Alctron is a national brand active in the professional audio field. The first Alctron product I came across was the 500 series module. Now, Alctron's product line has become increasingly diverse, encompassing five major categories: microphones, headphones, audio amplifiers,audio tools, and audio/instrument accessories. These products cover various applications in professional audio.
The MP73EQV2 is a microphone preamp and channel strip processor featuringan amplifier with EQ, phase inverter, high-pass filter, input attenuation, and 48V phantom power. The equalizer section is the core feature, offering a 3-band inductive EQ with Shelf-type high and low bands (where the low band has selectable corner frequencies), and a Bell-type mid band with six selectable frequencies, providing 20dB of gain reduction. Additionally, it includes a separate high-pass filter with four selectable frequencies for a 3dB roll-off on low-frequency signals. While the precision of this EQ is somewhat limited, it does not hinder its use as a channel strip. Functionally, it compares favorably to the EQ built into mixing consoles.
With the EQ added, we can shape the sound according to our own ideas. I particularly enjoy the high frequencies of the MP73EQV2; its airiness above 12kHz is exceptionally outstanding, providing a vivid and silky brightness for both vocals and instruments. Next is the mid-frequency range, where sensitive qualities such as timbre, color, and harmonics can be fully expressed. For demonstration purposes, I recorded a complete version of the previous audio clip with accompaniment, where the vocals were given necessary equalization processing. To demonstrate, the entire song was recorded in one take without any post-processing, adding only reverb to blend with the accompaniment (Audio Sample 2).
From the appearance, it is not difficult to distinguish that MP73EQV2 draws on the design of the classic Neve 1073. As a classic hardware, there are similar remakes such as Heritage Audio's HA-81A. The following pictures compare the appearance of the above three pieces of hardware.
The Neve 1073 has become the most famous, widely used, and popular hardware in music recording history, thanks entirely to its "73-type microphone preamplifier" and "81-style EQ." These two components are derived from the British large console A88, which creates a powerful and robust sound that can adapt to any genre of music.
From the "73" in the model MP73EQV2, it is highly likely that it adopts the design of the "73-type microphone preamplifier." The hallmark feature of this design is that "the input and output transformers use discrete Class A design." Reviewing the product information confirmed my guess: both its output and input are equipped with independent transformers, consistent with the traditional style of the 73-type preamplifier.
Packaging, Accessories, Device Appearance, Build Quality, and Expandability
Like all rack devices, the MP73EQV2 comes without elaborate packaging. A sturdy, reliable corrugated cardboard box perfectly fulfills the packaging needs. The upper right corner of the box has an anti-counterfeiting label, allowing users to verify the authenticity of equipment.
Standard Accessories: MP73EQV2, User Manual, Warranty Card, Foam Foot Pads, and an External Power Supply.
The foam foot pads are considered as additional accessories (see the image below). If you wish to use the MP73EQV2 as a desktop device, you can affix the foot pads to the four corners of the chassis to provide some cushioning and dampening effect. The foot pads are made of high-density foam material with considerable firmness, which can support the weight of the equipment well and provide protection. The adhesive tape design makes installation convenient.
The MP73EQV2 features an all-metal chassis, providing a sturdy construction that offers a stable and reliable working environment for the internal circuitry. The front panel and side brackets are made of alloy materials, not only offering more reliable thickness but also having a smooth and delicate surface finish due to the painting treatment. The knobs and buttons on the control panel draw design elements from the Neve 1073 but have their own unique in details.
The rear panel is the interface area. It provides separate XLR (female) balanced microphone and line input ports, as well as XLR (male) balanced line output ports. In addition, there is a DI interface on the left side of the front panel. The internal circuitry adopts a discrete Class A design, which completely avoids crossover distortion and generates subtle warmth and analog tones for line or microphone signal sources.
Both the input and output interfaces are equipped with independent transformers that do not interfere with each other. It enhances the performance. See the red circle in the image below for details.
The transformer used in the original design of the Neve 1073 was designed by Rupert Neve in 1964, intended to produce balanced,subtle harmonic saturation. The 1073 is renowned for this type of saturation. Since the transformer design has always been unique to Neve, the MP73EQV2 employs a proprietary transformer and is branded with the Alctron trademark.
The mid and low frequencies of the equalizer section use concentric potentiometers (as shown in the red circle in the image below). The rear part of this control is a stepper potentiometer for selecting fixed frequency points, while the front part is a continuously adjustable potentiometer for precisely tuning the gain and attenuation values of the equalization, similar to the control method of some tube equalizers from the analog era.
The combination potentiometer on the control panel is shown in the style below. It consists of two parts: the round metal knob at the back is a stepper potentiometer, used for selecting the desired frequency points; the protruding plastic knob at the front is a continuously adjustable potentiometer, used for precisely tuning the gain and attenuation values.
