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KT33C

Sensibly equivalent to:
CV1503 VR503
    
Extras ▼

 

The KT33C audio power output valve was introduced by M-OV in 1939 and replaced the KT33. This version had a heater centre tap and was designed for series heater chains. This exhibit is branded GEC for use in professional equipment.
For the 5 Watts output the anode load would be 3,000 Ohms. The distortion at full power is 7.5%.
The GEC brand label.
The lower mica and pinch. The rectangular cathode has four insulated heater wires threaded through it.
The classic envelope is 44 mm in diameter and, excluding the IO base pins, is 109 mm tall.
References: Data-sheet & 1043. Type KT33C was first introduced in 1939.

 

Pin Connections
IO
1
2
3
4
5
6
7
8
hct
h
a
g2
g1
-
h
k

 

Absolute Maximum Operating Conditions
Beam Tetrode
Vh
Ah
Va
Vs
Vg
mAa
mAs
gm
Pout
26
0.3
200
200
-13.2
60
10
10.0
5
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated August 24, 2021.
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