When it’s time to set up your studio, a microphone is one of the center pieces of equipment you will need. As you search for different types of microphones, you come across a category named “tube microphones.” The tube mics are a particular breed of microphones. They are different from other microphones in many ways. Their primary specification is that they use vacuum tubes as their impedance converter. If you are looking for that distinctive and warm sound to record in your studio, then a tube mic might just be what you need. Tube mics have complex features as compared to other microphones, and this makes them more expensive. However, with a variety of tube mics in the market, it can be quite a challenge to find a mic that works best with your voice (or any voice that you plan to record).
What Is a Tube Microphone?
Let us discuss the basics first. A tube microphone is a microphone that has a vacuum tube inside it. The vacuum tube amplifies the microphone’s signal. The condenser capsules in the microphone enable the microphone to be sensitive to low sounds, capture details, and pass response faster. When the audio signal in the condenser capsule has low amplitude, the tube will bring a balance with high impedance. The tube will amplify the audio signal and lower the impedance. The vacuum tube enables the signal to travel within the mic’s circuit. Then, it will become audible through the output connection. Without the amplification, the audio coming out will be just a bunch of noise covered in interference.
The amplification takes place inside the microphone, and for the vacuum tubes to function, they need power. That is why the tube mics have an external power supply because the power required is high (much higher than what your audio interface or pre amp can provide). Throughout the process of signal amplification, the tube mic will be receiving power from the external power supply. The moment you disconnect it from the power, the whole process comes to a halt. Several other features make the tube mic special, such as:
- The components are hand made by assembling wires to ensure its sound is effective and reliable
- It has tonal variants that enable the vocals to sound brighter
- Has a singular tone characteristic brought about by the valve compression
How Does a Tube Mic Work?
A tube mic is a large diaphragm condenser that uses its vacuum tubes as an impedance converter. The signal passes through the capsule condenser, then the vacuum tube picks that signal up and amplifies it before the signal travels through the mic’s circuit. You will then receive the signal output, and the output will be clear with no interferences.
For your tube mic to work effectively, you need to master the setting, which is complex compared to setting other microphones. Let us get to see how you should set your tube mic:
- Correctly mount your microphone to the microphone stand (Tube mics are quite heavy so make sure you have a strong an quality stand)
- Connect your microphone to the power supply using the power cable
- Connect the audio output cable to the microphone’s input cable
- Turn the power socket on
- This is where many people make a mistake. You need to give the mic time to warm, approximately 20 minutes. A warm tube means that the sound is being amplified nicely and the signal will be strong, clear, and with minimum noise.
Taking good care of the mic is something that you need to get used to. Remember, you’ve spent a nice chunk of money buying this piece, so keeping it in a safe and dry place is imperative to maintain the quality of the components, and especially the tube itself. When you finish recording, dismantle the tube mic with the following procedure:
- Turn off power
- Remove the mic’s power cable from the power supply
- Disconnect the mic input cable with the audio output cable
- Remove the mic from the mic stand
- Give your microphone time to cool to avoid damage to the tubes
- Carefully place your mic in its storage case
Parts of a Tube Mic
A tube microphone has five parts that make up the whole system. All five parts play a significant role in bringing out the desired sound. Let’s check out each part and how it functions.
1. Condenser Capsule
This is the transducer component of the microphone. The condenser capsule has two parts, the backplate, and the front plate. The backplate is stationary, whereas the front plate is movable, and it acts as the diaphragm. Its principal function is to convert sound signals into audio signals through electronic principles.
2. Vacuum Tube
The vacuum tube has three electrodes that enable it to function as an impedance converter and an amplifier. The vacuum tube amplifies the audio signal and lowers the impedance, creating an impedance that the mic’s circuitry can handle. The vacuum tube is found inside the microphone’s body so that the amplification can happen close to the capsule since the sound signal in the capsule is small.
3. Power Supply Unit
Vacuum tubes are active electronic devices, and they require electrical energy to function. Therefore, for the effectiveness of the microphone, it needs an external power supply unit that will constantly supply the needed energy. The microphone cable should remain connected to the power supply throughout the recording session.
4. Internal Circuitry
The tube mic has other electric components other than the vacuum tube. The internal circuitry contains stages that ensure the output is not distorted, thus preventing overloading the microphone output system. It also protects the internal of the mic by ensuring proper electrical flow.
5. Output Transformer
This device allows the conversion of audio input into an output signal. The output transformer, which is a core part of the tube condenser, also removes the audio signal’s impedance. It serves to protect the audio signal so that it doesn’t pick any noise interferences as it moves to the microphone preamp.
At the end of the day, what really makes Tube microphones special is their warm sound. What makes a microphone much more expensive than the next one is really the quality of components, and mainly that tube that gives the sound its magical sound. So when you are looking to spend your hard-earned money on that gorgeous microphone, make sure you are picking the microphone that really sounds the best with your voice. Choosing that right microphone is the first step in producing quality music.
Spend some time to test and listen to the sound of as many microphones as you possibly can. Only one microphone will have the privilege to call your mics cabinet its new home. So you better make the right choice.
At Mello Studio, we love talking to people about microphones! And we have quite a number of them here in our online store. We have hand picked the brands that we represent, and we stand behind these names when it comes to quality of sound.