The Sphere 823 EQ is a fully discrete inductor-based equalizer module manufactured by Sphere Electronics for their Eclipse B and C consoles. This EQ has been fully serviced by Ken Hirsch of Orphan Audio/Electrodyne/Quad Eight, and is in perfect working order.
The 823 is a very unique EQ that uses a 10-position thumbwheel to select the frequency band and curve type for each of the three bands. Each band has three different selectable frequencies with at least two of the following curve types: narrow bell, wide bell, high shelf, and low shelf. The EQ also has a 10-position high-pass filter, bypass switch, and polarity switch.
The Sphere EQs are notoriously smooth and musical sounding equalizers that are sought
by recording and mastering engineers. The more well--known Sphere EQ, the 900 Series Graphic, is used by mastering engineers like Heba Kadri and others. The 823 has the same trademark sound and shares the same inductors and John Hall op amp as the 900, but is designed to behave more like a parametric EQ than a graphic, allowing three selectable frequencies per band, each with different curves.
This EQ has the more common smaller edge connector found in later Eclipse desks, and requires a +/- 24V for proper operation. The EQ will need to be racked and powered for outboard use, or can pop into an Eclipse Console for immediate use.
