The Sphere 900 Graphic EQ offers nine frequencies occurring in natural octave steps, that can be boosted or cut simultaneously. The rotary switches offers a visual display of the shape of the audio signal being modified.
The frequencies are 50,100,200,400,800,1600,3200,6400 and 12800Hz. The presence range of 6.4 kHz can be shifted to 8kHz or 5kHz, or (if both switches are in the on position) to 4kHz. Each frequency can be boosted to +12db or attenuated to-15db.
Duncan Rowe –
I know many famous engineers single out the 900 EQ specifically as being one of the best sounding they ever used. So when I saw a 500 series version was available, I immediately called Sphere and to my surprise the owner called me back, patiently answered all my questions, and told me these things are the real deal, same analog goodness from the 70’s. When it arrived, I immediately tracked a session through it, and wow, I’m completely blown away. I’ve never heard an EQ like this. I’ve heard engineers describe some EQ’s as “musical”, and now I finally understand why. The analog inductor magic is real, and you can hear it. The highs are really clear without being harsh. Very happy with this, will certainly be picking up some more.
“Sam Damask” Engineer