EAT KT88 Diamond Valve

Full Description

Overview
A KT88 tube that is in a league of its own. This KT88 tube is available in factory-matched quartets. Its construction features include black plates, black metal base, and gold pins. The EAT KT88 has a designed maximum anode dissipation rating of 35W and is recommended for use in the output stage of an a.f. amplifier. Two valves in class AB1 give a continuous output of up to 100W. The KT88 is also suitable for use as a series valve in stabilized power supply.

Specs
Valve Type: *KT88 DIAMOND*
Size – included socket: 5.2 × 12.5 cm / 2 × 4.9 inch
Characteristics:
Plate dissipation (Max.): 40 W
Grid dissipation (Max.) : 6 W
Cooling: radiation
Heater – Voltage: 6.3 V
Heater – Current: 1.6 A

Maximum ratings:
Anode voltage: 800 V
Screen grid voltage: 600 V
Va, g2: 600 V
– Vgl: 200 V
Pa: 35 W
Pg2: 6 W
Pa + g2: 40 W
Ik: 230 mA
Vh -k: 200 V
Tbulb: 250 °C

Capacitances (measured on a cold unscreened valve)
Triode connection
Cgl -a, g2: 7.9 pF
Cg1 -all less a, g2: 9.8 pF
Ca, g2 -all less g1: 17 pF
Tetrode connection
Cg 1 -a: 1.3 pF
Cg 1 -all less a: 17 pF
Ca -all less g1: 12 pF

Push – Pull, Class AB 1, Cathode Bias, Ultra – Linear Connection (40% Tapping Points).
Vag2 (b): 500 – 375 V
Vag2 (o): 436 – 328 V
Ia + g2 (o): 2 × 87 – 2 × 87 mA
Ia + g2 (max. sig): 2 × 99 – 2 × 96 mA
RL (a-a): 6 – 5 k Ohms
Rk*: 2 × 600 – 2 × 400 Ohms
– Vg1 (approx.): 52 – 35 V
Pout : 50 – 30 W
Dtot: 1,5 – 1 %
I.M.D. : 4 – 3 %
Wa + g2 (o): 2 × 38 – 2 × 28.5 W
Wa + g2 (max. sin): 2 × 17 – 2 × 16 W
V g1 – g1 ac: 104 – 71 V
Zout: 4.8 – 4.5 k Ohms
*It is essential to use two separate cathode bias resistors.
I.M.D. intermodulation distortion measured using two input signals at 50 and 6000 Hz (ratio of amplitudes 4:1)

Push – Pull, Class AB 1, Cathode Bias, Triode connection.
Vag2 (b): 400 – 485 V
Vag2 (o): 349 – 422 V
Ia + g2 (o): 2 × 76 – 2 × 94 mA
Ia + g2 (max. sig): 2 × 80 – 2 × 201 mA
RL (a – a): 4 – 4 k Ohms
-Vg1 (approx.): 40 – 50 V
Pout: 17 – 31 W
Dout: 1.5 – 1.5 %
I.M.D.: 5.6 – 5.6 %
Wa + g2 (o): 2 × 26.5 – 2 × 40 W
Wa + g2 (max. sin): 2 × 29 – 2 × 27 W
V g1 – g1 ac: 78 – 114 V
Rk: 2 × 525 – 2 × 525 Ohms
Zout: 4.8 – 4.5 k Ohms