12AU7
12AU7 is also designated ECC82. Completed sales put the typical price at $29.81 per tube.
Description
The 12AU7 is a miniature indirectly heated twin triode. Each triode unit is a separate structure, with only the heater connections being common. The heater has a centre tap, enabling use in both AC and AC/DC equipment.
Characteristics
The Brimar datasheet reports an amplification factor of 19.5 and an anode impedance of 6250 ohms for the 12AU7. It also gives a mutual conductance of 3.1 mA/V and an anode current of 11.8 mA. A second set of characteristics is given with an amplification factor of 17, an anode impedance of 7700 ohms, a mutual conductance of 2.2 mA/V, and an anode current of 10.5 mA.
Applications
The 12AU7 is stated to provide a satisfactory push-pull stage for power outputs up to 1200 milliwatts. It is suitable for driving Class AB2 and Class B amplifier stages, such as a pair of 6BW6 valves or a 5763. The tube is also very suitable for use as a resistance coupled amplifier.
As an oscillator, the 12AU7 functions excellently using one unit or both units in push-pull or in parallel. In this service, the anode voltage should not exceed 300 volts and the DC grid current in the grid of either unit should not exceed 5 mA. The power output from each unit as an oscillator will be of the order of 2.5 watts maximum.
The 12AU7 may be usefully employed in television time base circuits as combined frame and line squegging oscillators. It may also be used as a driven Class C amplifier provided the ratings are not exceeded, and as a frequency multiplier. The two triode units may be used in cascade without particular precautions to avoid instability.
The Brimar datasheet includes a graph taken at an anode supply voltage of 250 volts with anode load resistances of 47,000, 100,000 and 220,000 ohms.
| Designation | Evidence | Confidence |
|---|---|---|
| ECC82 | 72 independent documents | strong |
Equivalence is asserted only where the archive's own literature states it directly, in at least 40 separate documents. Tubes that merely substitute in some circuits are not listed here.
Base B9A, viewed from below (the wiring side), pins numbered clockwise from the key. Hand-verified.
| Measure | Per tube |
|---|---|
| Median | $29.81 |
| Typical range (25th–75th) | $14.99 – $70.00 |
| Most sales (10th–90th) | $6.00 – $150.00 |
| Extremes incl. outliers | $0.65 – $887.52 |
| Completed sales | 438 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| RCA | $17.25 | $8.99 – $29.47 | 90 |
| Mullard | $64.50 | $32.49 – $144.00 | 47 |
| Telefunken | $88.00 | $60.00 – $165.83 | 45 |
| GE | $14.96 | $8.68 – $24.14 | 39 |
| Sylvania | $19.98 | $11.87 – $23.45 | 37 |
| Amperex | $83.74 | $60.00 – $160.00 | 37 |
| Tung-Sol | $23.30 | $18.00 – $36.23 | 16 |
| Westinghouse | $22.05 | $19.95 – $24.95 | 12 |
| Raytheon | $23.50 | $16.80 – $24.98 | 9 |
| Philips | $89.99 | $86.50 – $97.00 | 9 |
| Siemens | $64.00 | $40.88 – $120.00 | 7 |
| Valvo | $60.30 | $46.14 – $98.00 | 6 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $39.98 | 167 |
| used | $24.00 | 166 |
| current | $35.56 | 13 |
Per-tube prices from completed sales, 2026-03-02 to 2026-11-09. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 12AU7, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| Brimar | 12AU7 | PDF (1439 KB) |
| Tung-Sol | 12AU7 | PDF (245 KB) |
| Tesla | ECC82 | PDF (2715 KB) |
| Ei | ECC82 | PDF (620 KB) |
| Philips | ECC82 | PDF (496 KB) |
| JJ | ECC82 | PDF (234 KB) |
| Philips | ECC82 | PDF (171 KB) |
| RFT | ECC82 | PDF (94 KB) |
Documents held here and used to write this page.
- BRIMAR
- Obdobné typy: (filed under ECC82)