WHY IS USE OF THE WALLYREFERENCE IMPORTANT?
One of the main functions of the WallyReference is to easily and repeatedly determine a reference point where the cartridge mounting surface/lower plane of the headshell is perfectly parallel to the surface of the record in both the front/back (Stylus Rake Angle, “SRA”) and left/right (azimuth) axes as well as to determine exact angles of the cartridge required to have ideal SRA and azimuth.
Cartridge manufacturers endeavor to align the stylus to approximately 92 degrees Stylus Rake Angle (SRA) when the cartridge has nominal tracking force applied and the top surface of the cartridge is level to the record. (See WallySchool! Blog for articles on this.) An acceptable stylus mount should be off by no more than ±2.0 degrees. The WallyReference is the only way to be sure you get the top surface of your cartridge level every time as a starting point.
Cartridge manufacturers also try to align the stylus and motor assembly of the cartridge so that proper azimuth (offering maximum stereo left-right separation) will be found at a setting perfectly perpendicular to the record. The WallyReference will ensure your cartridge is level on this axis as well.
Cartridge setup is only truly optimized once its ideal SRA is determined via microscopy and azimuth electronically. Once performed, the WallyReference can be used to allow fast and easy re-mounting of the cartridge at the ideal SRA and azimuth on ANY tonearm without microscopy or electronic remeasuring.
WHY IS IT IMPORTANT TO ENSURE A LEVEL SURFACE ON BOTH AXES SIMULTANEOUSLY?
Because pivoted tonearms have an offset angle, changes to tonearm height/SRA will impact azimuth (exception below). Conversely, changes to azimuth will impact SRA . As a result, to confirm the front/back axis (SRA) is level, you must simultaneously ensure the left/right (azimuth) is also level.
Exception: Azimuth that is adjustable at the headshell where the adjustment plane is perpendicular to the horizontal alignment of the cantilever. Such "true azimuth" designs allow for adjustments to azimuth without impact to SRA. If you have a removable headshell offering azimuth adjustment AND the headshell slots are cut parallel to the length of the headshell (not at an angle to the headshell length) then you can adjust azimuth without impacting SRA.
HOW ACCURATELY DO MANUFACTURERS MOUNT THE STYLUS?
At WAM Engineering we have seen many cartridges with an improperly mounted stylus such that when the top of the cartridge is level with the surface of the record and set to a nominal tracking force, the SRA is far off of ideal. Given the many poor stylus mounts we have seen, we also know there is not a correlation between high cartridge price and high accuracy. We have seen multiple >$10,000 cartridge as far off as 87° and 96°!
To know for sure whether your stylus was mounted properly it must be inspected under a microscope with the stylus/cantilever assembly under nominal tracking force with a perfectly level top surface and viewed at the proper perspective with detailed measurements taken. You may try this at home with the right equipment and patience or contact WAM Engineering for this service. The WallySRA (available in late 2020) makes this process much more accurate and easier.
Following analysis under microscope, it can be easily calculated how many millimeters you will have to raise or lower your tonearm in order to get a perfect SRA once the reference has been first set by use of the WallyReference. The WallyReference can then also allow you to compensate for the impact of the change to SRA by changes in azimuth.
WHY NOT ADJUST SRA BY EAR?
Many people believe that adjusting SRA by ear is “good enough”. Unfortunately, adjustments to SRA also result in a change to azimuth (and vice versa) and often to vertical tracking force as well (which itself upsets SRA!). Therefore, each SRA adjustment “by ear” is a change to two or three of the most critical setup parameters. As a result, the changes you hear are multi-dimensional, making setup by ear a far more difficult proposition than is commonly acknowledged, and certainly impossible to CONFIRM.
When a parameter is measurable and the ideal alignment is knowable then why would we rely on our ears? When adjusting by ear we may find a particular setting that “sounds best” but since no measurements were taken, we would not know that the “best sounding” setting is only compensating for problems elsewhere in the system. For example, if our speakers are not setup well or are a bit aggressive on the top end, when adjusting the tonearm by ear we unknowingly choose a far lower SRA setting to provide softening of the high frequencies. This lower SRA setting may “sound best” but the result will be also to miss out on plenty of inner detail and dynamic slam with imaging/soundstaging also suffering. It’s best to fix the systemic problem rather than compensate for it with poor alignment.
Further, if your stylus was poorly mounted at the factory, you may never be able to hear what ideal SRA sounds like before bottoming out the armtube on the record or pulling the arm out of its base. Since arm height must change by 4mm-5.5mm for each 1° change in SRA (depending on tonearm length), if your stylus was mounted at 87°, you’d have to move the arm height up by as much as a full inch or more from level to get the proper SRA! Most tonearms can’t do that, and you wouldn’t want the performance disadvantages of a severely angled tonearm if you could.
WHAT ABOUT ADJUSTING SRA ELECTRONICALLY?
There are some proponents of measuring SRA electronically. While we love having ways to measure what is measurable, just as with the “setting SRA by ear” method, any change to SRA will impact azimuth and, often, VTF. This makes the process maddeningly iterative, time consuming and frustrating. Further, this process will not reveal what a microscope can – a flawed stylus mount. SRA is something that must be established optically as the results are independent of all other parameters.
But that is the point, isn't it?: Since each parameter CAN be optimized independently without influence from other setup parameters, why be severely disadvantaged by trying to make sense out of each setup parameter using a method in which all parameters are simultaneously influencing the results?
HOW IS WALLYREFERENCE USED WITH WALLYSRA & WALLYAZIMUTH?
The WallySRA will allow you to optically confirm the “native” Stylus Rake Angle of your cartridge when it has been perfectly leveled under nominal VTF and photographed from the proper perspective. Once the WallyReference has been used to perfectly level the headshell, you will then know how much to raise or lower your tonearm height in order to achieve a perfect 92.25° to 92.5° SRA (under static conditions and depending upon your cartridge compliance and stylus profile – exact target will be in the WallySRA instructions).
For captured bearing tonearms: As you raise or lower your arm height with the WallyReference mounted, the front-back plane of the WallyReference will no longer be parallel to the record but, with the use of the WallyReference measurement gauges, you can make the necessary adjustments to your azimuth setting so azimuth remains unaffected by the change in tonearm height.
The WallyReference is also used with the WallyAzimuth in the same manner: to establish “perfectly level” on captured bearing tonearms which then allows for an easy method to measure what the ideal azimuth tilt for your cartridge is. Further, the WallyReference will allow you to compensate for changes to your SRA as a result of any azimuth adjustments made.
HOW DOES THE WALLYREFERENCE ALLOW FOR QUICK AND EASY SWAPPING OF CARTRIDGES BETWEEN TONEARMS?
Once you have determined YOUR cartridge’s SRA via optical method and azimuth via electronic method the WallyReference and its measurement gauges provide a REFERENCE from which you can quickly and easily set the SRA and azimuth on any other tonearm for your cartridge and get identical results without having to measure, analyze and listen again.
NOTE: As there is a significant mechanical tolerance between cartridges allowed by many manufacturers, you cannot assume the ideal settings on one cartridge will mean another cartridge of the same type will need the same SRA and azimuth settings, but the WallyReference will at least allow consistency in settings for the same cartridge across multiple tonearms.
WHAT IF MY TONEARM DOES NOT HAVE AN AZIMUTH ADJUSTMENT?
Sorry for you! Azimuth is one of two setup parameters that arguably has the largest impact on your playback optimization (along with SRA). However, in the near future WallyTools will be offering a solution to allow azimuth adjustment on tonearms that do not have an azimuth mechanism.