The CV4003 type valve is a special quality version of the ECC82 double triode. This double triode was often used in instrumentation applications as well as audio.

An amplification factor of 17 is quoted.

The thin glass tube envelope is 20 mm in diameter and the length excluding the B9A base pins, is 46 mm.

Reference: Datasheet.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	a(2)	g1(2)	k(2)	h	h	a(1)	g1(1)	k(1)	hct

 
Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	gm
	6.3	0.3	250	-8.5	10.5	2.2

Thanks to Frank Philipse for supplying the above PDF datasheet