Oracle Summing Mixer - music gear review

Music Gear Review: Oracle Summing Mixer

Engineer/producer Greg Wurth offers his Oracle Summing Mixer. This is a 16-channel analog summing system that uses Steve Firlotte’s highly touted VF600 discrete amplifier blocks and four Cinemag CMOB-3L transformers. It comes in a 2U all-steel cabinet with separate power supply and connecting cable. Internal construction is top-notch with all of the 20 VF600’s held down in their sockets by long metal straps.

The Oracle has 16 line inputs via two DB25 connectors. There are inserts for each pair of stereo stems (8 total) with lighted, front panel hardwired bypass switches.

In my testing, I liked the luxury of selecting either hardwired mono or full stereo stems at the touch of a lighted front panel button. Another big “plus” I’ve not seen on any of the other summing systems I’ve reviewed so far are the two separate stereo bus insert paths with lighted, front panel In/Out buttons. You may audition two completely different processing chains easily.

To check the stereo output bus level are a pair of large vintage-looking Sifam AL20 VU meters with a large control knob to set the final output level easily. It is placed last, after the stereo insert points, so any change here does not affect the threshold settings of your proceeding inserted stereo bus compressor/limiter.

On the rear panel, the Oracle Summing Mixer finishes with two sets of XLR output connectors—identical stereo line level outputs—one could go directly to an analog recorder or analog-to-digital converter input and the other pair could go to your monitor controller.

I found the Oracle to do everything I wanted when summing “out of the box.” Compared to my “in the box” mixes, the Oracle changes the whole mix “picture” to analog sounding with a full and rich sound stage.

I am able to retain my Pro Tools mixing process, only it now sounds stereophonically wider, has more dynamic range and is much more transparent! The Oracle Summing Mixer sells for $4,395 MSRP.


Barry Rudolph is a recording engineer/mixer who has worked on over 30 gold and platinum records. He has recorded and/or mixed Lynyrd Skynyrd, Hall & Oates, Pat Benatar, Rod Stewart, the Corrs, and more. Barry has his own futuristic music mixing facility and loves teaching audio engineering at Musician’s Institute, Hollywood, CA. He is a lifetime Grammy-voting member of NARAS and a contributing editor for Mix Magazine. barryrudolph.com