Rake angle adjustment wedge set for AudioTechnica VM95 cartridge

thingiverse

Extracting maximum quality from an LP, a surprising number of parameters have to be spot on. Your pickup cartridge must be positioned just right on the tonearm. Not only parallel with the housing, but also longitudinally (overhang), vertically (azimuth) and with what I now know is called the rake angle. That is, the angle at which the needle sits in the groove when viewed from the side. In short, the stylus contact patches must be correctly aligned with those of the cutting head as used during mastering. Bloody complex... Oh well. We're here to figure things out, right? Slots in the tonearm headshell allow for overhang and parallelism adjustment. Some tonearms have headshells that allow for a slight rotation to address the azimuth issue and some also have adjustable height arm bases to let you adjust stylus rake angle. And some don't. Here's where you have to get creative. If the arm sits fixed, a wedge will have to be inserted between cartridge and tonearm shell, tilting it to the correct rake angle. This 'thing' is a selection of wedges that fit Audio-Technicas brand new line of moving magnet cartridges, tilting them slightly forward. Because that's what I needed when installing a VM-95SH cartridge to a Rega RB300 arm. The AT cartridge is taller than Rega's cartridge offerings, making it tilt backwards when installed. So, a wedge was needed to compensate. Three variants in 1.2, 1.4 and 1.6 degree angles were made to facilitate experimentation. Edit: A revised set is under consideration; I plan to add a 'ridge' down the middle of the wedge to make azimuth adjustment on fixed-headshell systems possible. This may, given the topology of the VM95 cartridge contact plane, be an issue. Instead a 'generic edition' for cartridges with a different and more usable topology will be published. I expect few takers for this thing. But maybe you will take away some inspiration... Educational articles on stylus shapes and turntable adjustment (geek stuff): https://www.sound-smith.com/articles/stylus-shape-information https://www.sound-smith.com/soundsmith-cartridge-alignment http://www.theabsolutesound.com/articles/setting-up-a-phono-cartridge/