343:
12AX7 provides a typical voltage gain of about 30; the amplification factor is basically twice the maximum stage gain, as the plate impedance must be matched. Thus half the voltage is across the tube at rest, half across the load resistor. The cathode resistor can be bypassed to reduce or eliminate AC negative feedback and thereby increase gain; maximum gain is about 60 times with a 100k plate load, and a center biased and bypassed cathode, and higher with a larger plate load.
1196:
1220:
1232:
324:
1208:
271:
40:
714:
The 12AX7 is the most common member of what eventually became a large family of twin-triode vacuum tubes, manufactured all over the world, all sharing the same pinout (EIA 9A). Most use heaters which can be optionally wired in series (12.6V, 150 mA) or parallel (6.3V, 300 mA). Other tubes,
1120:
In
European usage special-quality valves of some sort were often indicated by exchanging letters and digits in the name: the E83CC was a special-quality ECC83. In the US a "W" in the designation, as in 12AX7WA, designates the tube as complying with military grade, higher reliability specifications.
342:
Typically a 12AX7 triode is configured with a high-value plate resistor, 100 kohms in most guitar amps and 220 kΩ or more in high-fidelity equipment. Grid bias is most often provided by a cathode resistor. If the cathode resistor is unbypassed, negative feedback is introduced and each half of a
1183:, Tubes sold under Psvane and TAD brand names. Company owns its independent manufacturing facility in Southern China (former Guiguang tube factory) and recently they acquired former small signal tube manufacturing line from Tianjin Quanzheng factory (TJ Full Music)
243:
family of dual-triode amplifier tubes for audio applications. As a popular choice for guitar tube amplifiers, its ongoing use in such equipment makes it one of the few small-signal vacuum tubes in continuous production since it was introduced.
1124:
The 'E' in the
European designation classifies this as having a 6.3 volt heater, whereas the American designation of 12AX7 classifies it as having a 12.6 volt heater. It can, of course, be wired for operation off either voltage.
1116:
versions 12AX7A, 12AD7, 6681, 7025, and 7729; European versions B339, B759, CV492, CV4004, CV8156, CV8222, ECC803, ECC803S, E2164, and M8137; and the lower-gain low-noise versions 5751 and 6851, intended for avionics equipment.
469:
252:
The 12AX7 is a twin triode basically composed of two of the triodes from a 6AV6, a double diode triode. The 6AV6 is a miniature repackaging (with just a single cathode) of the triode and twin diodes from the octal
727:, 12AY7, and the low-voltage 12U7, plus many four-digit EIA series dual triodes. They span a wide range of voltage gain and transconductance. Different versions of each were designed for enhanced ruggedness, low
335:
best suited for low-level audio voltage amplification. In this role it is widely used for the preamplifier (input and mid-level) stages of audio amplifiers. It has relatively high
706:
The initial â12â in the designator implies a 12-volt heater requirement; however, the tube has a center-tapped heater so it can be used in either 6.3-V or 12.6-V heater circuits.
668:
701:
605:
1102:
1072:
1045:
1015:
985:
955:
925:
895:
862:
832:
799:
759:
632:
572:
545:
498:
518:
1481:
348:
1207:
1109:
1514:
310:
1231:
1219:
734:
Those other designs offer lower voltage gain (traded off for higher plate current) than the 12AX7 (which has a voltage gain or
292:
1180:
257:(a double-diode triode used in AM radios), which itself is very similar to the older type 75 triode-diode dating from 1930.
1195:
1490:
715:
which in some cases can be used interchangeably in an emergency or for different performance characteristics, include the
145:
1471:
236:, under developmental number A-4522, it was released for public sale under the 12AX7 identifier on September 15, 1947.
1299:
281:
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1509:
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637:
153:
61:
673:
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1150:
323:
1080:
1050:
1023:
993:
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933:
903:
873:
840:
810:
777:
737:
610:
550:
523:
476:
503:
254:
240:
1133:
As of 2022 versions of the 12AX7/ECC83 are available from the following manufacturers:
206:
1503:
1169:
336:
1519:
1428:
1113:
728:
1486:
1365:"www.thetubestore.com - Tubes with part numbers beginning with 12DW7 - 7247 Tube"
1347:"www.thetubestore.com - Tubes with part numbers beginning with 12AY7 - 6072 Tube"
1466:
1413:
1329:"www.thetubestore.com - Tubes with part numbers beginning with 6C4 - M8080 Tube"
270:
221:
331:
The 12AX7 is a high-gain (typical amplification factor 100), low-plate-current
464:{\displaystyle A_{v}=\mu \times R_{tot}/(r_{P}+R_{tot}+(R_{K}\times (\mu +1))}
1398:
1165:
1154:
1383:
1314:
1158:
295: in this section. Unsourced material may be challenged and removed.
