Introducing the Bass Block V803

The Quilter Labs Bass Block V803 is a powerful and versatile bass amplifier that combines modern Class-D amplification with the warmth of vintage tube sounds.  A robust 800W output ensures exceptional performance across various speaker setups, supported by a quiet, variable-speed fan for reliable, heavy-duty use.

Quilter Bass Block V803
The Bass Block V803 provides exceptional power and tonal versatility, combining for the first time the power of modern Class-D amplification with the warmth of vintage tube amps. The proprietary Quilter Labs power section provides over 800W for full performance from any speaker, with a quiet, variable-speed fan for heavy duty use. A 3-band EQ with sweepable midrange provides “pinpoint” control of bass tone. A three position Voice switch selects “MODERN” “WARM” and “QTUBE” offering three distinct amplifier modes. In addition, flat and “scooped” inputs, FX Loop, headphone and XLR Line Out with integral cab-sim and grounding switch round out the feature set.
Quilter Bass Block V803

The Modern setting works well for clean “bottomless” bass tone especially with 2-way speakers.

The Warm setting works well for clean “bottomless” bass with a warmer coloration, especially on vintage style all-cone speaker cabs.

The Q-Tube setting works well for “heavier” bass playing when some grunge and breakup is desired, with about 10 times the power of a 50W Bassman and almost double the power of a 300W SVT head.

Quilter Bass Block V803
Quilter Bass Block V803
The rear panel offers dual Speakon™ Combo connectors for speaker compatibility, a locking AC cord for reliable power connection, and universal AC power support for use worldwide. The XLR Line Out pre-MASTER for consistent signal level regardless of where you set stage power.
Quilter Bass Block V803

Power and Performance: Delivers over 800W to handle any speaker with ease. A high-current Class-D power section that combines old-school dynamic warmth with the efficiency of modern technology.

Three Unique Amp Modes: The Voice switch provides three distinct amplifier profiles – MODERN ( same system as prior 800 and 802 models, with tight solid-state output and “bottomless” limiter). WARM (tube-type output impedance with the same bottomless limiter), and Q-TUBE (tube-type output impedance with classic tube clipping) – each delivering a unique dynamic response ranging from tight, controlled solid-state performance to lush, vintage tube warmth and overdrive.

Tone Shaping: A 3-band EQ with four controls (Bass, Midrange with sweepable frequency, and Treble) offers precise tonal adjustments.

Connectivity and Controls: Includes two high impedance inputs (Flat and Scoop), FX Loop, headphone output with cab-sim, and an XLR Line Out with integral cab-sim and grounding switch. The GAIN control adjusts drive and sensitivity, while the MASTER control matches the output power to various speaker ratings.

User Convenience: Features a MUTE-ACTIVE-PASSIVE switch with a bright LED indicator, and an FX Return that can be used as a stealth input for backing tracks. The headphone output automatically switches from FRFR on MODERN to cab-sim on WARM and Q-TUBE settings.

Quilter Bass Block V803