TELEFUNKEN Elektroakustik EL84-TK Power Amp Tubes Replacement EL84 6BQ5 Tube

The TELEFUNKEN EL84-TK is a perfect replacement for any EL84 / 6BQ5 tube offering a reliable and great sound. It is a thermionic valve of the power pentode type.

Originally designed for the output stages of audio frequency amplifiers, the EL84 can deliver up to 17 watts. Although it is physically smaller than most common output tubes, this pentode tube can really deliver. In many ways it is similar to the EL34 but without the output "horse power".

The EL84, like its EL34 cousin, are found in many BrIt'sh amplifiers, particularly those from VOX. When overdriven, the EL84 power tubes in these amplifiers produce a distinctive chiming and articulate sound when compared to 6L6 tubes more commonly used in American amplifiers.

Technical Specs

Type
A.F. Output Pentode
Base
Noval
Number of Pins
9-pin

-Indirect by A.C. or D.C.
Heater Voltage
6.3 V
Heater Current
760 mA

Grid #1 Cathode
10 pF
Plate to all except Grid #1
5.1 pF
Grid #1 to Plate
0.6 pF
Grid #1 to Heater
0.15 pF

Plate Voltage (in cold condition)
300 V
Plate Dissipation
12 W
Grid #2 Voltage
300 V
Grid #2 Dissipation
2 W
Grid #1 Voltage
-100 V
Cathode Current
65 mA
Grid #1 Resistor (automatic bias)
1 M?
Grid #1 Resistor (fixed bias)
0.3 M?
Bathode to Heater Voltage
100 V

PlateVoltage
250 V
Grid #2 Voltage
25 V
Grid #1 Voltage
-7.3 V
Cathode Resistor
5.2 k
Plate Current
48 mA
Grid #2 Current
5.5 mA
Transconductance
11.3 mA/V
Internal Plate Resistance
40 k
Amplification Factor
19
Plate Current at Cutoff (Vg1 = -30V)
<7 mA
Grid #1 Driving Voltage (when PO = 50 mW)
0.3 V
Grid #1 Driving Voltage (when PO = 6 W)
4.2 V
Output Power (at 10% THD with fixed grid bias)
5.7 W
Output Power (when Ig1 = 0.3 µA)
6 W