Sunday, February 5, 2017

How a MM Phono Cartridge Works

How a MM Phono Cartridge Works

Phono amplifier is designed for a phono signal amplification while using Turntables amplifier inside for special sound equalization circuit (RIAA) for restoring vinyl, it cannot be used for other purposes. But do you know How a MM Phono Cartridge works -- the key component that pick up the signal from the LP vinyl which is amplified.





A MM phono cartridge is a micro-manufactured electromechanical device that tells your entire audio system what is happening along the half-mile groove that is cut into a typical analog disk.

Phono cartridges contain transducers that convert one form of energy into another. Phono cartridges do it by translating variations in the groove walls into electrical signals. Great inventer Thomas Edison pioneered this technology way back in 1877 using a stylus on a tinfoil or wax cylinder.

The stylus (needle) moves horizontally and vertically as the groove of the record travels underneath it. A coil of wire and magnet at its other end generates a small audio signal.

Since then, there are two main types of phono cartridges: moving magnet (MM) and moving coil (MC). A tiny magnet rests on the end of a stylus shank that is suspended between two coils. The vibrating magnet induces a small current in the coils. 



To decide which phono cartridge will work best for you that depends on a few factors.

You will need to know how the cartridge attaches to the turntable you have or are going to buy. There are two types as below.

Standard mount that is far the most common: Two screws, half an inch apart, thread through the cartridge body to secure it to the headshell, which then plugs into the tone arm.

P-mount that is The four prongs at the back of the cartridge plug directly into the tone arm. A setscrew goes through the side of the cartridge at the back to hold it in place on the tone arm.

Elliptical (Bi-radial) or Spherical Stylus

The stylus (or needle) is really the heart and soul of the cartridge and accounts for about 90% of the cost of it.  Almost all styli have industrial diamond tips. There are two needle shapes: elliptical and spherical. Elliptical needles pick up more information from the record groove and are typically the choice of audiophiles. DJs choose spherical needles because they sit higher in the groove and result in less record wear.


Finally, a LP Turntables Tonearm Signal Cable from the output of MM phono cartridge will be connected to phono stage amplifier to amply weaker signal.There is a HIFI LP Turntables Tonearm Signal Cable that is good partner for connecting them.