The Lumin Sonic Enhancer is a work-alike of the BBE Sonic Stomp, the single-channel stompbox version of the rackmounted Sonic Maximizer 482i / 882i, first released in the late 1980s.
The sound is often described as like taking a blanket off your speaker. It adds clarity and definition to your tone and can be adjusted to suit a wide variety of rigs and settings.
The original unit uses a proprietary analog IC manufactured by New Japan Radio that contains the core of the circuit. The Lumin is a reverse-engineered expansion of the circuit on that chip, but it should be stressed that it is not a clone, because the chip implementation is patented. A midrange knob has been added along with switches to set the frequencies of the Process and Contour knobs.
The Lumin works equally well for electric guitar, acoustic guitar, and bass guitar, but the default configuration in the parts list is best suited for electric and acoustic guitar.
The Lumin project is a workalike of the BBE® Sonic Stomp / Sonic Maximizer. It’s based on work done by Bajaman (documented on FSB) and Sebastian Montti (stm) on DIYStompboxes in recreating the functionality of BBE’s proprietary NJM2150AD chip.
The BBE 482i Sonic Maximizer rack unit first appeared on the scene in the late 1980s and quickly achieved legendary status among sound engineers for the way it imparted clarity on the signal—often described as sounding like a blanket was lifted off the speaker cabinet. The circuit is said to create “frequency-dependent time alignment” so that the audio frequencies hit the speaker in a more optimal way. Many professional audio setups even outside the music industry utilize the “BBE process” to enhance sound quality.
The later Sonic Stomp is a stompbox version of the rack unit that was originally released in the late 1990s or early 2000s. The circuit itself is identical to the single-channel rack unit, but intended for use with guitar or bass.
Both the Sonic Stomp and the Sonic Maximizer use a specialized chip, a NJM2150AD, which was designed by BBE and manufactured by JRC/NJR. The datasheet for this chip is readily available, although the chip itself can only be obtained from BBE—but the datasheet tells enough of the story that the circuit can be easily replicated with a relatively small number of components.
The NJM2150AD is a nearly-complete analog circuit composed of opamps, resistors and capacitors all put onto one chip, ostensibly to keep their secrets (sort of like a very expensive version of gooping)—but it certainly didn’t hurt their manufacturing costs either.
The circuit itself is a state variable filter, which splits the signal into three parts (low pass, bandpass and high pass), applies a treatment to each of the frequencies, and mixes them back together. The original unit provided knobs to control the low and high portions of the signal. It’s extremely easy to add a control to the bandpass path for frequency adjustment of the midrange, and the Lumin project incorporates this modification.