Setting Styles Rake Angle to 92 degrees (SRA) with a USB Microscope

Vinyl records have made a notable comeback in recent years. But while you’re attracted by their distinctive charm, how can you be sure you’re getting the best sound quality?

In many cases, subpar sound quality can be traced to the angle of your stylus rake.

Poorly aligned elliptical styluses can ‘bump’ into the vertical modulations instead of properly tracking them, leaving you with an inferior audio experience.

However, it can be difficult to find the right angle by ear, leaving your audio quality up to chance more often than not.

Fortunately, there’s a more reliable method on How to use a USB digital microscope to set stylus rake angle (SRA) at 92 degrees

By using a handheld digital microscope such as the Dinolite AF3113T, you can see well enough to accurately measure the rake angle of your stylus and make adjustments as needed.

With the Dinolite's excellent image quality and measuring software, you’ll be able to ensure that your stylus is sitting at the preferred angle of 92 degrees.

Requirements 

Here’s a step-by-step guide to help you with the process but first you’ll need:

• A Dinolite AF3113T microscope or similar
• A Dino-Lite stand
• A computer/laptop
• A spare CD
• A fair bit of patience!

Step-by-step guide

1. Connect your Dinolite AF3113T to your computer or laptop and follow the instructions to install Dinolite’s microscope software.
2. Gently remove the plastic LED shield from the microscope as instructed.
3. Set the magnification to around 200x and place the microscope securely in your stand.
4. Check that the tonearm on your turntable is parallel to the platter.
5. Position a CD on the platter, shiny side-up, making sure it slightly protrudes off the edge.
6. Lower the stylus onto the CD with great care, then very gently move the tonearm until the stylus is close to the edge of the CD.
7. Position your microscope (on its stand) close to the platter and CD, aligning it as parallel as possible. You should be looking straight across the surface of the CD, side-on at the stylus.
8. Use the microscope to bring the edge of the CD into focus. You may need to gently adjust the CD's position carefully to achieve this.
9. Once the edge of the CD is in focus, cautiously slide the stylus to the edge of the CD until it also comes into focus.
10. If the stylus is hard to see against the background, improve contrast by placing a piece of folded paper behind the tonearm. You can also adjust the lighting using the microscope’s software.
11. Use the software to take a photo of your in-focus stylus.
12. Use the measurement software to determine your rake angle. Your best option is the ‘3 point angle’ function, which allows you to pick any three points on your image and automatically determine the angle between them. Pick a point on the CD’s surface under the arm, the point where the stylus makes contact with the CD, and a point at the top of the stylus along its central axis. This will give you a good approximation of your rake angle.
13. Once you know the angle, you can make adjustments and remeasure to see if you’re close to the preferred angle of 92 degrees.
14. Repeat the process as needed until you achieve the correct stylus rake angle for optimal sound quality.

This process can require quite a bit of patience and precision, but you’ll be rewarded with a richer audio experience and a new outlook on your beloved vinyl collection.