Description

6CA7 is high property audio output pentode, its anode limited dissipation power is 25W, the output power is over 10W when it is used as class A1 in amplifier single tube, and it is over 35W when it is used as class AB1 double tubes.
6CA7 is very similar with EL34, which can be replaced by each other.

Heater
UH……………………………6.3 V
IH……………………………1.5 A
Static Parameter
Ua…………………………… 250 V
Ug2……………………………250 V
Ug3…………………………… 0 V
-Ug1…………………………12.2 V
Ia…………………………… 100 mA
Gm…………………………… 11 mA/V
ri…………………………… 15 kΩ
μg1-g2………………………11
Maximum Rating
Ua……………………… 800 V
Ug2………………… 500 V
Ug1………………… -100 V
Pa………………… 25 W
Pg2…………… 8 W
Ik………………………150 mA
Rg1
With cathode bias………………………0.7 MΩ
With fixed bias……………………0.5 MΩ
Uh-k ………………±100 V
Tbulb………………………250 ℃
Direct Interelectrode Capacitances
input…………………… 15.2 PF
output…………………… 8.4 PF
grid to plate…………………… 1.1 PF
grid to filament……… 1.0 PF
Cathode to filament…………… 10 PF
Recommended Operating Conditions(reference value)
class A1, singel tube, fixed bias
Ua(b) …………………… 265 265 V
Ua……………………………250 250 V
Ug2……………………… Rg2=2k Rg2=0
Ug3……………………………0 0 V
-Ug1……………………… 14.5 13.5 V
Ia(0) ………………………70 100 mA
Ig2(0) …………………… 10 14.9 mA
Gm…………………………… 9 11 mA/V
ri……………………………18 15 kΩ
RL…………………………… 3 2 kΩ
Pout………………………… 8 11 W
Dtot…………………………10 10 %
push-pull, class B1, fixed bias
Ua……………………………375 400 V
▲Rg2………………………… 600 800 Ω
Ug3………………………… 0 0 V
-Ug1………………………… 33 36 V
Ia(0) …………………2×30 2×30 mA
Ia(maxsig) ………2×107.5 2×110.5 mA
Ig2(0) ………………2×4.7 2×4.5 mA
Ig2(maxsig) ………2×23.5 2×23 mA
Rl(a-a) ………………3.5 3.5 kΩ
ü(g1-g1)(r.M.S) ……… 46.7 50 V
Pout……………………48 54 W
Dtot……………………2.8 1.6 %
▲ Rg2is used in two tubes.
push-pull, classB1, cathode bias, ultra-linear connection
(43% tapping points)
Ua………………………………430 V
Rg2…………………………… 2×1 kΩ
Ia(0) ………………………2×62.5 mA
Ia(max.sig) ……………… 2×65 mA
Ig2(0) ………………………2×10 mA
Ig2(max.sig) …………… 2×10.2 mA
Rk……………………………2×470 Ω
?(g1-g1)(r.M.S) ……………35 V
RL(a-a) ……………………… 6 kΩ
Pout……………………………20 W
Dtot………………………… 0.35 %