Passive Power,
Classic Character

The most unique passive equalizer ever made joins the ever-expanding lineup of processors that make up the Virtual Mix Rack ecosystem.

Play Video PLAY


The SD-PE1 provides a realistic reproduction of a classic passive EQ while also providing unique features only possible through digital emulation and modeling.

Toggle the ‘Tube’ Stage

A natural side effect of passive EQs is that the audio coming out of them will always be significantly quieter than the audio going in. To combat this, the original hardware featured a tube amplifier stage after the EQ. We’ve made it possible to turn this stage on and off, which means you can remove those saturation and color effects from the processed signal without a drop in output level.

More Flexible Frequencies

Extra Tone-Shaping Tools

On the original hardware model, frequency selection for processing was limited to what was presented on the front of the hardware. However, in addition to adding extra frequencies to each band, we’ve also made selection both stepped and incremental. It’s a tinkerer’s paradise!

A Piece of Production History

Now Part of The Legendary Virtual Mix Rack

The piece of hardware that directly inspired this plugin has been a studio staple since it was first introduced in the early 1960s. Its addition to Virtual Mix Rack’s ever-expanding plugin ecosystem brings even more historic analog processing power and color right to your DAW.

Play Video PLAY

Hear the SD-PE1

What Are The Pros Saying?


"Staying true to tradition, the SD-PE1 introduces something new to the classic hardware without sacrificing its original sonic character. Highly impressed—I’m a fan!"


Emmy-nominated, Platinum Mix Engineer
Rihanna, Coldplay, Justin Bieber


“The SD-PE1 adds weight to my kicks and snap to my snares that I always listen for with this style of EQ. Having the ability to dial in the exact frequency with the SD-PE1 makes it 
even better.”


Producer, Engineer
Ne-Yo, Glorilla, Kenny Mason


“I love the added frequencies of the SD-PE1. It helps get my kicks fat and punchy, and my vocal top-end becomes brilliant, but not harsh. Slate Digital has taken another classic unit and made it better!”


Mix & Mastering Engineer, Producer
Rick Beato, NeedToBreathe, Fozzy


“This unit always had its ‘thing’ —simply turn it on, and you could hear it straight away. The SD-PE1 sounds just like the original. I’m diggin’ it!”


Collective Soul, Sevendust, Organized Noize


“It reminds me of the real one: the low-end boost & cut interact as expected, and the high end is especially nice. I love an EQ with a high-end attenuation control.”


Founder, Mountain Road Records


“Slate Digital continues to impress with the SD-PE1. It's smooth and tight in the low end, with very open and warm mids & highs. It has the same signature vibe as the original hardware when aggressively boosting, adding a big punch to snares and great upper mid-range energy to electric guitars. The extended high end and sweepable frequencies are also a useful, modern touch. I am loving this addition to the VMR lineup!”


Grammy nominated Engineer, Mixer, Producer
Bruce Springsteen, Shania Twain, John Mayer

previous arrow
next arrow

How it works

Hover over highlighted sections
to learn more about the interface:

passive EQ plugin interface by Slate Digital
Tube Switch: When disabled, the natural saturation and color effects of the plugin’s traditional tube amp stage are removed from the signal without a drop in output level.
High Shelf: This is a shelf EQ band with a fixed slope. It can only be attenuated, using the ‘C’ control. In addition to the original hardware’s frequency selection, we’ve added two more for you to choose from: 3kHz at the bottom, 30kHz at the top.
High Shelf Attenuation: This knob is responsible for attenuating the top-end shelf band.
High Bell: This is a bell-shaped band with an adjustable ‘Q’ (control F). In contrast with the high shelf, this band can only be boosted (control E). We also added two additional frequencies to this control (1kHz and 2kHz), modeled after a later iteration of the original hardware.
High Bell Boost: This knob is responsible for boosting the top-end bell band.
High Bell ‘Q’ Control: This knob adjusts the breadth or narrowness of the high bell band.
Low Shelf Attenuation: This knob is responsible for attenuating the low-end shelf band.
Low Shelf: Like the High Shelf, this is another shelf EQ band with a fixed slope. We’ve again added two additional processing frequencies to the original hardware’s specs, at 40Hz and 70Hz.
Low Shelf Boost: This knob is responsible for attenuating the low-end shelf band. 


Developing The SD-PE1

Mickaël Albisser, Audio DSP Engineer for Slate Digital, discusses how he and his team developed the SD-PE1 –The latest vintage equalizer emulation that is now part of Slate Digital’s Virtual Mix Rack.

SD-PE1 Walkthrough

Chad Carrier, VP of Products at Slate Digital walks us through the details and features of the new SD-PE1, a faithful reproduction of a classic passive EQ.

Features & Specs


  • Passive program equalizer
  • Digitally modeled from legendary outboard unit
  • Additional frequencies for deeper processing
  • Stepped and incremental frequency selection
  • Toggle traditional tube-stage saturation on/off
  • Perfect for drums, bass, vocals, and mix bus
  • Available now in Virtual Mix Rack for All Access Pass and Complete Access subscribers
  • Also available as an individual module in VMR with a perpetual license


  • Software Type: Passive Program Equalizer Emulation
  • Plugin Architecture: 64-bit
  • Format: VST2, VST3, AU, AAX
  • Hardware Requirements, Mac:
    Intel or Apple Silicon Processor
  • Hardware Requirements, PC:
    Intel or AMD Processor, 4GB RAM
  • OS Requirements, Mac:
    macOS 10.15 or later (macOS 11 or later rec.)
  • OS Requirements, PC:
    Windows 10 or 11


iLok USB dongle required


Perpetual License