In terms of overall quality, MP73EQV2 like Neve 1073, uses rotary switches, straight key switches, and precision concentric potentiometers as its main controls, ensuring high operational accuracy and durability. The stepper potentiometer for line and microphone gain adjustment is shown in the red circle in the image below.
Technical Specifications and Adjustability
Three years ago, I had the privilege of testing and using the Heritage Audio HA-81A. Now, having taken on the MP73EQV2, both of which are replicas of the Neve 1073, I will conduct a comprehensive comparison of the three models. Since complete product specifications for the Neve 1073 are unavailable, only a few key performance indicators are roughly compared here. The table below provides a more detailed display of the differences in performance and functionality between the MP73EQV2 and HA-81A replica products.
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Overall, the performance of the two amplifiers is quite comparable. The total harmonic distortion data for the MP73EQV2 lacks test signal conditions and cannot be accurately compared; it is roughly estimated to be lower than that of the HA-81A. Additionally, in terms of EQ processing capability, the MP73EQV2 does not have as much flexibility as the HA-81A, maintaining a practical level.
However, all frequency-related controls of the MP73EQV2 are configured exactly the same as those of the Neve 1073. In other words, it is a hardware replica with a high similarity to the Neve 1073. See the image below for details.
The MIC/LINE input or microphone gain can be adjusted from -20dB to +80dB. This control knob is a stepped switch potentiometer, with each step representing a 5dB unit increase in gain attenuation. Its mode of operation and adjustment precision are identical to those of the Neve 1073 and HA-81A. Additionally, the high-pass filter also retains the same control precision and frequency point settings as the Neve 1073. Meanwhile, the HA-81A employs a high-pass filter form with greater flexibility.
In terms of EQ control, the MP73EQV2 employs an identical three-band equalization to the Neve 1073, with both its control precision and frequency point settings being a complete replica of the original design. The high frequencies are fixed at 12kHz, allowing for 20dB of shelf-style gain reduction; the midrange features a bell-shaped equalizer with selectable frequency points at 360/700/1.6K/3.2K/4.8/7.2K, which are considered optimal by the original design; the low frequencies offer a shelf-style equalizer with selectable frequency points at 35/60/110/220.
Moreover, from a performance standpoint, the MP73EQV2 also has a high degree of overlap with the Neve 1073. For example, maximum output >+26dBu; total harmonic distortion ≤0.07%; equivalent input noise -125dBu, etc. From this, it can be inferred that the two are very close in performance. The only suspense lies in the impact of transformer harmonic saturation on sound signals, which we will measure in real-world use during the trial experience of the MP73EQV2's sound performance.
The MP73EQV2 draws inspiration from the control method of the Neve 1073, featuring an intuitive and clear user interface that is easy to learn, allowing for quick adjustments to achieve the desired sound. All controls have an excellent feel, providing a very satisfactory user experience. The internal circuit design is meticulously crafted with attention to detail, and the build quality is exceptional.
In this trial of the MP73EQV2, we focused on three main functions: signal amplification quality, equalization processing, and DI, to rationally understand the MP73EQV2 from a practical needs perspective. The test will use the Sennheiser MD421 Kompakt microphone to capture the audio source signal.
Test 1: Signal Amplification Quality. This evaluates the amplification characteristics, tonal color, and intrinsic noise floor of the MP73EQV2. During the test, all equalization and high-pass filters were disabled, with only the output gain set to the middle position, and the line/microphone gain control (MIC/LINE) adjusted to higher settings of 50dB and maximum 80dB, respectively, to compare the signal differences under these two processing conditions. See the figure below.
With the output gain fixed, there is an approximate. With the output gain fixed, there is an approximate difference (referenced at there is an approximate 10dB difference (referenced at 1kHz) between the signals at 50dB and 80dB. At the 50dB setting, the sound quality is quite satisfactory; although there is a slight, audible environmental noise from the microphone (the room has no acoustic treatment and average sound insulation), the captured audio source produces relatively clean sound. Switching to 80dB significantly increases the ambient noise. However, the captured audio source still yields clear, uncolored, balanced, and natural sound. No white noise-like background noise was detected throughout this process. Moreover, as shown in the figure above, there is not much change in the signal structure under these two different gain conditions, resulting in very objective and accurate spectral structures. It should be noted that the above test only replicates real-world usage scenarios and is not a true baseline noise test. Our evaluation aims to reveal the actual performance of the equipment during use.
Test 2: Equalization Processing. This test evaluates the tonal shaping capabilities of the equalizer. Tonal shaping is not only a post-mixing step; we can also design sound images or forms for individual tracks during the pre-recording phase. Common techniques include controlling the volume and texture of the sound or enhancing its transparency, among others. The figure below shows audio clips processed with different equalization settings, transforming a single sound signal into two distinct tonal colors.
