The EL84 was developed to eliminate the need for a driver tube in radios, so it has rather more gain than is usual in a power pentode.

Many guitar-amplifiers routinely run EL84 tubes in excess of 400VDC, with the Traynor Guitarmate reportedly putting out 25W RMS with 2 EL84s in a push–pull configuration and a B+ between 400–420 VDC.

Other manufacturers followed with their versions, such as the N709 from General Electric Co. Ltd. of England and the 6P15 from UK brand Mazda, that were designed to be drop-in substitutes.

While not necessarily a true military version of the tube (in fact it is more comparable to the 7189), 6P14P-EVs are known for their low noise and durability.

Specifications given for the EL84, PL84, and UL84 are from Philips; RCA and Sylvania list slightly higher voltage ratings for Va and Vkf and lower for Vg2 for the xCW5 series – the 6CW5/EL86, 8CW5/XL86, 10CW5/LL86, 15CW5/PL84, and 30CW5/HL84.