Sontec MES-432C/9 Mastering EQ – Inward Connections SPA690 Modified

Rare Sontec MES-432C/9 stereo parametric mastering equalizer, modified by Steve Firlotte of Inward Connections.

This thing sounds amazing. I’m only selling it because I also own a Sontec 482, and plans for the second room this was intended for are now on the shelf. Bad pun intended.

This is the ±9 dB version, with fully stepped controls, three parametric bands, and dedicated low- and high-frequency shelving on each channel.

The Inward Connections modifications include:

• Six Inward Connections SPA690 discrete op-amps, three per channel
• Custom Inward Connections amplifier/output boards
• Two CineMag CMOQ-2LPC line-output transformers, one per channel

The original ITI Audio EQ/filter boards remain in the unit and are marked 1110-0945-03 and ©2008. The original op-amp connection points also remain, with the Inward circuitry connected through those locations. In other words, the original Sontec EQ and control circuitry remains, while the amplifier/output stages use the Inward Connections op-amps and CineMag transformers.

All six original discrete Sontec op-amps are included. They are untested and packed separately in protective foam. They are included for original completeness’ sake and for the possibility of future restoration by a qualified technician.

Each channel also has an additional unlabeled two-position high-shelf frequency switch next to the labeled 50/100 Hz low-shelf switch. Some documentation for the MES-432C/9 version describes the high shelf as switchable between 7 and 12 kHz, replacing the fixed 10 kHz shelf of earlier versions. The switches are not identified on this particular faceplate, but their operation on the high shelves has been confirmed.

I purchased the EQ already modified in 2019 and have used it sparingly in my professional mastering room since then. Shortly after I acquired it, Steve Firlotte replaced the bandwidth switches with new Grayhill switches.

The EQ is working well; all controls operate nicely.

Cosmetic condition reflects professional use, with visible scuffs, scratches, and front-panel wear, along with some typical Sontec bends in the rack ears that could easily be straightened if desired. It looks great racked in a console, in any case.

Included:

• Sontec MES-432C/9 equalizer
• External 115V power supply and connecting cable
• All six original discrete Sontec op-amps, packed separately

Located in St. Petersburg, Florida. Local pickup is welcome. Insured shipping will be available at the buyer’s expense after appropriate professional repacking and agreement on the shipping method.