Boutique, stepped, and stubbornly analogue
The Porter Grinder is a Danish built, hand made mastering equaliser descended directly from the late Barry Porter's legendary "NetEQ" - a design that spent years as an insider's secret among a small number of mastering rooms before GOLY took it apart and rebuilt it around modern precision parts. The one in our rack is an original generation build: 2x4 bands, everything switched, nothing automated, no menus, no recall, no compromise. Units are made to order in tiny numbers with lead times measured in months, and the switch banks alone cost more than most complete pieces of outboard.
What GOLY actually changed
The only part of Porter's original circuit left untouched is the parallel filter section - the reason the EQ behaves the way it does. Everything around it was redesigned: new input and output stages, reworked shelving filters, revised high and low pass filters, a new Q circuit, a fresh board layout, an added M/S section, and a master gain stage that behaves like a full-range fifth band. The result is still a Porter at heart, but a considerably more precise and better behaved instrument than the originals.
Why it is a parallel EQ, and why that matters
Most equalisers place their filters in series, so each band interacts with the last and phase error stacks up as you use more of them. The Porter's filters sit in parallel across a common bus, so the bands do not fight one another and the summed result stays coherent even with several bands working at once. That is why the unit can sound almost invisible on first listen - the tonal change arrives without the usual smearing, ringing or midrange congestion that gives most analogue EQs away. Bypass it after a few small moves and the character becomes obvious.
The switches - and why the originals matter
Every control on our unit is a 23-position Blore-Edwards switch: military grade, gold-contact, discrete resistor stepped switching for both gain and frequency. Gain moves in 0.5 dB steps to a maximum of 5.5 dB of cut or boost per band, and channels are matched to better than 1% relative tolerance, so left/right and mid/side tracking is genuinely exact rather than approximately exact. A setting written down today returns identically in a year - which is the whole point for album sequencing and for revisions that land months after delivery.
That is also the distinction worth understanding: later and current generation Porter Grinder builds move away from full discrete resistor switch banks toward potentiometer based controls. Pots are cheaper, faster to build and infinitely variable, but they cannot guarantee stepped repeatability or matched stereo tracking to the same tolerance, and the tonal grain of a resistor ladder is not the same as a wiper on a carbon track. Ours is the switched original - the version people specifically go looking for on the used market and rarely find.
Controls and topology
Four bands per channel. Six Q settings on each mid band, five on each low and high band, with shelving modes selected from the Q switch rather than a separate control. Switchable L-R / M-S operation across the whole unit, split master gain for both modes, per-band bypass and a global bypass for honest comparison. High and low pass filters sit at the edges of the audio band to tidy the extremes without touching the musical range.
How we use it
The Porter Grinder is one of several equalisers in our chain, and which one gets used - and where in the signal path - is a decision made per record, by ear, against the monitoring. Broadly, this is the unit we reach for when a master needs density and authority rather than correction: weight in the lower midrange that stays defined, top end that opens without becoming glassy, and stereo moves in M/S that hold together instead of hollowing out the centre. It is not a repair tool. It is a finishing tool, and it is used in small amounts.
Hardware info
Hand built to order in Denmark, 3U, dual channel, priced in the same territory as a small car and effectively unobtainable second-hand in switched form. One of the rarest pieces in the building.
Hear it on your record
Book a master
This chain is available on every stereo and stem master we deliver from Manchester.