Helix Amplify 204 Direct 4 Channel Amplifier DSP Input Bridgeable Stereo Amp

The Helix Amplify 204 Direct (AC20410) is a compact 4-channel Class D car amplifier from the Helix Amplify 2-Series. It delivers 4 x 100 W RMS at 4 Ω, 4 x 190 W RMS at 2 Ω, or 2 x 380 W RMS bridged at 4 Ω, with DirectDSP inputs designed for use with an external DSP processor.

The Amplify 2-Series is also available as the Helix Amplify 206 DSP 6-channel amplifier with built-in 8-channel DSP.

Key specifications

• Channels: 4, fully bridgeable
• Power at 4 Ω: 4 x 100 W RMS
• Power at 2 Ω: 4 x 190 W RMS
• Bridged at 4 Ω: 2 x 380 W RMS
• Inputs: 4 x RCA (DirectDSP), 1–8 V sensitivity
• Signal-to-noise ratio: 99 dB (A-weighted)
• Operating voltage: 10.5–16 V (start-stop capable down to 6 V)
• Fuse: 2 x 30 A LP-Mini
• Dimensions (H x W x D): 40 x 248 x 114 mm

Helix Amplify: power, clarity, purpose

The Amplify series focuses on specialised models, each built for a specific application rather than trying to do everything. The result is a range where each variant delivers exactly what is needed for its intended role.

• Up to 240 W RMS at 2 Ω per channel (one channel driven) for strong dynamics
• Fully bridgeable output channels for flexible system configurations
• Very compact dimensions for space-saving installation
• Start-stop compatible down to 6 V supply voltage
• Clipping LED for quick and accurate gain adjustment
• DirectDSP input tuned for maximum signal quality when paired with a Helix DSP
• Advanced Class D topology for high efficiency and low heat output

The 2-Series forms the entry point and technical core of the Amplify platform. These compact Class D amplifiers combine strong output power, a fully bridgeable multi-channel architecture and high efficiency with straightforward installation.

Available as Direct, X-OVER or DSP variants — covering flexible 6-channel full-range setups through to dedicated mono subwoofer amplifiers — the 2-Series offers a tailored solution for most system configurations.

AMPLIFY 204: the versatile solution for full-range applications

Four fully bridgeable outputs make the Amplify 204 well suited to front-end or multi-channel setups. It works as a classic 4-channel system, a 3-channel configuration with subwoofer, or a bridged 2-channel layout, adapting to a wide range of vehicles and system requirements.

It is available as an X-OVER version with integrated active crossover, or as this Direct model optimised for pure signal transmission from an external DSP.

Sound and power above the standard

All Amplify 2-Series amplifiers offer minimal distortion, a 99 dB signal-to-noise ratio and fully bridgeable multi-channel outputs for maximum flexibility. The design prioritises application-focused performance in both sound quality and power delivery.

AMPLIFY DIRECT: made for external DSPs

The Direct models are built for DSP-based audio systems that require clean, transparent amplification. By removing conventional input filtering, the DirectDSP input keeps signal integrity throughout the signal path.

A high-quality gain stage and clipping LED allow precise level setting, while the minimal input architecture keeps noise and distortion as low as possible. A stereo/mono switch on each stereo input also enables bridged operation from a single RCA signal, removing the need for Y-adapters.

Form follows performance

The compact 40 x 248 x 114 mm footprint allows installation even in tight spaces. A removable top cover conceals all connections and controls, adding protection and a tidy finish. Matte surfaces and sharp contours allow the amplifier to sit discreetly in any modern vehicle interior.