilever/armature with a nominal tracking weight).
3. Place a flat [warp-free] record (but **not** one that is 'dear to heart', as some scuffing can ensue) from your collection that is about average thickness on the platter. Install your record clamp and/or engage your vacuum hold-down system if capable. Ensure the tonearm clips are "out of the way" and are not touching the record when the stylus is lowered to the record surface.
[image: Measure from surface to headshell/cartridge interface][image]Fig-7: "Measure from the record surface to headshell/cartridge interface"
4. Use the included Reference 35 mm ruler and a (not included) magnifying glass to measure the height to the cartridge "under VTF load".
1. Measure from the record surface to the top of cartridge (bottom of the headshell) by placing the ruler as close as possible to (but not touching) the headshell or cartridge. Note the measurement to within a quarter mm (0.25 mm).
2. Repeat this process on opposite side of the headshell. If the two readings are different, take average of the two. This is your cartridge height. Write this cartridge height figure to the nearest 0.25 mm in the table at the end of these instructions.
[image: Mount in headshell to be parallel][image]Fig-8: "Mount Blade in headshell to be parallel and the same height."
STACKING HEIGHT SEPARATOR SIZES ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+-----------------+--------+ | Separator color | Height |
|=================|========|
| Brown separator | 0.25mm | +-----------------+--------+ | Yellow separator| 0.5 mm | +-----------------+--------+ | Clear separator | 1.0 mm | +-----------------+--------+ | Gray - Embossed | 2.0 mm | +-----------------+--------+ | Gray - Embossed | 3.0 mm | +-----------------+--------+ | Gray - Embossed | 4.0 mm | +-----------------+--------+
5. Remove the cartridge and install the Dual AXIS Blade Reference using enough stacking spacers between the Reference and headshell to match the exact height of the cartridge [under VTF load]. For example, if the measured height of the cartridge is 17.75 mm, use the Reference blades' "integral height" (15-16 mm, depending on version), plus one 'Gray' 2 mm spacer [if 15 mm], add one yellow spacer (0.5 mm) and one brown spacer (0.25 mm) to equal the total of 17.75 mm. An inexpensive plastic caliper [Look for "Plastic Vernier Caliper (2 piece)" on Amazon] is helpful to check and confirm that the total height correct. a. Align the central body of the Reference to be parallel with the headshell sides, i.e. not skewed or angled in the headshell.
Note:
The currrent versions of the Reference are 15 mm high -- previous versions where 16 mm high.
[image: Mount in headshell to be parallel][image]Fig-9: "Mount Blade in headshell to be parallel."
6. Lower the Reference Blade onto the middle of the record, keeping away from the shallower lead-in area of the record.
1. If your cartridge is heavier than the Reference, increase the tracking force and/or add weight to the top of the headshell so it can be lowered down to the record.
7. With your eye at record level, (and a small flashlight to provide background illumination of 'gaps') view the Dual Axis Reference blade where it meets the record surface. Adjust the tonearm height and azimuth so the Dual Axis blade's bottom edge is touching the record along its full length and on both axes. You may have to press down on the record to eliminate any warps that will make leveling impossible.
1. An adjustment to the tonearm height can cause a change to azimuth angle and vice versa. You may have to adjust tonearm height and azimuth a couple times to get them both level.parallel.
8. Once the leveling process is complete, slightly tighten your tonearm settings to retain the current geometry, and then remove the Reference from the headshell and store your pieces away. You are now assured that the substituted cartridge will have an optimal starting point with regards to both axes.
9. Remount your cartridge in the (now parallel) headshell and lightly tightened the screws - you are now ready to use other reference tools (like the Tractor) to implement the optimal arc geometry.
10. You could theoretically "stop" here [as far as SRA/VTA is concerned] and **hope** that your cartridge was manufactured to perfection [stylus is perpendicular (in all axis) to the cartridge body and (especially) the cartridge mounting surface] - but this is exceedingly rare, regardless of price of the cartridge. To ensure optimal performance from your turntable, you should consider the following steps:
1. Use a Scope (or other microscopy) to achieve the measured nominal SRA and the target VTA for your cartridge.
2. Use electronic measurement to maximize the stereo separation (via measuring cross-talk). Measure and document the resulting azimuth angle X as to make quick and easy work when re-mounting this cartridge to any tonearm (instructions for this below).
