Buzz Audio MA 2.2 2 Channel Pre-amp
In order to capture the most accurate uncolored reproduction of an acoustic source, a microphone preamplifier must exhibit low distortion, wide frequency response and low noise. The preamplifier must also be capable of reproducing transient information without slew rate limiting and present a non-reactive load to the microphone itself. Many preamplifiers that attempt to achieve this specification are often referred to as sounding "clinical", however we believe the MA-2.2 brings the world one step closer to achieving this ultimate goal whilst retaining a musically warm and full sound.
As with all our mic preamplifier designs, we like to think of them as an extension to the connected microphone - not a separate entity.
The MA-2.2 has a transformerless input stage designed to minimize frequency response anomalies caused by reactive loading of the connected microphone. All gain stages utilize our own discrete transistor True Class A differential amplifiers (the BE40) to provide an amazingly wide bandwidth and fast slew rate. In fact, the internal frequency response of the MA-2.2 extends beyond 1,000,000Hz - even at full gain! (Passive filtering at the input of the MA-2.2 to limit the response to 250kHz prevents amplification of unwanted radio frequencies).
The very high speed and wide frequency response of the MA-2.2 ensures distortionless reproduction of all transients - a key factor to ensure the preamplifier does not sound clinical or cluttered in the upper midrange. The absence of the input transformer also ensures that the low frequencies are amplified smoothly, free from LF transformer distortion and phase/frequency response errors providing a "real" and tight bass sound.
Attention to the power supply design further enhances performance by providing exceptionally quiet DC power rails for the BE40 amplifier modules. The MA-2.2's ultra low noise and unobtrusive noise spectra provides the best possible dynamic range for digital recordings with most microphones contributing more noise than the MA-2.2 itself.
In order to keep the signal path as simple as possible, the MA-2.2 does not have a instrument input and the output is unbalanced, avoiding the extra stages required for these functions. As an enhancement to the overall design, we offer output transformer options to balance the output and provide some additional colour without sacrificing the key design goals of the unit.
Take a look at the channel card and also take a look at the matching MIA1.0 Direct Box adaptor.
acoustic guitar recording
* percussion and drum recording
* acoustic music styles
* string ensembles, orchestras, choirs, voice
Fully discrete hi-bias wide bandwidth differential Class A amplifiers.
Matched and selected semiconductors.
Transformerless input with hi-grade WIMA film coupling capacitors.
2 stages of power supply regulation.
Individual discrete regulators for each stage of the 2 stage amplifier.
High quality bifurcated relays for signal switching.
* No "DC servo" that messes with the bass.
Single Point Ground pcb layout.
41 position trimmed GAIN control.
Trimmed common mode noise rejection.
Output Mute and Hi/Lo input impedance switches.
Output transformer options.
2 output connectors giving access to direct out if transformers are fitted.
Rugged chassis construction.
Output Transformer Options
Both options can be supplied
factory fitted or retro-fitted in the field.
Min Gain = +16dB (-4dB with pad in)
Max Gain = +65dB
Maximum Output Level = +24dBu unbalanced.
Frequency Response = 2Hz to 250kHz @ 20dB gain (-3dB).
= 20Hz to 250kHz @ 65dB gain (-3dB).
Harmonic Distortion = less than 0.008% 100Hz to 10kHz.
Slew Rate = typically 140 V/uS, @ +20dBu output level.
EIN = -133.5dB A wtg, 150ohm source Z.
Signal to Noise Ratio = -74dBu A wtg, input shorted.
CMNR = 100Hz-80dB, 1kHz -80dB, 10kHz-70dB internal trims.
Channel to Channel Crosstalk = below noise.
Input Impedance = 3k ohms/1k2 ohms switchable.
Controls = Gain, Mute, Input Impedance, 20dB input Pad, Phase Reverse, Phantom pwr.
Indicators = Peak Level @ +18dBu, Power On.
Connectors = In-XLR3F, Out on 1/4" jack and XLR3M.
Size = 1 Unit rack mount, (482Wx44Hx300D).
Power requirements = 230V/115V selectable.