|   | 
				 
				Double triode 
				Introduced in 
				1948 
					
						| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |  
						| a2 | g2 | k2 | f | f | a1 | g1 | k1 | hct |  Heaters can also be connected for 6.3V, 350mA operation. 
					
						| Vf | Af | Va | Vg | mAa | ra | gm | Pdiss |  
						| 12.6 | 0.15 | 250 | -2 | 1.2 | 62,500 | 1.6 | 1 |  
					
						| Equivalent | 12AD7, 12AX7, 12DF7, 12DT7, 12DM7, 
						5751, 7025, 7058, 7729, 
						B339, 
						CV4004, CV4110,
						 CV492,
						E83CC, ECC83,
						M8137 |  |