Tascam initiatives for high-quality mic preamps
All of our products are tested and adjusted repeatedly to ensure the high sound quality Tascam is known for. Therefore, adjusting constants and using thin-film resistors, or filters to reduce power supply noise and other interference are just some of the many know-how skills we have taken to improve the distortion rate and signal-to-noise values.
Today, we have three different circuit architectures implemented in our products.
HDIA (High Definition Instrumentation Architecture)
Type: Instrumentation Amplifier
HDIA has an instrumentation amplifier with ultra-low noise characteristics employed in the first stage of the microphone amplifier section, delivering excellence in EIN, S/N ratio, distortion ratio, and overall frequency response. This architecture provides a generous gain range and acoustic characteristics are maintained even when the gain is increased.
Ultra HDDA (High Definition Discrete Architecture)
Using discrete components, a Darlington circuit and a constant-current power supply circuit is adopted in the first stage of the microphone amplifier. This architecture allows the input signals to be less affected by the impedance fluctuation of the power supply and offers a wide gain range with improved CMRR and S/N ratio.
HDDA (High Definition Discrete Architecture)
The first stage of the microphone amplifier is composed of discrete components and employs carefully selected transistors that achieve EIN improvements.
Terms and Definitions
EIN (Equivalent Input Noise)
EIN is the value of the noise generated inside the amplifier that will be added to the input signals.
Substantially, this represents the smallest signal level the unit can handle and is one of the most important parameters used for expressing the performance of audio equipment such as microphone preamplifiers, for example.
S/N (Signal-to-Noise) Ratio
The S/N ratio is another important parameter that expresses the performance of audio equipment. It compares the signal level to the amount of noise that comes with it. The higher the value (greater than 0 dB), the less noise is obtained.
The frequency response is often shown in graphs or numbers and indicates the acoustic frequency bandwidth the equipment can handle. In a graph, the ideal frequency response is shown as a line that goes straight from low to high frequencies and represents a more natural and crispy clean sound. In numbers for example, between “20 Hz to 20 kHz, ±6 dB” and “20 Hz to 20 kHz, ±1 dB” the latter is the closest to this ideal.
CMRR (Common-Mode Rejection Ratio)
CMRR is the measure of the ability to reject or suppress input noise components in balanced input amplifiers and other equipment using differential amplifiers. The higher its CMRR, the better an audio product performs in environments with high electromagnetic interference.