This week centers on dynamics and equalization: a boutique germanium compressor emulation developed alongside the engineer who owns the original hardware, two reference passive tube EQs from Softube, a Luca Pretolesi collaboration from Acustica Audio, and an indie mastering processor from Japan with a genuinely different approach to EQ.
P252 MDN Diode, Pulsar Modular
$165
Rupert Neve's earliest compressor designs used germanium diodes before silicon became the standard. The 2252, built in 1968, had a short production run, and very few units survived. Marc Daniel Nelson, a Grammy-nominated engineer, purchased one from a former technician at Wessex Studios in London, the room where The Clash, the Sex Pistols, the Pretenders, and Queen recorded albums through the 1970s and 80s.
Pulsar Modular spent nearly two years developing P252 MDN Diode with Nelson, working from that specific unit. The feedback topology routes the compressor's output back into its own detector, causing the signal path, feedback loop, detector, diode stage, and timing circuits to interact as a system. That interaction is what makes the 2252 unusual: modelling the components in isolation would miss how they respond to each other under signal.
The hardware has no adjustable attack. The circuit sets it. Release is fixed at 40ms on the original unit, extended to a range up to 400ms in the plugin. When pushed hard, peak meters read higher than the dry signal because transient energy passes through before the detector catches it. That behavior, which made the 2252 difficult to use in the 1970s, is why it ended up on punk records.
Available for Windows and macOS in VST3, AU, and AAX formats. A 15-day trial is available.
Reference 1956 and Reference 1998 Equalizers, Softube
$79 each / $89 bundle
Softube released two passive tube EQ emulations this week, using year-based names rather than identifying the original hardware. The Reference 1956 is built from a design that has been in continuous studio use for over 70 years. Its minimum-phase passive character favors broad tonal moves over narrow surgical cuts. Softube added mid/side processing and a Headroom control to emphasize the thick transformer low end, two features the original hardware lacked.
The Reference 1998 is a four-band passive parallel design with a tube output stage. The shelving filters move from wide and smooth at conservative settings to a more colored shape when pushed. The tube stage adds headroom without forcing saturation: there is room to ride the signal before it breaks up.
Both plugins integrate with Softube's existing Equalizers platform, which layers modern parametric processing and visualization over vintage character. If you already own Equalizers, the bundle extends that system. If you want the vintage units without the platform, both are available standalone.
The plugins are sold at an introductory price through the launch period. Available for Windows and macOS in VST, VST3, AU, and AAX formats.
Get Reference Equalizers Bundle →
Diamond Color EQ4, Acustica Audio
$99 intro (regular $199, intro ends September 9)
Acustica Audio builds plugins using a convolution-based sampling approach they call NOVA Hybrid Technology: the analog hardware's behavior is captured at the component level rather than approximated by a circuit model. Diamond Color EQ4 was developed in collaboration with Luca Pretolesi of Studio DMI in Las Vegas, whose mastering credits span electronic music releases across the past two decades.
The EQ has four bands chosen for musical response rather than surgical flexibility, plus high and low-pass filters. Mid/side mode is built in. A sampled PRE stage captures the analog input path of the original hardware and runs before the EQ bands, contributing what Acustica describes as color: harmonic content that sits alongside frequency correction.
The intro price of $99 is half the regular price and runs until September 9. Available for Windows and macOS in VST3, AU, and AAX formats.
REISEI, ONRI Audio
$399
ONRI Audio is a small Japanese developer with one product: a mastering processor that keeps every relevant control visible on a single screen. REISEI integrates spectrum analysis, EQ, compression, saturation, stereo imaging, and limiting without requiring tab navigation.
The distinctive feature is PARTIAL mode, a harmonic-tracking EQ that works differently from conventional bands. It identifies individual harmonics in the source signal and follows them as pitch changes during playback. You can lift, reduce, or invert specific partials as they move. The processing is strictly linear, so no distortion is introduced as a side effect of the EQ operation. The spectrum analyzer doubles as the control surface: every band, node, and grip is manipulated directly on the display rather than through a separate panel.
The signal chain is reorderable. Compressor, saturator, EQ, and dynamic EQ can be placed in any sequence depending on what the material needs. A UNITY control provides level-matched bypass for comparison without gain differences skewing perception. Loudness metering follows ITU-R BS.1770-4, with presets for major streaming targets.
REISEI is macOS only at launch. Intel Macs are not supported. A Windows version is planned. A 14-day trial is available from the developer's website. Three activations are included with purchase.