Description
Pair: ECC83 Marconi f92 long plate; made in 1959 by Mullard UK.
Description
This is a pair ECC83 double triodes that are produced for Marconi by Mullard in Blackburn UK. The tubes have a ring getter, copper grid posts and long plates (Version f92; introduced immediately after the mC-series), see pictures. Both tubes are manufactured in october 1959. The tubes are NOS !; no signs of use at all. Very healthy tubes with NOS specs and excellent matching systems; see test results.
The tubes look and measure unused; see pictures!
Sonics
The early Marconi ECC83 B339, like the long plate Mullard, is highly regarded; delivers space and transparency. I refer to the many threads on the web for more information. Excellent preamp valve, low noise, very smooth extended highs, very good in phono stages. Balanced and smooth sounding with liquid midrange, recommended!
Note from the web: “The overall tonality of Mullard ECC83 tubes is warm and lively with a very spacious sound stage. “Like a warm British jacket of the finest tweed, these glorious tubes have an attractive sweet warmth in their midrange and lower regions.” This is how the experts on audiotubes.com describe the sound signature of British-made Mullard tubes. The top end is silky and pleasant and doesn’t get rolled off. They retain a fine sense of “air” at the top, and the upper midrange is smooth and liquid. These tubes reproduce the human voice, especially female voices, with haunting realism. The British made Mullard tubes are also known to have an attractive sparkle at the top with rich bass…now we know where that “warm British jacket” comes from!
Test results*
The measurement data below show that both systems are precisely matched and balanced. And fully in line with the factory specification for a NOS-tube.
| Valve 1
V298 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
1,3/ 1,2 mA
1,7/ 1,7 mA/V OK |
= NOS
= NOS |
| Valve 2
V299 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
1,3/ 1,2 mA
1,7/ 1,6 mA/V OK |
= NOS
= NOS
|
Where NOS is : Ia = 1,1 to 1,4mA, Gm= 1,3 to 1,95 mA/V.
* For test methods and factory specification read the tube testing page.
Short description
| Tube type | ECC83 |
| Quantity of Tubes | One pair |
| Brand | Marconi |
| Manufactured | Mullard Blackburn UK |
| Dates | 1959 / 1959 (codes: f92 B 9J) |
| Construction | Long ribbed plates, copper grid posts |
| Getter Construction | Halo getter |
| Print Condition | Both excellent; see pictures |
| Box included | White box |
| Equivalent tubes: | 12AX7, ECC803S, CV4004, 12AX7A, B339, 12AX7WA |
| General test results | NOS |
