Puresound A30R Integrated Valve Amplifier
The A30R is a Class A integrated valve amplifier designed to deliver strong performance across a wide range of loudspeakers. Using a push-pull 6550 output stage, it combines power, clarity, and reliability in a straightforward, well-executed design.
Key features:
• integrated valve amplifier
• Class A operation
• 6550 (KT88-type) output valves
• ultra-linear push-pull output stage
• 30W per channel
• 3 line inputs
• ALPS “Blue Velvet” motorised volume control
• remote control operation
• selectable 4Ω / 8Ω outputs
• triode mode switch
Design and performance:
The A30R operates fully in Class A up to its rated output, avoiding the crossover distortion associated with Class AB designs. This results in a more consistent and natural sound across all listening levels.
The output stage uses Electro-Harmonix 6550 valves in an ultra-linear push-pull configuration, delivering a balance of power and clarity. A switchable triode mode is also available, reducing output power but increasing linearity, which can be beneficial with more sensitive loudspeakers.
An auto-bias system simplifies maintenance, allowing output valves to be replaced without manual adjustment.
Materials and construction:
• Electro-Harmonix 6550 output valves
• twin valve rectifiers
• choke-smoothed power supply
• twin power transformers
• SCR polypropylene capacitors
• selected carbon film resistors
• wide bandwidth output transformers
The power supply uses valve rectification and choke smoothing to reduce noise and maintain low impedance, while the output transformers are designed for extended bandwidth and strong low-frequency control.
Sound characteristics:
• clean, stable Class A presentation
• strong bass control and extension
• clear and open midrange
• consistent tonal balance at all levels
• good scale and dynamic capability
The A30R is designed to offer the benefits of valve amplification without the limitations of low-powered SET designs.
Build and usability:
The amplifier includes a motorised ALPS volume control with remote operation, along with multiple inputs for system flexibility. It can also be used as a power amplifier by setting the volume to maximum.
Specifications:
• power output: 30W per channel (Class A)
• output valves: 6550 (push-pull)
• inputs: 3 x RCA
• speaker outputs: 4Ω / 8Ω
• operation modes: ultra-linear / triode
• bias: auto-bias
Brand and design:
Puresound is a UK-based manufacturer focused on high-performance valve amplification. The amplifier is designed by Guy Seargent, whose experience includes Audio Innovations, Voyd, Heybrook, JPW, and training in Japan with Audio Note / Kondo.
Note:
The A30R is well suited to loudspeakers in the 86dB or more sensitivity range, offering a strong balance of power and refinement without the need for highly efficient designs.
