Also known as a valve.
What are vacuum tubes and what is their role in microphones? Vacuum tubes are devices that control the flow of electric current in a vacuum between electrodes when a voltage has been applied. A tube in an active mic acts as an amplifier of the mic signal. Tube circuits have largely been replaced by FET circuits since the invention of solid-state electronics.
Variable Input Impedance:
What is variable input impedance and why is it important to microphones? Variable input impedance typically applies to mic preamps that are capable of different input impedances. Because mic output impedance is frequency-specific, varying the load impedance (preamp input impedance) will literally change and shape the sound of a connected microphone.
What is the Variable-D microphone technology? Variable-D is a trademark by the American microphone manufacturer Electro-Voice. Variable-D technology refers to specially designed acoustic labyrinths (that resemble interference tubes) that eliminate the proximity effect from directional microphones.
What is a velocity microphone? A velocity mic is a theoretical mic that reacts to the velocity of individual air molecules hitting its diaphragm. To achieve this, the diaphragm would be infinitely light (to respond instantaneously) and infinitely thin (for equal pressure on the two sides). Ribbon mics are closest to this ideal.
Very-High Frequencies (VHF):
What are very-high frequencies? Very-high frequencies in a microphone could refer to the highest range of human hearing (perhaps 12 kHz – 20 kHz). However, very-high frequencies (VHF) almost always refer to the range of radio frequencies between 30 MHz – 300 MHz, which is sometimes used by wireless mic systems.
Very Low Mass (VLM):
What does Very Low Mass mean in reference to microphones? Very Low Mass (VLM) is a trademark by the American microphone manufacturer Audix. Audix utilizes VLM diaphragms in many of their dynamic microphones for an improved transient response.
What is a vintage microphone? A vintage microphone is an older mic that typically has gone up in value over time. Vintage mics are sought after by audiophiles, musicians, and engineers for their fame and characteristic sounds. Many vintage mics are either high-quality ribbons or tube condensers that have stood the tests of time.
To learn more about vintage microphones, check out my article Top 12 Best Vintage Microphones (And Their Best Clones).
What is a microphone voice coil? A voice coil is a coil of conductive wire that is attached to a moving-coil dynamic mic's diaphragm. The voice coil is surrounded by, but not touched by, magnets. As the diaphragm/voice coil element vibrates in the magnetic field, electromagnetic induction takes place and a mic signal is created.
For a detailed read on microphone voice coils, check out my article What Is A Microphone Voice Coil?
What is a volt and why is it important to know when using microphones? The volt (symbol: V) is the derived SI unit of electrical potential difference or voltage. Microphone signals (analog audio signal) are AC electrical signals and are most commonly measured in millivolts (thousandths of a volt). Phantom power and DC-bias are DC signals and are measured in volts.
What is voltage and why is it important to microphones? Voltage is the electric potential between two points measured in volts. It can be envisioned as the “pushing” force for current in an electrical circuit. Microphones are transducers that convert mechanical wave energy to electrical energy and mic signals are electric signals measured in AC voltage.