Description
Pair Valvo ECC81 made by Siemens & Halske in 1967
This is a pair ECC81 produced by Siemens & Halske in Munich. The tubes are pulls from unused military stock; that’s why they were dusty. The date codes VF1 # 7J are clearly visible and indicate October 1967 as production date. Very healthy tubes with good specs; see test results.
This ECC81 has a small halo getter and a 1-hole plate.
Sonics
The tube type is highly regarded; I refer to the few threads on the web for more information. Excellent valve for the preamp section; low noise, very smooth extended highs. Balanced and smooth sounding, recommended!
Test results
Both tubes test NOS. The internal balance between the triode sections is better than 3%. The tubes are matched all differences are smaller than 5%.
For test methods and factory specification read the tube testing page.
| Valve 1
V32 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
9,0/ 9,2 mA
5,3/ 5,4 mA/V OK |
= NOS
= NOS |
| Valve 2
V33 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
9,0/ 8,8 mA
5,3/ 5,1 mA/V OK |
= NOS
= NOS
|
Short description
| Tube type | ECC81 |
| Quantity of Tubes | One pair |
| Brand | Valvo |
| Manufactured in | Siemens & Halske, Munich, Germany |
| Dates | 1967 / 1967 |
| Construction | 1-hole ribbed plate |
| Getter Construction | small halo getter |
| Print Condition | pristine; see pictures |
| Box included | Old Valvo box (not for a ECC81!) |
| Equivalent tubes: | ECC81, ECC801S, 12AT7 |
| General test results | NOS specs |
