EAT KT88 Diamond Vacuum Tube- Matched Quad Box Set

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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.

  • 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)

We are in the business of creating satisfied customers. We hope you love your purchase, but in the event that you are not satisfied, you may return unopened and unused items within 30 days for a full refund of the purchase price.

In the event that merchandise is not in its original condition, has been opened, or is missing packaging, manuals, accessories or other components a partial refund will be given.  Partial refunds are calculated on a case-by-case basis but incur a minimum 15% restocking fee.

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Attn: Returns
RA# (Insert RA #)
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Lake Grove, NY 11755

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