A KT88 tube that is in a league of its own. This KT88 tube is available in factory-matched quartets. It's construction features include black plates, black metal base, and gold pins.
The E.A.T. 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 a stabilized power supply. The EAT KT88 is one of the best KT88 tubes in production. For a KT88 review.
- 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
I.M.D. intermodulation distortion measured using two input signals at 50 and 6000 Hz (ration of amplitudes 4:1).
Sold as a Matched Quad Box Set (4x KT88 Tubes)