Tube EF 83 or Röhre EF83 ID1190, Vacuum Pentode, Noval, 9 pin miniature (USA pico-9) B9A and Audio Frequency shown. Radio tubes are valves.

The EF83 is a variable-mu AF voltage amplifying pentode. The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 48 mm tall. References: Data-sheet, 3002 & 1040. Type EF83 was first introduced in 1956. See also 1956 adverts. Thanks to Frank Philipse for supplying the above PDF datasheet. Updated July 04, 2018.

The E83F Mullard pentode is a special quality version of the EF83. The valve was designed for class A audio amplification in telephone equipment where long life was very important. The audio output was 0.87 Watts and the maximum anode dissipation was 2.1 W.

2021年11月10日 · The EF83 is a variable gain (mu) pentode, usually use in constant level applications. I'm not sure, that using as VAS stage it's the best choice. The 180F is super VAS tube ... if you want single stage VAS and -relatively- large gain (about 45-50 as triode).

2007年11月3日 · I recently heard a EF-86 in a 2 X EL-84 amp and I really liked it. I have heard there are a lot of hassles using pentodes in combo amps. Have any of you guys experimented with various pentodes and what are the results you have had?

2005年5月11日 · Note that the control voltage off the diode toward the EF83 grid is also dribbled into the preceding EF86 grid (through 15M+15M/10M). Two stages are under AVC. That explains why they could get away with just 16dB of gain reduction in the EF83: while the EF86 is not rated as a vari-gain tube, its gain will drop as the grid is pulled down.

2015年2月19日 · As Dave says, the EF83 is a the variable-mu (or remote cut-off) version of the EF86 and is used to enable compression or constant output level function in audio circuits. A useable feature in tape recorders so as the tape is not driven into saturation.

2008年5月1日 · 积分 37440 金币 25 铜板 37389 交易积分 0 技术积分 26 rmb 0 注册时间 2008-5-1

2022年7月14日 · I rigged up a grid leak biased CC ECC83 stage, and tried to test whether the gain was affected by signal level, ie compression, using a 400Hz sine wave, 20mV to 1.4Vrms (the output clipped above that). Whether the grid leak was 470k or 10M, it didn’t.

2011年6月23日 · EF83 (6BK8) is pin compatible to EF86, however, it is a vari-mu tube. NOTE: shady fleabay sellers are trying to pawn these off as an EF86 replacement. they are NOT an EF86, as the EF 86 is a sharp cut-off pentode. E804S - electrically similar to EF86 with different noval pinning with slightly less filament draw. it is a hi-reliability long-life ...