This high impedance amplifier triode is designed specifically for audio use and has a high amplification factor of 100.
This valve is found in todays designs of hi-fi audio amplifiers. In the classic Mullard designs of the 1950’s and 1960’s the valve’s two halves were used as second stage amplification and cathode coupled phase splitter. The phase splitter being required so that the push-pull output stage was driven correctly.
The envelope is 21 mm in diameter and the average diameter for B9A valves is 20 mm. Length excluding pins is 48 mm.
The Ei EL84 is a power amplifier pentode designed for use in the audio frequency power output stage of television and radio receivers and in high fidelity amplifiers.
The performance curves for each tube produced are stored in the computer which controls the test sequence. This same computer then performs the matching algorithm, working from the entire single tube inventory, to find the best matched pair for each order.
The Penta Laboratories KT66 is a high slope, indirectly heated beam triode designed principally for use in the output stage of audio amplifiers. It may also be used as an oscillator or R.F. power amplifier for frequencies up to 30Mc/s.
It is suitable for either single or push-pull audio operation, and may be employed as a triode with screen connected through a 100 ohm resistor to the anode.
The KT88 has an absolute maximum anode dissipation rating of 50W and is designed for use in the output stage of an A.F. amplifier. Two tubes in Class AB1 give a continuous output of up to 120W. The KT88 is also suitable for use as a series tube in a stabilized power supply.