Undertone Audio

Currently unavailable. The Pyra-Sum returns March 2027.

Pyra-Sum

Passive multi-bus analog summing mixer
Pyra-Sum
Pyra-Sum front panel with instrument labels
Pyra-Sum front panel with generic labels
Pyra-Sum rear panel
Back in stock March 2027
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The Ultimate Hybrid Mixing Setup

The Pyra-Sum is a passive summing mixer that has what other summing mixers don't: multiple cascading busses. This bussing architecture allows you to truly have the sound and workflow of a large format console but with even more sonic flexibility and in a much smaller format.

We've left out any active circuitry, which means that you have total control of the coloration that's added in the makeup gain stages. It also means you'll need to use this with eight of your own preamps. Want a different sound? Swap the preamps. You could use Neve's or API's for that 70s sound. Tube RCA preamps for that 50s sound. UTA preamps for a size and musicality that has never existed before. Or, since the preamps are inserted after each stage of summing, you can mix and match: API's on the drums, UTA preamps on the music, Neve's on the vocals, etc. The sonic possibilities are endless!

Different Faceplates For Different Applications

We've made available two different faceplate styles to choose from at time of purchase. When designing what's best for your setup, the choice is yours.

Close-up of the Pyra-Sum bus switches
“It sounds great, and my workflow has become much faster and smoother.”
John Baccigaluppi, Tape Op #154
“Bottom line – this is a serious piece of studio gear despite being a single rack space unit.”
John Baccigaluppi, Tape Op #154
“…I would highly recommend it to anybody wanting to commit to getting their mixes out of the box and into the analog domain.”
John Baccigaluppi, Tape Op #154