No other tubes can deliver vocals like the Blackburn Mullard's, and that's a fact. These 12DW7s are extremely hard to find today and are becoming every serious audiophile's darling.12DW7/ECC832 combines 12AX7/ECC83 and 12AU7/ECC82, where the former is used as the 1st stage and the latter as the 2nd stage.
Sound Qualities
The overall tonality of Mullard 12DW7 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!
Appearance & cosmetic condition
These tubes have nearly 100% of the paint and lettering remaining, and the identical Blackburn date codes are perfectly visible:
B1J (B = Blackburn, 1 = 1961, J = October)
Professional Tube Testing
This set was tested and certified by RoeTest V11 tester with the following result:
