The QP25 is a quiescent push-pull double pentode for battery operation. It was listed as current production in 1951.

QPP valves operated in class B and for a 19 Volt peak to peak input signal the QP25 would deliver 1.1 Watt output at 5% distortion. See also QP230.

The box matched the style of the PA20 but was smaller measuring 40 mm square by 115 tall.

The type designation was on the top of the envelope.

The classic envelope is 30 mm in diameter, and excluding the MO base pins, is 70 mm tall.

References: Datasheet & ¹⁰⁴³. Type QP25 was first introduced^¶ in 1939.

 
Pin Connections

MO	1	2	3	4	5	6	7	8
	f-	-	a(2)	g2	g1(2)	g1(1)	a(1)	f+

 
Absolute Maximum Operating Conditions^¶

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	Pout
	2.0	0.2	120	120	-9.75	2.3	0.43	1.2W

Thanks to Frank Philipse for supplying the above PDF datasheet