The main concept of the hybrid microphone preamp was a combination of two circuit topologies – tube and transistor. The hybrid solution solved a number of technical problems, simplifying circuitry, bypassing the heap of passive elements in the sound path, which are inherent in tube equipment.

The hybrid solution made it possible to create a device with a high bandwidth => 100kHz, signal gain levels of 60 dB, and record low distortion of 0.00095% THD! The electro-vacuum tube is the core of sound amplification, with high parameters, thanks to our know-how in circuitry.
In fact, we get a device that surpasses the popular transistor preamps in terms of noise and signal distortion, but is a 100% tube device!

DEVIL’S IN THE DETAILS.

The goal of creating a preamp with the widest possible throughput and a large gain and without distortion was due to the Vacuum preamp being able to enable sound engineers to get the tone of the instrument and its character, which can be called MixReady. Since our device does not cut the spectrum of the signal, and we have a large bandwidth across the entire spectrum from 10 to => 100 kHz, leaving the accuracy of the sound source displayed in front of the microphone, and the amplification is able to catch the smallest details of the room reverb, and those spectral components below -60dB without intermodulation distortion, thereby we get better detail with minimal distortion.

Another factor that distinguishes our device from others is the use of electricity sources to supply phantom power, without using a resistive circuit, which usually tends to damp the signal between a hot and a cold signal. In our case, we have a complete separation of “hot” and “cold signals” without interacting with each other.
In our power supply implementation, the preamp has two stabilizations – in the main power supply unit and on the amplification boards. This may seem complicated, but the thoughtfulness of this detail made it possible to have a completely distributed and independent from each other system of “current circulation” and the absence of the influence of channels on each other.

ACCURACY. UNIVERSALITY. STABILITY.

Since the analysis of our personal experience is an integral part of the instrument creation process, we are free to implement certain aspects as we would like to see it in any other device. So, for example, the output attenuation knob has a discrete potentiometer, which makes it possible to precisely align this parameter without an error in the balanced output signal, thereby receiving even smaller distortions. Since simple potentiometers have an error of up to 20% of a given value, our choice was in favor of discrete potentiometers.

We can set the lamp current and the middle point of the output voltage precisely. This makes the device compatible with any 12ax7, 12at7 lamps and the only difference that will be noticeable is the gain coefficient, since each type of lamp has its own. All this leads to a minimalistic solution, without piling up all kinds of adjustable settings.

The two main controls are Gain, Volume, phase inversion, and phantom power.