Puresound P20 Phonostage
The P20 is a valve phono stage developed from the highly regarded P10, designed for listeners who want to get the most from vinyl playback while maintaining a simple, low-feedback circuit approach.
Key features:
• valve phono stage
• compatible with MM and high-output MC cartridges
• transformer-coupled output stage
• passive RIAA equalisation
• zero negative feedback design
• dual power transformer configuration
Design and performance:
The P20 uses a two-stage valve circuit based on double triodes. The first stage operates in a simple anode follower configuration, while the second stage is transformer-loaded using in-house designed output transformers. This allows the ECC88 to deliver full voltage swing cleanly to the following line stage.
The second stage is biased so that no coupling capacitor is required between the first stage and the equalisation network, helping preserve signal integrity.
RIAA equalisation is implemented using passive components, maintaining long-term accuracy and avoiding the phase shift associated with active equalisation designs.
Materials and construction:
• ECC83 input valve
• ECC88 (6922) output valve
• custom in-house output transformers
• dual independent power transformers
• passive RIAA network
Two separate power transformers are used: one for the ECC83 stage and one for the ECC88 stage. Each has its own HT (high voltage) and LT (filament) supply, reducing noise and improving stability.
Sound characteristics:
• clear, natural analogue presentation
• low background noise
• strong dynamic stability
• balanced and controlled sound
• composed handling of complex material
The absence of negative feedback and use of transformer coupling contribute to a more direct and uncoloured sound.
Build and usability:
The P20 provides sufficient output to drive any line-level input on an integrated amplifier or preamplifier. For low-output MC cartridges, a step-up transformer such as the Puresound T10 MC Step-Up Transformer is recommended.
Specifications:
• input impedance: 47kΩ
• output impedance: 4.7kΩ
• frequency response: 20Hz – 50kHz (-1dB)
• gain: 40dB
• valves: ECC83 x1, ECC88 x1
• dimensions: 360 x 310 x 100mm
• weight: 5.5kg
Note:
The P20 is designed for MM and high-output MC cartridges. Low-output MC cartridges will require a suitable step-up device for optimal performance.