1.6 ADDITIONAL USES =====================
1.6.1 ADJUSTING HEADSHELL ANGLE FOR IDEAL SRA & VTA -----------------------------------------------------
This step is performed when mounting a cartridge for which the ideal SRA/VTA correction is already known, A "SRA/VTA correction is any angular change from level headshell *required* to achieve the targeted ranges for SRA and VTA (see page3above)
1. Install the Front/Back (SRA/VTA) Reference blade. Use enough height separators between the Reference Blade and the headshell to match the exact height of the cartridge (steps 4 & 5 above for example).
2. Align the central body of the Reference Blade to be parallel with the sides of the headshell, i.e. not twisted
3. Lower Reference to a flat record. a. If your cartridge is heavier than the Reference you may have to adjust the tracking force and/or add weight the headshell area to allow the Reference to lower to the record.
[image: Shims][image]Fig-10: "SRA/VTA Shims available from Engineering."
4. Change the height of the tonearm and/or add corrective shim to achieve the target SRA/VTA.
1. If you have added a corrective shim, increase height of the tonearm to accommodate its nominal thickness.
2. Every 1 mm of space the blade lifts above the surface of the record equals a 1 degree angle of tilt from a level headshell.
3. Use the feeler gauge to determine the maximum thickness that will fit under the lifted corner of the blade without resistance. The thickness of the feeler gauge equals the angle. Keep your finger on the corner of the blade that touches the record as to allow the feeler gauge to lift the blade off the record and there by nullify the measurement.
4. If the angle is greater than 2, simply use the 2 mm, 3 mm or 4 mm Stacking separator PLUS the Feeler Gauge to measure the angle.
[image: Feeler Gauge in use.][image]Fig-11: "Feeler gauge in use."
5. You are done with the SRA/VTA alignment process. Document the measured angle in the table "Ideal front/back blade angle" column on in the table at the end of these instructions.
Note:
Tonearm height changes can affect left/right (azimuth) angle. Changes in tonearm height can also cause unintended changes to the azimuth angle of the headshell. This is less of a concern for arm with an offset yoke (see inset photo) but such arms are still somewhat at risk of having changes to tonearm height also change the azimuth angle.
[image: Offset Yoke.][image]Fig-12: "Offset yoke type bearing can also be sensitive to height changes."
1.6.2 MEASURE THE IDEAL AZIMUTH ANGLE ---------------------------------------
1. Once maximum stereo separation has been determined using Azimuth or other electronic method, remove cartridge and install the left/right (azimuth) axis Reference blade. Use enough stacking separators between Reference and headshell to match the exact height of the cartridge.
2. Align the blade of the Reference to be perpendicular to the headshell. Tighten the cartridge mounting screws.
3. Lower the Reference blade on to the flat record
4. Measure the left/right (azimuth) angle of the blade/headshell
1. Every 1 mm that one corner of the blade lifts above r the surface the record equals 1angle from a level headshell
2. Use the Feeler Gauge to determine the maximum thickness that will fit under the lifted corner of the blade without resistance. The thickness of that feeler gauge equals the angle. Keep your finger on the corner of the blade that touch es the record so as to not allow the feeler gauge to left the blade off the record and there by nullify the measurement.
3. Generally, azimuth angles greater than 2.0 (Replicate stylus) to 2.6 (Japanese stylus) should not be used in practice as the risk of the stylus coming into contact with the junction of the record land (surface) and groove is significantly increased.
4. If the angle is greater than 2 degrees, simply use the 2 mm Stacking separator PLUS the Feeler Gauge to measure the angle.
5. Document the measured angle in the "Ideal Azimuth Angle" column and document the tilt direction in the "L/R Blade rotated clockwise or counter clockwise" column in the table at the end of these instructions.
1.6.3 MOVE CARTRIDGE TO ANOTHER TONEARM -----------------------------------------
As you have previously REFERENCED the ideal SRA/VTA & azimuth blade angles with the Reference tool and documented the angles in the table below, you have a very quick, easy and accurate method to repeat an ideal cartridge mount. These measurements are replicated by mounting the front/back (SRA/VTA) and left/right (azimuth) Reference blades to the tonearm with the appropriate stacking separators to replicate the height of the cartridge and - using the Shim Gauges and 35 mm Ruler adjust the tonearm to achieve the targeted blade angles by repeating the steps noted above in these instructions. No need to directly re-measure SRA/VTA or azimuth for your cartridge again until it is re-tipped or repaired by the manufacturer.
