Comparison of several 12AU7

Comparison of several 12AU7

Audition results:
1. Sylvania 5814A (12AU7):
Various musical instruments are listed in the horn and perform their duties; the resolution of the vocal and musical instrument details is more improved than that of 12AT7, the texture of the sound appears powerful at low frequencies but feels a bit turbid, and the mid-frequency vocals already have a moving tone, high The frequency is not lost, but personally hope that if the sense of elegance can be more, it will be more perfect!
2. Tung-Sol 5814A (12AU7):
The timbre performance is significantly better than the Sylvania tube vocal IF, which is truly moving, the tone is crisp and crisp, and the impact of the full frequency band is enhanced; the audio and video imaging ability is excellent, and the high-frequency instruments add a sense of zero movement and elegance --- " "Natural" !! There is nothing wrong, as long as the performance of various musical instruments can feel more natural, of course it is the expression tone | Improved !!
3. GE 5814A (three-tier mica military regulation in the 1950s):
The mid-frequency domain of the human voice presents a special sense of reality. Although the high-pitched range does not have an endless sense of extension, it shows another "mature and stable" sense of hearing, without any particularly sharp notes stimulating the ears. It is said that this type of 5814A (12AU7) tube with built-in 3-layer mica film is specially made in response to military standards. It is believed that the sound performance also produces different timbre trends because of its different internal structure. Personally think that the bass performance of this tube is the most powerful and enjoyable of the 5 12AU7s in this audition !! If the overall timbre of the audio system of the same friends is too high and too bright, it may be complementary with this tube.
4. Sylvania 5814A (regulated by the 3-layer mica army in the 1950s):
The sound direction is basically the same as the first Sylvania 5814A, but the bass range is more compact, and the high range and sound field analysis are more "modern"; the mid-frequency part of the human voice will not be too prominent. Although the high-frequency domain is better than the Sylvania 5814A ordinary tube, when compared with the Tung-Sol 5814A ordinary tube, it lacks an indescribable noble texture, and the timbre performance is slightly biased towards the resolution of the transistor, but don't get it wrong-the sound can be It will definitely not be harsh! Personally feel that this tube is used to play pop music such as POP & ROCK, which is very delicious !!
5. Tung-Sol 12AU7 (50s graphite tube):
The sound field expands suddenly, the resolution sharply rises, the high frequency range is rich in overtones, the texture is noble, and the sweet ~~~ vocal IF is real, the details are natural, and there will be no pressure that is too close to the listener. The proper position and details of the various instruments are expressed. The bass range is strong and the extension is good. Not only has the performance of "sound" and even the level of "music", it is a rare old tube !! This tube The inner wall of the glass is treated with graphite, and the appearance looks like the inside of the entire vacuum tube. The uninformed friends may mistakenly think that it is a tube that has been burnt out by the operation of the head !! In fact, it was so special and rare. In the future, if you have the opportunity to meet, please don't doubt it.
After personal comparison, the ranking suggestions are as follows:
1. Tung-Sol 12AU7 (50s graphite tube) --- please work hard with your friends and collect one to enjoy its charming sound quality.
2. Tung-Sol 5814A (12AU7) ---- The sound is crisp and crisp, sound-resistant and practical, and the C / P quality is extremely high. It is an ideal substitute when you can't find graphite tubes in the 1950s.
3. Sylvania 5814A (three-layered mica in the 1950s) ---- strong analytical power, with a modern tone, who said that the sound of the vacuum tube will be "old and old" ?!
4. GE 5814A (three-layer mica in the 1950s)-the bass is powerful enough!
5. Sylvania 5814A (12AU7) ---- The resolution is ordinary, and the sense of nature is a little lacking.

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