EL34 Philips Miniwatt metal base quad. v326/114/144/325

Description

A matched Quad of metal base EL34 tubes made in the Philips Miniwatt factory in Heerlen, Netherlands.

 

Detailed description

The Philips Miniwatt, Holland made metal base EL34 is one of the most desirable EL34 ever produced. All 4 tubes have date code: EY) 56I, which puts their production date in September 1956. The metal base version is considered as the King of all EL34 versions. Introduced in 1953, the metal base EL34 was the first version made and some say the best sounding of the EL34 / 6CA7 family of tubes. 

The metal base Philips Miniwatt EL34 is considered by many as the best sounding of all EL34 tubes ever. 

These tubes deliver superior sonics. I refer to the many reviews on the web.

The quad has good test values and good looks. 

Test results

The measurement data below show that the tubes are matched and in NOS condition. 

Valve  V326

Ia (plate current): Transconductance (Gm): Gas test, Shorts test:

88  mA 10,8  mA/V OK

>  Strong > NOS

Valve  V114

Ia (plate current): Transconductance (Gm): Gas test, Shorts test:

92  mA 10,6  mA/V OK

> Strong > NOS

Valve  V144

Ia (plate current): Transconductance (Gm): Gas test, Shorts test:

94  mA 11,4  mA/V OK

> NOS > NOS

Valve  V325

Ia (plate current): Transconductance (Gm): Gas test, Shorts test:

96  mA 11,9  mA/V OK

> NOS > NOS

Telefunken measuring values for new unused tubes:

• The rated emission value for a new EL34 is:  100 mA. 
• The rated transconductance value for a new EL34 is:  11 mA/V . 
• Rate value ± 10% is judged as NOS

For Telefunken specs info see last picture 

Test condition & equipment:

Mutual transconductance, plate current, gas and shorts test equipment: Utracer3+,AVO Mk IV (Dutch army tester) , AVO Valve Data Manual 23rd edition 1981, RFT stabilised mains,  Philips PE 4832, 2x Korad KA3005P programmable power supply, 2x Keithley 2700 and 2x Fluke 145.

 Test conditions: Ua (plate voltage) = 250 Volts, Us (screen voltage) = 265 Volts, Ug = -13,5 Volts and Uf = 6,3 V ± 3% (factory conditions). Please read our test page.

Summarized description