It’s been said that the Mullard sound can be most likened to a warm British jacket of the finest tweed. I can’t say I know what that means exactly, but I do like the way it sounds. And I like how Mullard tubes sound, too. There's logic hiding in there somewhere. Enticingly intimate and warm, almost sweetly so, it’s always a close, handsy dance when listening to a Mullard. You're right there, and tonight it’s a for-your-ears-only private concert. The top end is silky, airy, never rolling off. The soundstage is big, open and warm like an overdue hug that brings you in for the squeeze and never lets go. The mid range is full, clean, and mesmerizingly human at times.The low end is weighty, not too fast, not precise but not messy or dishonest either. Smooth, rich, musical, they just flow. The best word I know to describe them is mellifluous.
Tube guru Brent Jesse once used a few more words, writing that “These tubes reproduce the human voice, especially female voices, with haunting realism.” Well, anyone that’s heard them sing knows that.
Strangely, mC1’s seem to always be sold as singles. Maybe it’s because they're expensive. Maybe not. An idiosyncrasy of tube culture that needs to be talked about more. It feels almost taboo, like I’m grossly violating some secret, unwritten law of the great tube doctrine by even considering listing mC1 pairs. Well, maybe. But these dog-eared stacks of parking tickets don’t lie, I’m not much for following the rule of law, written or unwritten.
For your consideration:
Tube 1 (B7K)
Test Results (32=Good 48=New): 44/32 & 44/32 = Very Strong
Getter: Field Goal, Plates: 17mm, Long, Series: I27 mC1, Factory: Blackburn Born: 1957, Code (B7K)
Special Power: Red Tip / Medically Selected / Special Quality
Tube 2 (B7K)
Test Results (32=Good 48=New): 42/32 & 46/32 = Very Strong
Getter: Field Goal, Plates: 17mm, Long, Series: I27 mC1, Factory: Blackburn Born: 1957, Code (B7K)
Special Power: N/A
12AX7’s generally come in two sizes, Short/14mm or Long/17mm. And it’s important to understand their differences, because they are different. Most importantly, they sound different. A difference that can be summed up in three words: Lively, 3D, and Open.
Long plates came along first, way back in 1949. The lived primarily through the 50’s until in the late 50’s/early 60’s the short plate was invented as a way to combat what they saw at the time as shortcomings in the long plate, primarily length of life and a proneness to becoming microphonic. The short plates did just that, they lived longer and were more stabler, but are generally believed to not sound as detailed, musical or have as large of a soundstage as their older, longer-haired cousins.
This distinction is most relevant to American made tubes. First generation 12AX7s were all black plates and are highly prized (and thus expensive) for their fantastically sweet sound. A sound created by a tube that emphasizes, by design, even order harmonics over fundamental tone. In general, black plates have a warmer, more complex, more harmonic and fuller sound than their grey-haired counter parts.
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