39:
1476:
1146:
1142:
1138:
332:
218:
17:
1176:
804:
771:
724:
720:
716:
322:
144:
1494:
1112:
of ECC83, other
European variations also exist including the low-
1449:
1443:
761:
of 100), and are more suitable for high-frequency applications.
264:
229:
1213:
Various brands of 12AX7, with measuring tape to indicate size
1104:= 20, for use in automotive radios on 12-volt plate supply)
339:
capacitance, making it unsuitable for radio-frequency use.
327:
Anode current characteristic with grid voltage as parameter
1282:
Jung, David (September 2010). "Draw! A 12AX7 'Shootout'".
239:
The 12AX7 was originally intended as replacement for the
870:(September 15, 1947 - dual 6DR4, also like octal 6SL7,
1172:(annual production of approximately two million units)
1083:
1053:
1026:
996:
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106:
96:
88:
83:
75:
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49:
32:
1096:
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1039:
1009:
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919:
889:
856:
826:
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753:
695:
662:
626:
599:
566:
539:
512:
492:
463:
1269:"www.thetubestore.com - 12AX7 / ECC83 Tube Types"
768:12AD7 (October 10, 1955 - 225mA heater - low hum)
1300:"Preamp Gain and Output Impedance Calculator"
8:
764:Some American designs similar to the 12AX7:
670:. If the cathode resistor is bypassed, use
27:Miniature high-gain dual triode vacuum tube
1450:"Changsha Qiangsheng Light Power Co., Ltd"
520:is the amplification factor of the valve,
217:(also known as ECC83) is a miniature dual-
38:
1108:Although commonly known in Europe by its
1088:
1082:
1058:
1052:
1031:
1025:
1001:
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505:
484:
478:
434:
412:
399:
387:
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356:
350:
311:Learn how and when to remove this message
1399:"Changsha Hengyang Electronics Co., Ltd"
1384:"Changsha Hengyang Electronics Co., Ltd"
1260:
1191:
837:12AV7 (February 14, 1950 - dual 6BC4,
29:
1237:Philips JAN 12AX7WA (Joint Army Navy)
930:12AZ7 (March 2, 1951 - 225mA heater,
7:
293:adding citations to reliable sources
547:is the internal plate resistance,
25:
1145:, which produces tubes under the
1230:
1218:
1206:
1194:
1110:MullardâPhilips tube designation
269:
143:
1225:Tungsram ECC83 during operation
607:is the parallel combination of
280:needs additional citations for
634:(external plate resistor) and
458:
455:
443:
427:
392:
1:
807:(October 18, 1946, dual 6C4,
731:, stability, lifespan, etc.
574:is the cathode resistor and
1315:"12AX7 vs 12AT7 Tube Types"
927:= 44, for audio preamp use)
710:Similar twin-triode designs
228:. Developed around 1946 by
1536:
1515:Guitar amplification tubes
900:12AY7 (December 7, 1948 -
774:(May 20, 1947, dual 6AB4,
205:
142:
37:
1472:Several tube datasheets.
1201:Electro-Harmonix 12AX7EH
987:= 100, low microphonics)
897:= 100) dual 12AV6 (6AV6)
663:{\displaystyle R_{load}}
207:Sylvania 12AX7 datasheet
79:0.8 in (20 mm)
71:2.2 in (56 mm)
1477:Reviews of 12ax7 tubes.
696:{\displaystyle R_{K}=0}
600:{\displaystyle R_{tot}}
1098:
1068:
1047:= 100, Second triode:
1041:
1011:
981:
951:
921:
891:
858:
828:
795:
755:
697:
664:
628:
601:
568:
541:
514:
494:
465:
328:
1381:Classic series ECC83,
1099:
1097:{\displaystyle A_{v}}
1069:
1067:{\displaystyle A_{v}}
1042:
1040:{\displaystyle A_{v}}
1020:12DW7 (First triode:
1012:
1010:{\displaystyle A_{v}}
982:
980:{\displaystyle A_{v}}
952:
950:{\displaystyle A_{v}}
922:
920:{\displaystyle A_{v}}
892:
890:{\displaystyle A_{v}}
859:
857:{\displaystyle A_{v}}
829:
827:{\displaystyle A_{v}}
796:
794:{\displaystyle A_{v}}
756:
754:{\displaystyle A_{v}}
698:
665:
629:
627:{\displaystyle R_{P}}
602:
569:
567:{\displaystyle R_{K}}
542:
540:{\displaystyle r_{P}}
515:
495:
493:{\displaystyle A_{v}}
466:
326:
122:Max dissipation Watts
1369:www.thetubestore.com
1351:www.thetubestore.com
1333:www.thetubestore.com
1249:List of vacuum tubes
1181:Hengyang Electronics
1081:
1051:
1024:
994:
964:
934:
904:
874:
841:
811:
778:
738:
674:
638:
611:
578:
551:
524:
513:{\displaystyle \mu }
504:
477:
349:
289:improve this article
161:Amplification factor
1467:Duncan's Amps TDSL.
