Where do other 12ax7's test at on the Maximatcher preamp versus the EH7025's?
Different 12AX7 have different measurements depending on the brand. They're all slightly individualistic though even though they're made on an assembly line. If you've seen a bell curve that's basically tubes in a nut shell once you start looking at the measurements. It's not so much about brand X vs brand Y but picking the best tube possible for your needs. Almost every tube posted is brand new in a box and measured before seeing an amplifier. Shuguang 5 and 7 are not new for example and you can see that because the transconductance is so different from the others. Shuguang 12AX7 Silver Plates without clip Shuguang factory between 1997-2005 same but I left the NIB in there so you can see what tolerances are really like.
Sometimes you see Psvane or TJ Fullmusic silver pins and they're mostly garbage, factory seconds or factory rejects. Psvane 3 and 4 are gold pins. TJ 3 and 4 came as Northern Electric from Tube Store and 7 from Ruby Tubes. If you ever see a Psvane or a TJ Fullmusic with silver pins odds are you should just run away.
7025 China Welded Plates/Genalex silver pin
1 110, 92 1850, 1970 81, 81
2 111, 104 1740, 1810 83, 82
3 108, 107 1740, 1780 83, 83
4 109, 109 1690, 1720 83, 83
Black Coating 12AX7T
1 81, 89 1880, 2080 81, 81
2 88, 93 1990, 1950 81, 81
3 83, 91 2080, 2110 83, 83
4 96, 94 2080, 2130 84, 82
5 89, 93 2190, 2050 82, 82
6 95, 92 2020, 2090 82, 81
Beijing Triple Mica 6N4-J 12AX7 C8
1 97, 96 1930, 1960 86, 85
2 93, 95 1920, 1810 84, 84
3 94, 90 1850, 1940 84, 84
4 95, 88 1980, 2000 83, 83
5 97, 92 1860, 1900 83, 83
6 96, 92 1960, 2020 84, 84
7 94, 96 1980, 1840 84, 84
Psvane
1 95, 68 1660, 1710 85, 79
2 82, 86 2120, 2000 82, 82
3 88, 87 2200, 2080 82, 82
4 84, 88 2010, 2140 83, 82
5 91, 88 2070, 1570 78, 83
6 93, 92 1950, 1990 78, 75
Shuguang 12AX7B
1 94, 94 2020, 2030 82, 82
2 95, 93 2040, 2030 83, 82
3 87, 88 2100, 1980 84, 82
4 97, 94 1920, 1910 84, 83
5 93, 94 1810, 1770 84, 83
6 94, 93 2030, 1980 83, 83
7 91, 89 1730, 1660 81, 82
Shuguang Bugera
A 97, 91 1880, 1810 84, 82
B 100, 99 1940, 1850 83, 81
C 80, 92 1850, 1980 83, 82
Shuguang Silver Plates with clip 7025A Shuguang 12AX7 1995-2005 12AX7 Silver Special (for V1/Input stage the HIGHGRADE selection RT080 is recommended)
1 89, 89 2070, 2070 85, 82
2 92, 93 1970, 2070 84, 82
3 91, 93 1990, 1820 83, 82
4 92, 92 2010, 1900 83, 82
5 96, 92 1890, 1910 84, 82
6 92, 94 1850, 1970 85, 83
7 96, 93 1790, 1800 85, 84
Shuguang 12AX7 Silver Plates without clip Shuguang factory between 1997-2005
1 109, 106 1760, 1700 80, 81
2 99, 99 1530, 1730 84, 73
3 104, 91 1660, 1620 82, 80
4 101, 103 1650, 1560 83, 83
5 103, 103 1400, 1350 84, 83
6 98, 100 1430, 1500 84, 83
7 103, 103 1570, 1520 84, 84
8 89, 90 1670, 1600 85, 84 (NIB Ruby 12AX7WBC)
9 90, 93 1540, 1540 85, 85 (NIB)
10 94, 94 1580, 1590 86, 85 (NIB)
