KT88 CV5220 6550 OUTPUT BEAM TETRODE VARIOUS MANUFACTURERS

Kinkless beam tetrode output valve
Manufacturers: GEC Valves , Osram , Marconi , Tung-Sol

The KT88 was first produced by Marconi – Osram Valve, a subsidiary of GEC in 1956 and continued for a 28-year production span. A classic audio output beam tetrode characterized by high power output allayed to low distortion made it ideal for audio amplification, however, it does find use with many guitar amplifiers where an end user prefers a tone showing less distortion to that obtained with the 6550 - which was designed as a servo amplifier valve.

The KT88 is one of the largest valves in its class and can handle significantly higher anode voltages than many of its contemporaries - up to 800 volts. A KT88 push-pull pair in class AB1 fixed bias is capable of 100 watts of output with 2.5% total harmonic distortion or up to about 50W at low distortion in hi-fi applications. The screen grid is sometimes tied to the anode so that it becomes effectively a triode with a lower maximum power output, but considered by some users to have superior sonic quality.

The transmitting tubes TT21 and TT22 have almost identical transfer characteristics to KT88 but a different pinout, and by virtue of their anode being connected to the top cap have a higher plate voltage rating (1.25 kilovolt) and a higher power output capability of 200 watts in class AB1 push pull.

Exotica that utilized the KT88 include the: -

Blackstar Series One-200

Fryette Two/Ninety-two

Hiwatt Custom 200 & 400 Bass Head

Jadis JA30

Jolida 502B

Kerry King Signature JC800

Lux A3700

Marshall 2203KK

Marshall JCM800

McIntosh MC-275

McIntosh MC-2102

McIntosh M-175

Orange Thunderverb

Pitbull Ultralead

Reeves Custom 225 bass

Sig:X

Sound City L/B200

Splawn Nitro, Pro, Competition, Superstock

THD Bi Valve Guitar

Woo Audio

 

Picture of TUNG SOL 6550 GRAY PLATE 3-HOLE MATCHED PAIR  FROM 1965/1967
TUNG SOL 6550 GRAY PLATE 3-HOLE MATCHED PAIR FROM 1965/1967
Well what a nice pair of 'coke bottle' shaped three hole, grey electrode cage 1960's Tung-Sol 6550. One has green print and carries the numbering JAN-5550 6714 and the other, red print which carries the number JAN-6550 6528. As can be seen from the test data, both thest at near nominal emission and the test results denote a closely matched pair.
Stock Code: Y62 & Y63
Availability: 1 in stock
€142.60
€91.26
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