The most obvious production defects can usually be detected with a sharp look at the needle carrier and needle. A magnifying glass or USB microscope can help enormously. If the needle or the needle carrier is obviously mounted crooked, you should complain about the cartridge at the dealer (from a certain price range mandatory!). Slight misalignments can be compensated by the mounting angle in the headshell.
How to correct crooked needle carriers and diamonds
What can only be corrected by adjusting the azimuth on the tonearm is a laterally slightly skewed diamond, which unfortunately occurs in 80% of all cases with MC cartridges. If you want an exact position of the needle in the groove and thus a perfect result, you have to measure and correct the azimuth. Many do this by ear. Respect, who can do that!
A little more professionally and above all faster it goes with a software (for it you need a good sound card and a PC): Adjust+ of Dr. Feickert measures for the azimuth fine adjustment the channel separation and the phase. If you want to do it exactly, you need the Level Difference Meter PDM-1 from Sperling Audio, which we use as a service for our customers.
The goal of an azimuth measurement is always to create as equal a channel separation as possible through different angular positions of the headshell. With well-produced pickups, the corrections are +/- 0.5 degrees or less to achieve the desired position. This sounds like little at first, but at one degree you can see the “skew” more than clearly. Pickups that show more than 1.5 degrees deviation for an optimal azimuth should be sent back together with the measurement report. That’s just not the way it works, dear industry. And for this reason, some cooperations or trade relations with Bohne Audio have already been terminated again. Because we measure pickups for you on request.
Tonearms without azimuth adjustment – not possible at all
A tonearm that does not offer azimuth adjustment is, in our view, poorly implemented – the above reasons speak for themselves. Yet there are several great concepts for this: On headshells like the Thomas Schick Graphite Headshell or the Arche Headshell from Acoustical Systems, you can loosen a screw to turn the headshell.
The Reed 3P tonearm, which we hold in high esteem, allows azimuth adjustment while playing a record (!) by rotating the entire arm tube (you should then adjust the counterweight “straight” down again).
And on a Kuzma 4 Point, the arm tube is split into two parts, and the front part can be rotated in extremely small and precise increments with the associated Allen key, without affecting the rear part of the tonearm including the bearing in any way.
Excitingly, the azimuth correction is also solved with a Well Tempered tonearm, here you turn the thread suspension back and forth. (This is also possible during playback.) As you can see, there is no lack of creative solutions, and the results after a successful azimuth correction are absolutely worth hearing!