TELEFUNKEN Elektroakustik Matched Pair of EL84-TK Black Diamond Series 9 Pin Replacement Vacuum 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 British 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 Specifications

Type
R.F. Output Pentode
Base
Noval
Number of Pins
9-Pin

Grid #1 to Cathode
Cg1k 10 pF
Plate to All Except Grid #1
Ca 5.1 pF
Grid #1 to Plate
Cg1a 0.6 pF
Grid #1 to Heater
Cg1f 0.15 pF

Plate Voltage
Va 300 V
Plate Dissipation
Pa 12 W
Grid $2 Voltage
Vg2 300 V
Grid #2 Dissipation
Pg2 2 W
Grid #1 Voltage
Vg1 -100 V
Cathode Current
Ik 65 mA
Grid #1 Resistor (Automatic Bias)
Rg1 1 M ohm
Grid #1 Resistor (Fixed Bias)
Rg1 0.3. M ohm

Plate Voltage
Va 250 V
Grid #2 Voltage
Vg2 250 V
Grid #1 Voltage
Vg1 -7.3 V
Cathode Resistor
RK-135 ohm
Plate Resistor
Ra 5.2 k ohm
Plate Current
Ia 48 mA
Grid #2 Current
Ig2 5.5 mA
Transconductance
gm 11.3 mA/V
Amplification Factor
µg1g2 19
Inter Plate Resistance (Approx
Ra 40 k ohm
Grid #1 Driving Voltage (When Po= 50 mW)
Vg1(Po = 50mW) 0.3 V
Grid #1 Driving Voltage (When PO = 6 W)
Vg1 (Po = 6W) 4.2 V
Output Power (at 10% THD with fixed grid bias)
Po (10% THD) 5.7 W
Output Power (When Ig1=0.3µA)
Po 6 W