11 95, 95 1590, 1600 85, 85 (NIB)
Sovtek WB copy
1 101, 96 1630, 1580 82, 82
2 97, 91 1530, 1590 83, 83
3 104, 100 1480, 1560 85, 83
4 94, 96 1560, 1530 83, 83
5 97, 98 1440, 1560 86, 85
6 102, 101 1340, 1420 86, 85
7 99, 96 1610, 1480 85, 85
TJ Full Music Box Plate
1 80, 78 1700, 1740 85, 87
2 85, 81 1640, 1600 86, 80
3 88, 90 1800, 1920 82, 81
4 90, 91 1790, 1790 82, 79
5 86, 84 1610, 1790 81, 74
6 76, 72 1900, 1660 78, 75
7 82, 83 2000, 1910 79, 83
TJ Full Music Mesh Plate
1 85, 84 1830, 1770 85, 86
2 83, 81 1830, 1810 82, 86
JJ
ECC83S
1 98, 100 1860, 1900 86, 84
2 101, 102 1990, 1940 87, 85
3 105, 99 1980, 1860 84, 83
4 103, 96 1970, 1890 82, 82
5 103, 101 1910, 1850 85, 84
6 104, 107 1920, 2020 84, 84
7 97, 96 1900, 1810 83, 83
8 106, 109 2090, 1880 84, 82
ECC803
1 96, 94 1730, 1780 84, 85
2 96, 100 1890, 1800 80, 83
3 97, 97 1740, 1840 84, 84
4 97, 96 1840, 1770 83, 83
E83CC
1 96, 94 1960, 1960 84, 84
2 94, 99 1950, 1880 83, 82
3 97, 98 1820, 1730 85, 85
4 100, 100 1820, 1770 86, 85
5 92, 102 1860, 1970 83, 82
Electro Harmonix
1 90, 89 1820, 1750 83, 84
2 105, 94 1720, 1680 86, 86
3 91, 91 1730, 1780 84, 84
4 99, 99 1850, 1850 81, 83
5 93, 91 1870, 1780 83, 83
6 97, 96 1890, 1840 83, 84
Electro Harmonix 7025
1 83, 85 1600, 1580 86, 85
2 85, 84 1540, 1540 86, 85
3 85, 83 1570, 1530 86, 85
4 85, 83 1580, 1600 86, 85
5 82, 81 1600, 1580 85, 85
Gold Lion
1 97, 97 2190, 2190 82, 82
2 100, 100 2170, 2180 83, 82
3 95, 95 2300, 2280 83, 81
4 97, 96 2300, 2300 83, 82
Gold Lion CV 4004
1 96, 96 2040, 2050 82, 84
2 94, 94 2000, 1980 81, 82
3 93, 93 1810, 1820 80, 82
4 94, 93 1950, 1920 81, 80
Mullard
1 98, 96 2230, 2310 83, 81
2 98, 97 2020, 1960 82, 82
3 100, 97 2040, 2300 83, 81
4 98, 98 2390, 2030 82, 82
5 98, 98 2260, 2220 83, 82
-
Mullard CV4004
1 94, 92 1870, 1720 84, 84
2 93, 95 1780, 1670 86, 84
3 95, 93 1650, 1850 86, 83
4 94, 94 1780, 1930 86, 84
Sovtek 7025
1 98, 95 1680, 1600 84, 70
2 94, 93 1710, 1630 81, 83
3 98, 99 1850, 1820 82, 84
4 89, 89 1660, 1610 82, 79
SovtekWA
1 96, 95 1650, 1670 84, 83
2 91, 93 1700, 1700 84, 84
SovtekWB
1 110, 108 1860, 1810 84, 83
2 110, 106 1820, 1810 82, 83
SovtekWC
1 100, 101 1880, 1890 83, 82
2 102, 101 1900, 1870 83, 84
Sovtek Silver Plate 12AX7WB
1 94, 94 1830, 1750 83, 82
2 93, 95 1780, 1720 82, 82
3 97, 97 1710, 1650 81, 81
4 97, 101 1680, 1760 78, 74?
5 95, 95 1600, 1530 83, 82
6 86, 87 1810, 1810 80, 81
7 93, 90 1790, 1730 83, 82
8 90, 88 1750, 1690 84, 84
Sovtek LPS
1 96, 98 2240, 2170 79, 79
2 100, 99 1940, 2200 84, 82
3 95, 90 2140, 2070 83, 82
4 102, 98 1870, 1970 84, 83
5 96, 95 2240, 2220 85, 84
6 99, 97 2140, 2150 81, 82
Svetlana
1 90, 92 1860, 1880 85, 83
2 94, 94 1900, 1890 83, 83
3 92, 93 1820, 1830 85, 84
4 95, 96 1860, 1910 84, 83
Tung Sol
1 90, 93 2050, 2050 84, 82
2 89, 88 2020, 2050 84, 82
3 95, 94 1790, 1770 84, 85
4 87, 89 1870, 1990
5 88, 89 1970, 1960 83, 82
6 92, 91 1670, 1780 84,83
7 96, 95 1839, 1840 82, 83