GZ34 pair; Philips Miniwatt, Mullard production, NOS specs v10/v21

Description

Here is a pair of Mullard GZ34 tubes; old production, produced in the Blackburn factory in the UK. The Mullard GZ34 is a full wave rectifier. These tubes bear the brand name Philips Miniwatt. The tubes have a halo-getters and an f32 etch code. The Mullard GZ34 is famous for its contribution to the tonal quality of tube amplifiers and their extreme long life. They are highly regarded also for application in guitar amplifiers. 

These Mullard made tubes deliver superior performance compared to the Chinese and Russian new production.   

Test method

Anode current, gas and shorts tested with: AVO CT-160 (Dutch army tester), Utracer3+, AVO Valve Data Manual 23rd edition 1981, Philips 1532, RFT stabilised power supply and 2x Keithley 2700. Test condition: Ua (plate voltage) = 10,5 Volts.

Test results*

The measurement data below show that the GZ34 tubes are in excellent condition and fulfil the factory requirements for a new tube.

Both tubes are balanced extremely; within en between! 

GZ34 V10	Ia (anode current): Gas test, Shorts test:	139 / 131 mA       OK	<  NOS
GZ34 2 V21	Ia (anode current): Gas test, Shorts test:	136 / 135 mA       OK	<  NOS

*The emission value for a new GZ34 valve at the used test conditions is: 120 Milliamperes (mA).  (Factory data sheet)

 

* Specified measurement data

Test results on other testing devices may supply different values. Just in case of mismatch of “standard” values of the different tube testers “standards”. My test results refer to tube data sheets provided by the original tube producers. (You’ll find them easily on the web.) And are obtained with the specified test equipment.

Please read our test notes and shipping policy before buying !

Short description