This plugin suite is a novelty for Acustica, as it’s completely different than any other Acqua suite. Luca Martegani, also known as Xelius, is the manufacturer of an incredible suite of hand-built audio hardware characterized by immaculate sound, quality, and value. The equalizer and compressor are the elements of this suite that impressed us most — so much so that we decided to base our new product on them. We call it Cobalt.
This project started as an exercise in reproducing a classic Altec Lansing-style feedback compressor. The whole circuit was re-designed for experimental purposes: first around a 12AT7 tube as a gain control element, then around a 12AU7, and finally, around the classic 6BZ7. The output stage was designed around a parallel push-pull of two 6SN7 GTs driving a custom-built output transformer.
We ended up with a powerful plugin that can be elegant or brutal, depending on how you use it. (That part is up to you!)
This compressor shines in tracking sessions, especially on sustained sounds such as vocals, guitars, bass, pads, and strings. And on drums and fast electronic loops, it exhibits an audible compression ranging from pumping to extreme squashing, which can be incredibly useful on certain styles of music.
The idea was to develop an old-school passive EQ around a resistive divider, using resistors, inductors, and capacitors.
The main scope of this project was to build an EQ capable of processing sound in a transparent way, preserving fast transients and without introducing too much
“coloration.” The original hardware was completely innovative, and was never mass-produced.
But this EQ is much more than simply a sampled emulation of a unique machine. Cobalt is a fully parametric, dual-channel, 5-band tube equalizer, where tubes are used all the way from the input stage to the output. It was conceived as an evolution of the classic Pultec-style design, and is the result of many years of study and research.
The LM 9736 is built around pure vacuum tube topology, including the high voltage power supply. All the components were carefully selected to optimize performance: MKP capacitors and carbon resistors are liberally employed throughout the circuitry.
The preamp section of Cobalt emulates 5 classic vacuum tube preamps. The phase and frequency response and the harmonic distortion of the original hardware are pristinely reproduced. This careful selection of preamps provides you with an array of flexible options to build your virtual console emulation.
The best use of these sound-coloring processors can only be determined by the individual user on a case-by-case basis, and on the engineer’s own ears and imagination.
