Puresound L300 Valve Preamplifier
The L300 is Puresound’s flagship valve preamplifier, designed to deliver maximum signal integrity, drive capability, and musical energy. Combining transformer coupling with a highly regulated valve power supply, it offers a refined and controlled presentation without sacrificing dynamics.
Key features:
• valve preamplifier
• dual triode gain stages (direct-coupled)
• transformer-coupled outputs
• 5 x line inputs
• 2 x RCA outputs and 2 x balanced XLR outputs
• film potentiometer volume control
• fully regulated valve power supply with 300B regulator
Design and performance:
The L300 uses two directly coupled triode stages, with the second stage loaded by a custom output transformer. This transformer steps down the signal to provide a low impedance output, ensuring compatibility with long cable runs and a wide range of power amplifiers.
Source selection is handled by a high-quality switch located close to the input sockets, minimising signal path length before the volume control and amplification stages.
Unlike passive attenuators, the L300 maintains drive and energy, avoiding the loss of impact and control often associated with high-impedance volume control designs.
Materials and construction:
• dual triode amplification stages
• custom output transformers
• high-quality film potentiometer
• valve rectified, choke-smoothed power supply
• 300B triode used as series regulator
• gas reference valve for voltage stability
• fully regulated filament supplies
The power supply is a central part of the design. A valve rectifier feeds a choke-filtered stage, followed by a regulated supply using a 300B triode as the series pass element. This ensures a stable voltage regardless of mains fluctuations or signal demand.
Sound characteristics:
• strong sense of energy and drive
• highly transparent with no added colouration
• stable and controlled across all listening levels
• excellent tonal accuracy and timbre
• consistent performance regardless of system matching
The L300 avoids excessive negative feedback, preserving natural dynamics and musical flow.
Build and usability:
The inclusion of both RCA and true balanced XLR outputs provides flexibility for integration into a wide range of systems. The low output impedance ensures consistent performance with different amplifiers and cable types.
Specifications:
• inputs: 5 x RCA
• outputs: 2 x RCA, 2 x XLR
• circuit: dual triode, direct-coupled, transformer output
• volume control: film potentiometer
• power supply: valve rectified, choke filtered, 300B regulated
Brand and design:
Puresound is a UK-based manufacturer focused on high-performance valve amplification. The L300 is designed by Guy Seargent, whose experience includes work with Audio Innovations, Voyd, Heybrook, JPW, and training in Japan with Audio Note / Kondo.
Note:
The L300 is designed for systems where maintaining signal purity, drive, and dynamic expression is critical. Proper system matching will allow it to perform at its highest level.
