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
|