1441:About Linlai Team,
1429:"Who was GuiGuang"
1094:
1064:
1037:
1007:
977:
947:
917:
887:
854:
824:
791:
751:
693:
660:
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597:
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510:
490:
461:
329:
234:Camden, New Jersey
224:with high voltage
138:Socket connections
321:
320:
313:
212:
211:
154:class-A amplifier
112:300 mA (parallel)
92:Indirectly heated
62:Class-A amplifier
16:(Redirected from
1527:
1487:12AX7/ECC83 page
1454:
1453:
1447:
1439:
1433:
1432:
1424:
1418:
1417:
1414:"Who is Psvane?"
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1317:. 13 April 2022.
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1151:Electro-Harmonix
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500:= voltage gain,
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193:Anode resistance
147:
102:6.3 V (parallel)
42:
30:
21:
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1500:
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1482:The 12AX7 tube.
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1444:"LINLAI Global"
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1199:
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1084:
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1021:
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371:
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317:
306:
300:
297:
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274:
263:
250:
111:
110:150 mA (series)
101:
100:12.6 V (series)
45:
28:
23:
22:
15:
12:
11:
5:
1533:
1531:
1523:
1522:
1517:
1512:
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1501:
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1479:
1474:
1469:
1462:
1461:External links
1459:
1456:
1455:
1434:
1419:
1404:
1396:Sales network,
1389:
1374:
1356:
1338:
1320:
1312:killerrig.com,
1305:
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1285:Vintage Guitar
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107:Heater current
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97:Heater voltage
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50:Classification
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2:
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1496:
1495:JJ Electronic
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1426:Rachel Zhang,
1423:
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1411:Rachel Zhang,
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1170:JJ Electronic
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1129:Manufacturers
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1111:
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278:This section
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242:
237:
235:
232:engineers in
231:
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208:
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199:
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183:
179:
177:Anode current
175:
171:
169:Anode voltage
167:
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159:
155:
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141:
136:
132:
128:
125:1 per section
124:
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109:
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99:
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82:
78:
74:
70:
66:
63:
60:
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52:
48:
41:
36:
31:
19:
1510:Vacuum tubes
1437:
1422:
1407:
1392:
1377:
1368:
1359:
1350:
1341:
1332:
1323:
1308:
1294:
1283:
1277:
1263:
1153:, Svetlana,
1132:
1123:
1119:
1107:
867:
763:
733:
729:microphonics
713:
705:
472:
345:
341:
330:
307:
298:
287:Please help
282:verification
279:
251:
238:
214:
213:
185:Bias voltage
89:Cathode type
261:Application
222:vacuum tube
130:Max voltage
53:Dual triode
1504:Categories
1255:References
1143:New Sensor
301:March 2022
201:References
1491:datasheet
508:μ
447:μ
441:×
369:×
366:μ
156:operation
1243:See also
1166:Slovakia
1155:Tung-Sol
864:= 37-41)
834:= 17-20)
152:Typical
76:Diameter
1188:Gallery
1159:Mullard
1077:12U7 (
990:12DT7 (
960:12DF7 (
248:History
196:62.5 kΩ
84:Cathode
58:Service
1489:(with
1288:: 114.
1161:brands
1157:, and
1147:Sovtek
1139:Russia
1017:= 100)
473:Where
337:Miller
333:triode
219:triode
180:1.2 mA
68:Height
1493:) at
1177:China
1114:noise
1074:= 17)
957:= 60)
868:12AX7
805:12AU7
801:= 60)
772:12AT7
725:12AV7
721:12AU7
717:12AT7
215:12AX7
172:250 V
133:300 V
117:Anode
44:12AX7
33:12AX7
18:ECC83
255:6SQ7
241:6SL7
226:gain
188:â2 V
1520:RCA
1179::
1175:In
1168::
1164:In
1141::
1137:In
291:by
230:RCA
164:100
1506::
1367:.
1349:.
1331:.
1149:,
723:,
719:,
703:.
1452:.
1446:.
1431:.
1416:.
1401:.
1386:.
1371:.
1353:.
1335:.
1302:.
1271:.
1090:v
1086:A
1060:v
1056:A
1033:v
1029:A
1003:v
999:A
973:v
969:A
943:v
939:A
913:v
909:A
883:v
879:A
850:v
846:A
820:v
816:A
787:v
783:A
747:v
743:A
691:0
688:=
683:K
679:R
656:d
653:a
650:o
647:l
643:R
620:P
616:R
593:t
590:o
587:t
583:R
560:K
556:R
533:P
529:r
486:v
482:A
459:)
456:)
453:1
450:+
444:(
436:K
432:R
428:(
425:+
420:t
417:o
414:t
410:R
406:+
401:P
397:r
393:(
389:/
383:t
380:o
377:t
373:R
363:=
358:v
354:A
314:)
308:(
303:)
299:(
285:.
20:)
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