The output stage is preceded by a voltage amplification stage ( pentode or twin triode ) and a phase-splitter ( twin triode ).
32.
The AC30 / 4 also carried over the AC15's preamplifier circuit, which included the EF86 pentode in its " Normal " channel.
33.
The screen found in tetrodes and pentodes, greatly increases the valve's gain by reducing the effect of anode voltage on anode current.
34.
Other schisms concern the use of triodes vs . tetrodes and pentodes, and the use of directly heated tubes vs . indirectly heated tubes.
35.
The lower-power noval base EL84 power pentode was widely used in less expensive 10-watt ultralinear power amplifiers, still of high fidelity.
36.
The EF86 is much less noisy than other pentodes, but slightly noisier than some triodes at about 2 �V equivalent input noise to 10 kHz.
37.
This variation usually appears in the pentode form of the valve, where it is then called a variable-mu pentode or remote-cutoff pentode.
38.
This variation usually appears in the pentode form of the valve, where it is then called a variable-mu pentode or remote-cutoff pentode.
39.
This variation usually appears in the pentode form of the valve, where it is then called a variable-mu pentode or remote-cutoff pentode.
40.
The ubiquitous Mullard EL34 ( 6CA7 ), although manufactured by Mullard as a pentode, was also produced by other manufacturers as a beam tetrode instead.