The EF86[1] is a high transconductance sharp cutoff pentode vacuum tube with Noval (B9A) base for audio-frequency applications.
It was introduced by the Mullard company in 1953 [2] and was produced by Philips, Mullard, Telefunken, Valvo, and GEC among others. It is very similar electrically to the octal base EF37A and the Rimlock base EF40. Unlike many pentodes, it was designed specifically for audio applications, with low noise and low microphony claimed advantages, although a rubber-mounted vibration-resistant base was still recommended.[2] It has a much higher stage gain than any triode, which makes it susceptible to microphony. The EF86 was used in many preamplifier designs during the last decades of vacuum tube hi-fi development. An industrial tube variant is known as 6267. In the former Soviet Union a variant was also produced as type 6Zh32P (Russian: 6Ж32П.) As of 2012[update] EF86s were being produced in Russia in two versions under the Electro-Harmonix brand and in the Slovak Republic as JJ Electronic (formerly Tesla).
The EF86 is a high transconductance sharp cutoff pentode vacuum tube with Noval (B9A) base for audio-frequency applications. It was introduced by the Mullard...
Cliff Richard's concerts. The AC15 was powered by a pair of EL84 tubes, an EF86-driven "Normal" channel, an ECC83-driven "Vib-Trem" channel, and rectified...
properly set. This device is the same as the European type EF184. The 6267 / EF86 pentode was a vacuum tube well suited for use in low-level pre-amplifiers...
construction. The dual channel amplifier uses pre-amp valves (most specifically the EF86 pentode) that are associated with smaller Vox amps. The range includes 15...
ranges of signal and bias on the control grid. Examples include: EF37A, EF86/6267, 1N5GT, 6AU6A, 6J7GT. Often, but not always, in the European valve naming...
pedals feature a unique EF86 driven tube design coupled with a variable Bias control to tailor the distortion behavior of the EF86. Power Station Introduced...
Popular low power tubes were dual triodes (ECCnn, 12Ax7 series) plus the EF86 pentode, and power valves were mostly being beam tetrode and pentodes (EL84...
made (with and without due credit). To promote their new 9-pin tubes EZ80, EF86 and EL84, the Anglo-Dutch Mullard Company developed, in 1954, a famous and...
produced by the system. Valve preamplifiers use triodes or low-noise pentodes (EF86). Mains hum from the heater filaments is a potential problem in low-level...
of the United States and most of the European tubes, e.g., 12AX7-ECC83, EF86 and EL84, produced commercially towards the end of the era before transistors...
E80F is commonly sought after as a high quality replacement for the similar EF86 type in guitar amplifiers). The letters "CC" indicated the two triodes and...
February 2010 list (429316) 2010 EU70 13 January 2010 list (429322) 2010 EF86 14 January 2010 list (429354) 2010 GE28 31 January 2010 list (429358) 2010...
noiseless tube having a source of voltage noise in series with the grid. For the EF86 tube, for example, this voltage noise is specified (see e.g., the Valvo,...
valve having a source of voltage noise in series with the grid. For the EF86 low-noise audio pentode valve, for example, this voltage noise is specified...
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