Description
Here is a pair of Philips GZ34 tubes; very early 1959 production (same production month!), produced in the Philips factory in Sittard, Netherlands. This is the famous and ultra rare Double-D GZ34 version. According to many even better than the already outstanding Mullard/Philips rectifiers. The tubes have a DD-getter and an f33 etch code. The GZ34 is a full wave rectifier. 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. The tubes are supplied in Philips boxes.
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. Tube number 19 even is assumed to be new and unused.
GZ34
V19 |
Ia (anode current):
Gas test, Shorts test:
|
129 / 129 mA
OK
|
< NOS
|
GZ34 2
V23 |
Ia (anode current):
Gas test, Shorts test:
|
131 / 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
Tube type | GZ34 |
Quantity of Tubes | One pair |
Brand | Philips Miniwatt |
Manufactured in | Sttard, Netherlands |
Date codes | f33 X 9L & f33 X 9L (1959) |
Construction | Grey plates with 0 dents, brown base |
Getter Construction | DD-getter |
Print Condition | See pictures |
Box included | Original Philips box |
Equivalent tubes: | 5AR4 |
General test results | < NOS |