Processing A enhances the low frequencies, giving the sound a thick and powerful feel; Processing B boosts the frequencies above 12kHz, adding more airiness to the sound. It also strengthens the band around 3.2kHz, enhancing the transparency of the sound.
Below is a vocal recording, with the first half being the original unprocessed sound and the second half including equalization and high-pass filtering (Audio Sample 1). The spectral comparison before and after equalization processing is shown in the figure below, where the green spectrum represents the original signal and the red spectrum represents the equalized signal.
Audio Sample 1, Alctron, 1 minute
Audio Player
With the EQ added, we can shape the sound according to our own ideas. I particularly enjoy the high frequencies of the MP73EQV2; its airiness above 12kHz is exceptionally outstanding, providing a vivid and silky brightness for both vocals and instruments. Next is the mid-frequency range, where sensitive qualities such as timbre, color, and harmonics can be fully expressed. For demonstration purposes, I recorded a complete version of the previous audio clip with accompaniment, where the vocals were given necessary equalization processing. To demonstrate, the entire song was recorded in one take without any post-processing, adding only reverb to blend with the accompaniment
(Audio Sample 2).
Audio Sample 2, Alctron, 3 minutes
Audio Player
Test 3: DI Interface Recording. This interface converts unbalanced instrument inputs into low-impedance balanced signals, which is generally used in home recording setups due to room size limitations. Typically, shorter cables are employed, eliminating the need for a DI because short-distance transmission does not cause signal loss. However, in large studios or situations requiring long-distance signal transmission, this feature must be used to avoid high-frequency signal loss.
The following test will use a synthesizer connected to the MP73EQV2 (see below), demonstrating the processing capabilities and audio
quality performance of the DI interface through an audio example.
After connecting to the DI, the synthesizer's timbre is imbued with a new color by the MP73EQV2. Without using any equalization, its sound is full of amplifier characteristics, with prominent richness and texture in the timbre, making the DI's audio quality quite satisfying. When equalization is applied, we can shape different tones. The following audio examples demonstrate drum kit sounds with different equalization settings (Audio Sample 3), as well as changes in the bass drum at different high-pass filter settings and variations in the hi-hat with continuous gain on the high-frequency shelf equalizer (Audio Sample 4).
Audio Sample 3, Alctron, 42 seconds
Audio Sample 4, Alctron, 33 seconds
Audio Player
Audio Player
If you use a pair of monitor speakers or headphones, you can easily hear the rich detail and subtle changes in the audio samples. The ]MP73EQV2 makes it easy to optimize your raw recordings without complicated adjustments.
Conclusion
The MP73EQV2 might be the most objectively accurate reproduction of the Neve 1073, not only adopting the universally recognized classic European 73-type circuitry but also fully reproducing its control method and precision. Its self-developed transformer endows the sound with delicate expression and rich detail presentation. With the elegant quality and appearance of analog equipment, the MP73EQV2 is the top choice for recording studios, production houses, and independent artists. In terms of price, the MP73EQV2 has a significant advantage. Firstly, it is a successful reproduction of the Neve 1073, priced more economically than the original device. Secondly, it focuses more on basic practicality compared to Heritage Audio's HA-81A, making it stand out in terms of cost-performance ratio. For instance, both the MP73EQV2 and the HA-81A are single-channel preamps; if used for stereo recording, two units are needed. Furthermore, for drum kit or multi-track simultaneous recording, multiple units would be required. In such cases, the MP73EQV2 offers an excellent value for money and will have stronger market competitiveness.
Advantage:
? Utilizing classic circuitry, it reproduces the pre-amplification section of the 73 class, processing signals with a rich Class A sound characteristic. Moreover, the transformer-balanced input and output preamplifier offers considerable advantages in isolation and signal protection;
? The self-developed transformer replaces Rupert Neve's design, with its rich harmonic performance being the biggest highlight of this reproduction. The sound quality stands up to any comparative scrutiny.
? The 81 class 3-band equalizer is also a key factor in shaping countless touching sounds, with an overall tonal performance that is thick, round, and musically colorful;
? Excellent craftsmanship and high practicality are evident from the shell to the internal circuitry, showcasing meticulous attention to detail. High-quality components are used throughout, ensuring solid material use without excessive decoration, thus guaranteeing reliable quality.
Ningbo Alctron Electronics Technology Co., Ltd
Add: No.76, San Cheng Road, Xiu Feng Industry Area,Gaoqiao Town, Ningbo China.
E-mail: sales@alctron-audio.com
Tel: +86 574 88011699
Fax:+86 574 87157176
Post code: 315191
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