Lindell Audio LiNTEC 500 Series Program Equalizer Module

Lindell Audio LiNTEC: A Solid-State Take on the Classic Program EQ

The Lindell Audio LiNTEC is a single-channel 500 Series program equalizer, built around a solid-state discrete gain stage with a custom-wound inductor. It recreates the smooth, broad tone-shaping of a classic passive program equalizer, letting engineers add air, weight, and polish to individual tracks or an entire mix from a single module slot. A program equalizer works on wide, gentle bands rather than surgical notches, which is exactly why it flatters a source instead of correcting it.

Why Solid-State Instead of Tubes

Despite drawing on a tube-era circuit heritage, the LiNTEC is 100% solid-state. Solid-state means the amplification relies on transistors rather than vacuum tubes, which run cooler and stay stable over time. That design choice delivers faster transient response, lower noise, and far tighter unit-to-unit consistency, so a matched pair tracks together with none of the drift associated with valve gear. The result keeps the creamy, musical character of the original while adding modern reliability.

The Discrete Gain Stage

At the core sits the Vintage OPA 1731, a discrete operational amplifier that gives the equalizer its punchy, forward voice. A discrete op-amp is built from individual transistors and components rather than a single integrated chip, a design prized for its headroom and character. Combined with a custom-wound inductor and custom transformers, the amplifier supplies up to 40 dB of gain to make up for the passive filter loss and to drive the transformers into pleasing harmonic territory when pushed. That makeup gain both restores level lost in the filter and becomes a tone control in its own right when driven hard.

Boost and Cut the Same Frequency

The signature trick of this style of equalizer is engaging low-frequency boost and attenuation on the same frequency simultaneously. Because the two controls act on slightly different points, the interaction sculpts a resonant shelf that fattens the fundamental while clearing muddy upper bass, the classic method for thickening kick drums and bass lines. Attenuation simply means cutting level, and pairing it with boost is what carves that hollow just above the low end so the bottom sounds big rather than boomy.

Frequency Controls

Selectable stepped frequency centers cover the low and high bands, with dedicated boost and attenuate controls and a high-frequency bandwidth control for widening or focusing the top-end lift. Bandwidth sets how wide or narrow the affected region is, so the same boost can sound like broad air or a focused sparkle. Stepped rotary pots replace continuous knobs, so every setting is repeatable session to session and matchable between two units.

Stereo Matching and Format

Each LiNTEC is hand-matched to within a quarter of a decibel, which makes pairing two units for stereo bus or mastering work straightforward. The 500 Series is a modular standard in which compact modules slot into a shared powered frame, so a LiNTEC installs in any compatible rack or lunchbox and draws power from the host. A hardware bypass removes the circuit from the path for accurate A/B comparison between processed and source signal.

In the Box

Included is a single LiNTEC 500 Series module, ready to seat in a compatible 500 Series rack or lunchbox, along with product documentation. Power and connections are provided by the host frame, so no additional supply is required. Once seated in a powered slot, the module is ready to process a track or bus immediately.

Who the LiNTEC Is for

Mixing and mastering engineers turn to program EQ when a source needs broad, flattering tone rather than surgical correction. A mastering engineer smoothing a stereo mix and a mix engineer adding sheen to vocals or heft to a bass guitar both benefit from the LiNTEC's musical curves and repeatable stepped controls. The hand-matched tolerance also suits anyone building a stereo chain, where two modules must behave identically.