EAT KT88 Vacuum Tube

Out of stock

Out of stock

Sold as a set of 4

A KT88 tube that is in a league of it's own. This KT88 tube is available in factory-matched quartets. It's construction features include black plates, black metal base, and gold pins.

A KT88 tube that is in a league of it's own

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. It's construction features include black plates, black metal base, and gold pins.

Valve Type: *KT88 DIAMOND*
Size including socket: 5.2 × 12.5 cm / 2 × 4.9 inch

Burn-in Procedure

  • Valves need to be burned-in within 50-100 hours under conditions shown in the specs
  • Correct burn-in will assure maximum lifetime and genuine sound
  • During the burn-in use different volume levels from the beginning, and increase the maximum volume gradually
  • Do not use stand-by mode during burn-in and let the tubes cool down after each use
  • Do not overdrive or tap on a working tube, this will cause permanent filament damage
  • Burn in with noise tools, burn in cd, radio noise, pink noise, etc.
  • Allow the valves enough air circulation

Press and Reviews

Hi-Fi News
Hi-Fi News

by Ken Kessler
Jul. 2005

Hi-Fi+ 2004 Product of the Year

2004 Product of the Year
by Roy Gregory

Audio Smorgasbord
Audio Smorgasbord

by Chris Binns

E.A.T. Web Exclusive
E.A.T. Web Exclusive

by Scot Markwell
Sept. 2003

AV Guide Monthly Review
AV Guide Monthly

by Scot Markwell
Apr. 2004

Warranty Certificate Download

EAT will replace the tubes providing the following conditions for all customers:

1. The tubes have a warranty of 12 months or 2000 hours of use starting with the date of purchase. The purchase data must be written and stamped by the distributor/dealer within 21 days after purchase (registration).

2. In the event of failure of the tubes, EAT or distributors/dealers will do replacement within valid warranty claims. The tubes must be returned with the original box and warranty certificate (date of purchase stamp-registration & complete return form) and prepaid shipment, otherwise warranty will be void.

3. Warranty is voided due to improper handling:

  • Make sure that the electrical specifications of your amplifier are correct before using tubes in your circuit.
  • Failure to follow this manufacturer’s recommendation may result in damage to your amplifier or valves and automatically voids this warranty.
  • The tubes should run at the standard specs (see technical data sheet ) and not steadily at the maximum values.
  • EuroAudioteam will not be liable for damage resulting from improper use of tubes in your amplifier. Abuse, accidental damage or incorrect use of the tube will be determined by EAT.
  • Only expert technicians can change the working points of the tube. Improper use of the tube or incorrect application of the tube to a circuit cannot be covered by our warranty.

Shipment procedure:

  • Use original box: Insufficient package for shipment is a cause of broken pieces inside of valve
  • Prevent tube from side shock
  • Shipment costs are covered by buyer
  • Returned tubes must include warranty certificate ( registration), return form and original package



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


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


6 month warranty
6 month Warranty

*I.M.D. intermodulation distortion measured using two input signals at 50 and 6000 Hz (ration of amplitudes 4:1).


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