Radford Electronics
Encyclopedia
Radford Electronics is a British audio manufacturer from Bristol
founded by Arthur Hedley Radford in 1946. Radford's hifi
-amplifier
s enjoyed a reputation for quality that was "second to none" especially because of its output transformers.
In 1961 the company started the STA range of amplifiers launched accompanied by the DSM pre-amplifier. The Series 3 STA25, along with other Amplifiers in the STA range, won critical acclaim. As an expert in transformer
design, Arthur Radford was able to reduce distortion by a factor of ten over the best performing amplifier of the day. The MK11 and Series 3 Amplifiers used a unique pentode phase inverter that was a joint venture between Dr A R Bailey and Arthur Radford and was the subject of a detailed article in Wireless World.
However Arthur Radford’s greatest love was for his loudspeaker
designs and the rear termination of drivers. After many years of work he eventually took out a patent in conjunction with Dr A R Bailey for the first transmission line loudspeaker. This system was the basis for all his larger designs and is still used by many well-known manufacturers.
Although today the valve audio amplifier
s attract the most attention from enthuiasts, the quality of Radford design continued into the transistor
age with the "Zero distortion" series of solid state power amplifiers produced in the mid 1970s in which THD was reduced to less than the circuit noise level. These (and later products such as the Quad 405 and Halcro range) achieved the near perfect measured performance for which designers had been striving since the earliest days of the industry. Left with no potential for objective improvements in quality, the industry started to concentrate on subjective analysis of designs and products which has, in some cases, led to a re-interest in valve amplification amongst audio enthusiasts.
At the peak Radford had four factories in Bristol England, employing 160 personnel producing metalwork, painting, printing, transformer design / production Loudspeaker assembly / test and PCB manufacture, all in house. For example another well known Radford product was the "Labpak" low voltage power supply, used in schools and colleges both in the UK and overseas.
As Arthur approached retirement the company was wound down as there was no one to take it on. After he retired in 1989 Woodside Electronics was formed by John Widgery, who had been apprenticed to Radford Electronics and was responsible for many of the classic designs. Mike Davis joined John as a partner in 1989 and they worked together to launch the CD player and update the range of valve equipment as part of the Renaissance series. Arthur died on the 21st of November 1993 and Woodside continued for a while but finally ended production in Llanbedrog, Pwllheli, North Wales in 2004.
Radford valve amplifier
s are rare today and still command high prices on the secondhand market. Much sought after and enthusiastically rebuilt, they are particularly known for classic and restrained physical design and outstanding and listenable sound quality - including a particular ability to drive, very sweetly, the notoriously difficult Quad electrostatic loudspeakers. 2006 brought hope of a rebirth for the brand, with news of plans to begin manufacture of classic valve based designs like the STA 25 Mk III in 2009.
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
founded by Arthur Hedley Radford in 1946. Radford's hifi
High fidelity
High fidelity—or hi-fi—reproduction is a term used by home stereo listeners and home audio enthusiasts to refer to high-quality reproduction of sound or images, to distinguish it from the poorer quality sound produced by inexpensive audio equipment...
-amplifier
Amplifier
Generally, an amplifier or simply amp, is a device for increasing the power of a signal.In popular use, the term usually describes an electronic amplifier, in which the input "signal" is usually a voltage or a current. In audio applications, amplifiers drive the loudspeakers used in PA systems to...
s enjoyed a reputation for quality that was "second to none" especially because of its output transformers.
History
Radford began building amplifiers in 1946, and marketed its first hifi-amplifier in 1959. Reportedly, Radford make amplifiers with such low distortion that they had to built their own test equipment to measure it; their test equipment also acquired a reputation for quality.In 1961 the company started the STA range of amplifiers launched accompanied by the DSM pre-amplifier. The Series 3 STA25, along with other Amplifiers in the STA range, won critical acclaim. As an expert in transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
design, Arthur Radford was able to reduce distortion by a factor of ten over the best performing amplifier of the day. The MK11 and Series 3 Amplifiers used a unique pentode phase inverter that was a joint venture between Dr A R Bailey and Arthur Radford and was the subject of a detailed article in Wireless World.
However Arthur Radford’s greatest love was for his loudspeaker
Loudspeaker
A loudspeaker is an electroacoustic transducer that produces sound in response to an electrical audio signal input. Non-electrical loudspeakers were developed as accessories to telephone systems, but electronic amplification by vacuum tube made loudspeakers more generally useful...
designs and the rear termination of drivers. After many years of work he eventually took out a patent in conjunction with Dr A R Bailey for the first transmission line loudspeaker. This system was the basis for all his larger designs and is still used by many well-known manufacturers.
Although today the valve audio amplifier
Valve audio amplifier
A valve audio amplifier or vacuum tube audio amplifier is a valve amplifier used for sound reinforcement, sound recording and reproduction....
s attract the most attention from enthuiasts, the quality of Radford design continued into the transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
age with the "Zero distortion" series of solid state power amplifiers produced in the mid 1970s in which THD was reduced to less than the circuit noise level. These (and later products such as the Quad 405 and Halcro range) achieved the near perfect measured performance for which designers had been striving since the earliest days of the industry. Left with no potential for objective improvements in quality, the industry started to concentrate on subjective analysis of designs and products which has, in some cases, led to a re-interest in valve amplification amongst audio enthusiasts.
At the peak Radford had four factories in Bristol England, employing 160 personnel producing metalwork, painting, printing, transformer design / production Loudspeaker assembly / test and PCB manufacture, all in house. For example another well known Radford product was the "Labpak" low voltage power supply, used in schools and colleges both in the UK and overseas.
As Arthur approached retirement the company was wound down as there was no one to take it on. After he retired in 1989 Woodside Electronics was formed by John Widgery, who had been apprenticed to Radford Electronics and was responsible for many of the classic designs. Mike Davis joined John as a partner in 1989 and they worked together to launch the CD player and update the range of valve equipment as part of the Renaissance series. Arthur died on the 21st of November 1993 and Woodside continued for a while but finally ended production in Llanbedrog, Pwllheli, North Wales in 2004.
Radford valve amplifier
Valve amplifier
A valve amplifier or tube amplifier is a type of electronic amplifier that makes use of vacuum tubes to increase the power and/or amplitude of a signal. Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers during the 1960s and...
s are rare today and still command high prices on the secondhand market. Much sought after and enthusiastically rebuilt, they are particularly known for classic and restrained physical design and outstanding and listenable sound quality - including a particular ability to drive, very sweetly, the notoriously difficult Quad electrostatic loudspeakers. 2006 brought hope of a rebirth for the brand, with news of plans to begin manufacture of classic valve based designs like the STA 25 Mk III in 2009.