Discrete Class A headphone amp and preamp

The Gustard H26 is a fully-balanced discrete Class-A headphone amplifier and preamp built for listeners who want control, power, and flexibility in one chassis. With a balanced signal path, matrix relay volume, dual toroidal transformers, and both headphone and preamp output modes, it fits into a desk system or a speaker chain without compromise. 

Fully-balanced discrete Class-A design

The H26 uses a fully-balanced discrete Class-A circuit with eight pairs of power transistors. Discrete components allow each stage to be tuned independently, giving the amplifier tighter control over distortion and current delivery. 

Switchable preamp and headphone modes

The headphone amplifier stage can be turned off independently, allowing the H26 to operate as a dedicated preamp. Preamp outputs can also be disabled, making it easy to move between headphone listening and a speaker chain without unplugging cables or changing connections.

Matrix relay volume control

Volume is handled by a matrix relay system designed to maintain channel balance across all levels. Instead of relying on a traditional potentiometer, the relay network keeps left and right channels aligned, reducing imbalance at low listening levels and keeping volume changes stable.

Balanced input stage with RCA compatibility

The input stage is fully-balanced, with a single-ended to balanced conversion for RCA inputs. This allows single-ended sources to benefit from the balanced architecture, improving noise rejection and signal stability as the audio moves through the amplifier.

Dedicated preamp circuitry with LME49720 op-amps

The preamp stage uses two direct-inserted LME49720 dual op-amps. These are widely used for their low noise and linear performance, helping preserve signal integrity before amplification and maintaining clarity across the frequency range.

Dual toroidal power supply design

Power is handled by two 50W custom toroidal transformers (one per channel). Separating the channels reduces interference and keeps power delivery consistent, especially during dynamic passages where both channels demand current at the same time.

Low-noise power regulation

A high-speed rectifier and Nichicon capacitor filtering stage work with a low-noise, high-current voltage regulator. This combination stabilizes the power supply and reduces background noise, supporting the amplifier’s low distortion and high signal-to-noise ratio.

High power output for a wide range of headphones

The H26 delivers up to 12,000mW at 32 ohms. It maintains strong output across higher impedances as well--7,350mW at 64 ohms and 788mW at 600 ohms--giving it the headroom needed for both low- and high-impedance headphones.

Flexible connectivity and rear panel layout

The rear panel includes RCA and XLR inputs, along with RCA and XLR preamp outputs. Balanced XLR connections are available for both input and output, making it easy to integrate with balanced DACs or powered speakers. A voltage selector, AC inlet, fuse, and power switch are all clearly laid out for easy use.

Compact desktop footprint

The H26 measures 13.0 inches wide, 10.2 inches deep, and 2.6 inches high (330 × 260 × 65 mm). The low-profile chassis fits comfortably on a desk or rack while leaving room for other components, and the included remote allows volume adjustment from a distance.

Product highlights

• Fully balanced discrete Class A amplifier
  
• Matrix relay volume control for consistent channel balance
  
• Switchable headphone amp and preamp operation
  
• Dual 50W toroidal transformers — one per channel
  
• LME49720-based preamp stage
  
• Low-noise power regulation with Nichicon capacitors
  
• Up to 12,000mW output at 32 ohms
  
• RCA and XLR inputs and outputs
  
• Remote control included

Specs

• Input
  
  • RCA x1 input sensitivity typical 2–3Vrms input impedance 4kΩ
    
  • XLR x2 input sensitivity typical 4–6Vrms max 12Vrms input impedance 8kΩ
• Preamp output
  
  • RCA output impedance 100Ω
    
  • XLR output impedance 100Ω
    
  • Frequency response: 20–80kHz / -0.1dB
    
  • SNR: >123dB
    
  • Crosstalk: <-123dB @ 1kHz
    
  • THD+N: <0.0002%
    
  • IMD: <0.0003%
    
• Headphone amp
  
  • Single-ended output (6.35mm) impedance: 0.05Ω
    
  • Balanced output (XLR 4-pin or 4.4mm) impedance: 0.1Ω
    
  • Frequency response: 20–80kHz / -0.1dB
    
  • Crosstalk: <-120dB @ 1kHz
    
  • THD+N: <0.0005% @9700mW into 32Ω load
    
  • IMD: <0.0005% @9700mW into 32Ω load
    
  • Maximum undistorted power output: 6000mW into 32Ω load
    
  • Maximum power output: 12000mW @32Ω (THD 1%)
    
• Load power per channel
  
  • 64Ω 7350mW
    
  • 150Ω 3125mW
    
  • 300Ω 1576mW
    
  • 600Ω 788mW
    
• AC power input: 100–240V manually adjusted
  
• Overall power consumption: <30W
  
• Size: 13.0 × 10.2 × 2.6 in (330 × 260 × 65 mm)
  
• Package size: 16.5 × 14.2 × 6.9 in (420 × 360 × 175 mm)
  
• Weight: 15.4 lb (7.0 kg)

What’s included

• Gustard H26 amplifier
  
• Remote control
  
• Power cable
  
• User documentation