1.7 GENERAL NOTES ===================
* Always use stacking separators to get the height of the Reference blades to be identical to the height of your cartridge when measured under its appropriate vertical tracking force.
* Avoid using the Reference blades close to the outer edge of the record as many records get thinner in this area and therefore will give inaccurate results when using a blade against this tapered record surface area.
* Always keep finger pressure on the opposite end of the blade to keep it from lifting off the surface of the record when using the Feeler Gauge. This also sometimes helps to remove record warps.
* Use a combination of the stacking separators and the Feeler Gauge when measuring gaps greater than 2 mm between the lifted corner of the blade and the record.
* DOCUMENT RESULTS in the table below. This allows you to know how to install the cartridge very quickly on any tonearm without remeasuring the SRA & VTA and azimuth of your cartridge.
* When any of the single axis blades are NOT level to surface of record: each 1 mm of distance between the record surface and blade tip equals 1° of angle off of a level headshell
* We discourage adjusting the tonearm height for varying record thicknesses. The difference between the thickest and thinnest records is around 1. 1 mm. On a 9” tonearm, a 1. 1 mm difference will be the equivalent about 0. 25° change in SRA/VTA and even less on longer tonearms. A 0. 25° SRA/VTA change is at or under the limit of perceptibly on even the best systems. Therefore, we take the position that the small benefit achieved by constant adjustments for record thickness gets in the way of enjoying the music and, ultimately, puts extra wear on the adjustment mechanism itself. Our engineering software analysis of the mechanical impact of changes to SRA/VTA suggests that if you are hearing a change in as little as 1 mm tonearm height changes, you are hearing the effects of changes incurred by vector forces, not SRA & VTA.
Contact us if you have any questions.
ENJOY ANALOG FOREVER !!! Mr. Malewicz
1.8 APPENDIX ==============
SRA/VTA vs. ARM HEIGHT CHANGE RELATIONSHIP ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+------------------------------------------+------------------------------------------+ | Tonearm Effective Length | Rear Height (mm) for 1 degree change | |==========================================|==========================================| | 220 | 4.2 mm | +------------------------------------------+------------------------------------------+ | 230 | 4.4 mm | +------------------------------------------+------------------------------------------+ | 240 | 4.6 mm | +------------------------------------------+------------------------------------------+ | 250 | 4.7 mm | +------------------------------------------+------------------------------------------+ | 260 | 4.9 mm | +------------------------------------------+------------------------------------------+ | 270 | 5.0 mm | +------------------------------------------+------------------------------------------+ | 280 | 5.2 mm | +------------------------------------------+------------------------------------------+ | 290 | 5.4 mm | +------------------------------------------+------------------------------------------+ | 300 | 5.5 mm | +------------------------------------------+------------------------------------------+ | 310 | 5.7 mm | +------------------------------------------+------------------------------------------+
For tonearms that do not have an offset yoked horizontal bearing (see above for photographic description), use the "SRA/VTA Change to Azimuth Calculator" on wallyanalog.com - site will tell you how much azimuth is affected by tonearm height changes.
ANALYSIS RESULTS ^^^^^^^^^^^^^^^^
+--------------------------------+------+-------+------+-------+---------+ | CART | DATE | VTF | HIEGHT| F/B |AZIMUTH|ROTATION | |================================|======|=======|=======|======|=========| | Tri-Art P-Ser Shibata | 4OCT24 | 2.0g | 17 mm | 0-deg | 1-deg| Counter-| +--------------------------------+------+-------+-------+------+---------+
A negative number requires a DECREASE in tonearm height from level (blade corner furthest away from pivot point lifts above record surface);Positive number requires INCREASE in tonearm height (blade corner closest to pivot point lifts above record surface) When viewed from the front of the cartridge, Clockwise means the *right* blade corner is lifted off record. Counter clockwise means the *left* blade corner is lifted off record
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