DN500 — Dual Compressor/Limiter/Expander

The DN500 is a two-channel full-function dynamics processor combining compression, expansion, limiting and peak clipping in a single rack unit. It is characterised by exceptionally quiet operation, typically more than 2 dB below the noise floor of comparable products of its period, attributable to the THAT VCA topology at the heart of the signal path.

Dynamics Architecture

The compressor section offers variable-knee control from hard to soft, attack from 50 µs to 20 ms and release from 60 ms to 2 s. An auto attack/release mode handles programme material transparently. The expander section provides downward expansion with its own threshold and ratio controls. A peak limiter with variable threshold and programme-dependent release sits after the compressor, and a peak clipper tracks the limiter threshold to eliminate transient overload. Maximum output level is +21 dBu into 600 ohm.

Linking and Side-Chain

The two channels link for true stereo operation. Both the compressor and expander sections accept independent side-chain inputs, allowing frequency-conscious dynamics for de-essing or programme-dependent gating without affecting the main signal path.

Application

Broadcast loudness control, mastering-grade dynamics on programme material, FOH bus compression where transparency is non-negotiable. The combined peak clip and limiter make it a reliable insert on broadcast transmitter feeds.

Specification Highlights

• Dual-channel compressor / limiter / expander / peak clipper
• THAT VCA topology, dynamic range typically >2 dB below comparable units
• Variable knee, attack 50 µs - 20 ms, release 60 ms - 2 s
• Auto attack/release mode for transparent compression
• Independent side-chain inputs on compressor and expander
• Stereo link for true stereo operation
• Max output +21 dBu into 600 ohm, 1U rackmount