Goly Porter Grinder Mastering Equalizer

The Goly Porter Grinder Mastering Equalizer features 2x4 bands of EQ with switchable HPF/LPF on the low and high end, wrapped around an MS matrix, and a master gain. Based on the highly regarded “NetEQ”, by the late Barry Porter. After many years of listening tinkering with the design, building, and listening, and adjusting, and listening, and doing custom units with various solutions -- and listening -- the only thing that remains unchanged is the parallel filter section. The in- and output sections, the high and low pass filters, the layout of the circuit, the Q circuit, and the whole implementation of it has been redesigned, and when the listening tests were done, I took a really deep dive into the details and precision of all the controls. What I have arrived at, is a very personal iteration of the circuit, with a new level of refinement. Still a Porter at its core, but also, very much a Grinder.

Please note. Goly is handbuilt in Denmark, and although this unit is setup for US power, it does not come with a US power cable. It is likely that you have an extra laying around your studio but if you don’t, then check out the Pro Co IEC Power Cable. This is the cable we grab to power gear in Front End Audio in-house studio!

Frequency Selection
41 step pot for each band, meaning you have an almost continuous flow while dialing in your frequency. The torque is adjusted to give you a stepped feel while doing more careful tuning.

Gain
+/-6dB total gain per band, on a custom 41 step pot with center tap, to obtain a perfect zero gain reference.

Q
The Q was changed from RMS to peak gain behaviour. RMS behaviour keeps the energy constant, while the peak behaviour keeps the peak level constant. Think of a balloon, if you squeeze it to make it narrower, it gets longer (higher peak, same amount of energy), but if you let a little air out, it will stay the same height as before (static peak, less energy). What is preferable comes down to temperament, but aside from the practical aspects, I found that the redesigns gave a less ringy and more intuitive behaviour, especially at more narrow settings.

High & Low Pass Filters
In the original design, the high and low pass filters were added in series with the core circuit, and they were done with a simple RC filter on an opamp. I always found them to be a bit “out of place”, when I switched them in, with the bands standing out relative to the rest of the EQ, so I nixed Porter’s HP/LP add-on, and with the help of a few relays, I tapped directly into the core of the parallel circuits. The resonance peaks on them don’t look very good on paper, but they sound amazing, and they are fully sympathetic to the other bands, when they are in action.

MS
Ms circuit, built on modern, precise, integrated circuits.

Goly Porter Grinder Mastering Equalizer Features

• 2 x 4 band EQ
• All custom designed and manufactured 41 step pots
• MS/LR switchable
• Master Gain

Goly Porter Grinder Mastering Equalizer Includes

• Goly Porter Grinder Mastering Equalizer
• Manufacturer Warranty