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” & Vertical Tracking Angle, "VTA") and left/right (azimuth) axes as well as to determine exact angles of the cartridge required to have ideal SRA/VTA 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.) 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 and VTA 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/VTA 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 (which cause changes to SRA/VTA) will impact azimuth (exception noted below). Conversely, changes to azimuth will impact SRA/VTA on indirect azimuth tonearms, but not on true azimuth tonearm designs. As a result, to confirm the front/back axis (SRA/VTA) is level, you must simultaneously ensure the left/right (azimuth) is also level.
Exception: Tonearms with an offset yoke for the horizontal bearing will not cause changes to azimuth angle when tonearm height is changed.
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 >$5,000 cartridges as far off as 86° and 103°!
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. The WallyScope makes this process much more accurate and easier or you can send your cartridge to us for analysis.
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/VTA BY EAR?
Many people believe that adjusting SRA/VTA by ear is “good enough”. Unfortunately, adjustments to SRA/VTA - by raising/lowering the tonearm - often also result in a change to azimuth and to vertical tracking force as well which also upsets SRA/VTA. Changing tonearm height also affects vector forces about the tonearm pivot. Therefore, each SRA/VTA adjustment “by ear” is a change to two or three critical setup parameters and also the mechanical behavior of the arm itself. 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/VTA setting to provide softening of the high frequencies. This lower SRA/VTA 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 is 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/VTA 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/VTA ELECTRONICALLY?
There are some proponents of measuring SRA/VTA electronically. While we love having ways to measure what is measurable, just as with the “setting SRA/VTA by ear” method, any change to SRA/VTA can impact azimuth and VTF - which affects skating force and cantilever angle. This makes the process maddeningly iterative, time consuming and frustrating. Further, this process will not reveal what a microscope can – a flawed stylus mount. While VTA can be optimized electronically using square waves in a test record, no reliable and repeatable test exists for SRA. SRA/VTA is best 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 WALLYSCOPE & AZIMUTH MEASUREMENTS?
The WallyScope will allow you to optically confirm the dynamic SRA and VTA of your cartridge when it has been perfectly leveled under nominal VTF. 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 as close as possible to 92° SRA and <22° VTA under dynamic (record playing) conditions.
Captured bearing tonearms: As you raise or lower your arm height with the WallyReference mounted, the front-back blade 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 process of measuring azimuth electrically 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/VTA 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 dynamic SRA/VTA using the WallyScope and your ideal azimuth via electronic method the WallyReference and its measurement gauges provide a REFERENCE from which you can quickly and easily set the SRA/VTA 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/VTA 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. However, we have the solution. Check out the WallyFulcrum.