Description
Here is a matched pair of EL84 tubes made by Telefunken in Germany, the tubes bear the Mazda label.
Detailed description
Telefunken produced their EL84 pentode tubes in the Berlin factory. Telefunken tubes are considered by many hifi-enthusiasts as the creme the la creme. Telefunken EL84 tubes can be recognised easily by their round plates and the diamond mark in the bottom. Telefunken EL84 is considered as one of the best sounding EL84. The tubes were thoroughly tested and have strong test values (note test results below). Very strong tubes that look and test new but probably have been used lightly.
Test method
Mutual transconductance, plate current, gas and shorts tested with: AVO CT-160 (Dutch army tester), Utracer3+, Philips 1532, RFT stabilised power supply and 2x Keithley 2700. Test conditions: Anode 250V, Screen 250V, Grid -7.3V, Filament 6,3V, Rated Ia = 48mA, Gm = 11,3 mA/V. AVO Valve Data Manual 23rd edition 1981 Before testing they were burned in for 48 hours.
Test results*
The measurement data below show that the tubes test NOS and are matched.
| Valve
V44 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
48 mA
11,1 mA/V OK |
NOS
NOS
|
| Valve
V45 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
52 mA
11,3 mA/V OK |
NOS
NOS
|
* Please read the test notes !
Summarized description
| Tube type | EL84 |
| Quantity of Tubes | One pair |
| Brand | Telefunken, labeled Mazda |
| Manufactured in | Berlin, Germany |
| Date code | None |
| Plate Construction | Round grey plate construction |
| Getter Construction | Telefunken style halo getter |
| Print Condition | one good and one bad; see pictures |
| Box included | Mazda boxes; not EL84 boxes |
| Equivalent tubes: | CV2975 6BQ5 7189 E84L |
| General test results | NOS |
Ask any questions before bidding. Thank you.
