In the world of high-fidelity audio there are devices that are not created only to reproduce music, but to tell a story. Pyrus is one of these. A single-ended tube amplifier that has its roots in the pioneering era of electronics, when the pear-shaped tubes of the 1920s represented the pinnacle of available technology, combining formal elegance, circuit simplicity, and a musicality that is difficult to replicate today. This project was born from the desire to bring back that way of understanding audio, made of few watts, high sensitivity, and a surprisingly human sound.
Imagine a beautiful blonde girl, with a bright smile and a juicy pear in her hands. This image represents our passion for the old pear-shaped tubes of the 1920s, symbols of an era in which elegance and functionality merged naturally. From this suggestion takes shape Pyrus, a tube amplifier that does not chase numbers or modern trends, but celebrates the timeless beauty of historic tubes and the magic of pure, direct sound, free of artifices.
Pyrus: The Amplifier That Tells a Story
Pyrus is the natural evolution of the Pollitos project, based on the famous 71A tube. Also in this case, the project was commissioned by the same passionate customer, deeply fascinated by very low-power amplifiers and pre-war era tubes. The goal was not simply to “make another amplifier”, but to go even further back in time, exploring the sonic character of the 46 tube, a true icon of the first generation of power tubes.
Pyrus is designed for those who listen carefully, for those who own high-efficiency loudspeakers, and for those who understand that a well-designed watt can deliver more emotion than dozens of anonymous watts. It is an amplifier that invites you to slow down, to listen, to rediscover the three-dimensionality of the soundstage and the tonal naturalness that only the most essential circuits can offer.
The 46 tube, a forgotten protagonist of 1930s audio
The 46 tube was introduced in the United States in 1933 and is one of the most interesting and unconventional audio tubes of its era. It is a dual-grid tube designed with remarkable versatility, to the point that the original datasheet describes different applications. It can operate in class B with the two grids connected together, or in class A using the outer grid connected to the anode, a solution that was far from common even by the standards of the time.
It is no coincidence that designers of the 1930s considered it an “advanced” tube. As early as 1933 it was used in the Silvertone 1654 receiver, a unit with as many as 12 tubes that employed three 46s in the audio stage, according to a configuration suggested directly by the manufacturer, with one 46 in class A as a driver feeding a pair in class B. From a construction standpoint, the 46 is equally fascinating. The filament is a ribbon type with oxide coating, the grids are supported by copper structures to improve heat dissipation, and when observed from above through the top mica, the filament loops and the orderly geometry of the grids are clearly visible, with wires perfectly parallel to the plate. The large classic bulb, with a diameter of about 51 mm and a height of 118 mm excluding the UX5 base pins, helps make it a true icon of 1930s pear-shaped tubes. Despite its limited power, the 46 has gone down in history for its linearity, sonic refinement, and an extremely modern design approach for its time, qualities that today make it a sought-after and fascinating choice in the most purist single-ended projects.
Technical Features
- Output tubes: 46, historic directly heated tubes, appreciated for their linearity and musicality
- Driver: 27, chosen for its tonal coherence and driving capability in minimalist configurations
- Output power: about 1.2 watts RMS per channel, optimized for high-sensitivity loudspeakers
- Output transformers: SE6K4-46, designed specifically for the 46 tube and for very high-quality single-ended applications
The design philosophy of Pyrus is clear: simple circuitry, carefully selected components, and maximum attention to sound quality. It is not an amplifier that seeks impact or spectacle, but one that focuses entirely on naturalness, microdynamics, and the ability to convey the breath of the music. Every choice was made to respect the character of the tubes used and to enhance their intrinsic qualities.
For DIY Enthusiasts
Pyrus is also a project dedicated to those who love to build, understand, and get their hands inside equipment. For DIY enthusiasts, a complete set is available, designed to ensure electrical consistency, safety, and sonic performance in line with the original project.
The set includes:
- Detailed schematic
- 1 dedicated power transformer
- 2 SE6K4-46 output transformers
- 1 filter choke
Pyrus is not just a tube amplifier, but a true tribute to the history of audio. A homage to the pear-shaped tubes of the 1920s and to a way of designing based on essentiality and technical competence. It is a project that speaks to those seeking authenticity, to those who appreciate tradition, and to those who want to listen to music as it should be: alive, present, and emotionally engaging. If you would like to be part of this story, contact us for more information about the project and the available components.