A tube microphone, also known as a valve microphone, is a type of microphone that uses a vacuum tube to amplify the audio signal. These microphones have a warm and rich sound that is often preferred for recording vocals, acoustic instruments, and drums. In this article, we will explore the differences between tube and FET microphones, the history of tube microphones, some popular tube microphones, and what you should record with a tube microphone. So, let’s get into it!
The Difference Between a Tube and FET Microphone
To understand the difference between a tube and FET microphone, we must first understand the mechanics of each type. A tube microphone uses a vacuum tube to amplify the audio signal, while a FET (Field Effect Transistor) microphone uses a transistor to amplify the audio signal. The primary differences between these two types of microphones are in their mechanics and sound.
The Mechanical Differences
Tube microphones have a vacuum tube in their preamp stage, which amplifies the audio signal. The tube can be seen as a cylindrical glass bulb that contains a filament and a cathode. When voltage is applied to the filament, it heats up, causing electrons to flow from the cathode to the anode. This flow of electrons creates an electrical current, which amplifies the audio signal. This extra power is supplied by an external power supply, typically included with the mic, so you don’t actually need phantom power to operate a tube mic. However, you will need to plug the power supply into a wall outlet to give it power.
FET microphones, on the other hand, use a field-effect transistor in their preamp stage to amplify the audio signal. A FET is a type of transistor that uses an electric field to control the flow of current. This is the typical style of condenser microphone you’ll find in most studios. Almost all condenser mics are FET mics unless otherwise noted.
The Differences in Sound
One of the primary differences between tube and FET microphones is their sound. Tube microphones have a warm and rich sound that is often described as “musical.” They can add a pleasing saturation and harmonics to the audio signal, giving it a vintage feel. FET microphones, on the other hand, have a more transparent sound that is ideal for recording clean, detailed audio.
A Brief History of Tube Microphones
Tube microphones have been around since the early 1900s. The first commercially successful tube microphone was the RCA 44, which was introduced in 1931. The RCA 44 was a ribbon microphone that used a vacuum tube in its preamp stage. It quickly became a favorite among recording engineers for its warm and rich sound.
In the 1940s, German microphone manufacturer Neumann introduced the U-47, which quickly became the gold standard for recording vocals. The U-47 used a vacuum tube in its preamp stage and had a warm and rich sound that was ideal for recording vocals and acoustic instruments. It was used by many of the top recording artists of the time, including Frank Sinatra and Elvis Presley.
Notable Tube Microphones
The Sony C-800G is a modern tube microphone that has become a favorite among recording engineers for its warm and detailed sound. It uses a large-diaphragm capsule and a vacuum tube in its preamp stage to deliver a rich and detailed sound. The C-800G has been used by many top recording artists, including Beyonce and Justin Timberlake.
The Neumann U-47 is a classic tube microphone that has been used on countless hit records. It was introduced in 1949 and quickly became the go-to microphone for recording vocals and acoustic instruments. The U-47 uses a vacuum tube in its preamp stage to deliver a warm and rich sound that is still highly sought after today.
The Manley Reference is a modern tube microphone that has been praised for its versatility and ability to capture a wide range of sources with clarity and warmth. It uses a dual-triode 12AT7 vacuum tube in its preamp stage and has switchable polar patterns, making it a flexible choice for recording vocals, drums, and instruments.
Other Tube Mics to Check Out
Lauten Audio LA-320
The Lauten Audio LA-320 is a relatively affordable tube microphone that has received high praise from many recording engineers. It uses a 1-inch pressure gradient capsule and a vacuum tube in its preamp stage to deliver a warm and detailed sound that is ideal for recording vocals, acoustic instruments, and drums. Check out our full review here!
- The LA-320’s onboard sound-shaping eliminates the need for mic swaps and wasted time. Choose between the warmth of a classic tube microphone and the clarity of a modern tube microphone at the flip of a switch.
- The LA-320 isn’t flat – it sounds like music.
- The LA-320 is hand-soldered with high-resolution, low-distortion polypropylene capacitors and resistors, a dual triode vacuum tube, and a vintage-inspired output transformer. The resulting sound is crisp, clear, and full without the high noise floor and delicacy of vintage microphones.
- Each LA-320 is lovingly designed and built to last a lifetime by the Lauten Audio family.
Warm Audio WA-47
The Warm Audio WA-47 is a modern take on the classic Neumann U-47. It uses a custom reproduction of the original K47 capsule and a JJ 12AY7 vacuum tube in its preamp stage to deliver a warm and rich sound that is ideal for recording vocals, acoustic instruments, and drums. You can check out our full review here!
What Should You Record with a Tube Microphone?
Tube microphones are best suited for recording sources that benefit from their warm and rich sound. Vocals, acoustic instruments, and drums are all excellent candidates for tube microphones. However, it is important to note that not all sources will benefit from a tube microphone. Sources that require a more transparent and detailed sound may be better suited for a FET microphone.
In conclusion, tube microphones are a popular choice among recording engineers for their warm and rich sound. They use a vacuum tube in their preamp stage to amplify the audio signal, delivering a sound that is often described as “musical.” While they may not be suitable for all recording situations, they are an excellent choice for recording vocals, acoustic instruments, and drums. Whether you are a professional recording engineer or a hobbyist, a tube microphone is a valuable tool to have in your recording arsenal.