6L6
6L6 has no equivalent designation confirmed by the archive. Completed sales put the typical price at $32.97 per tube.
The 6L6 is an octal 7-pin tube. In the 6L6-G version, pin 4 is Grid No. 2, pin 5 is Grid No. 1, and pin 7 is the heater. The 6L6-G can be mounted in any position.
Ratings
The 6L6 has a maximum plate voltage rating of 360 volts and a maximum grid-No. 2 (screen) voltage rating of 270 volts. The maximum grid-No. 2 input is 2.5 watts, and the maximum plate dissipation is 19 watts. The peak heater-cathode voltage rating is 180 volts maximum, whether the heater is negative or positive with respect to the cathode. The maximum grid-No. 1 circuit resistance is 0.1 megohm for fixed-bias operation and 0.5 megohm for cathode-bias operation.
Characteristics
Per tube, the 6L6 has a plate resistance of approximately 22500 ohms and a transconductance of approximately 5500 micromhos. In triode connection, with grid No. 2 connected to the plate, the 6L6 can be used as an AF power amplifier.
Applications
The 6L6 and 6L6-G are intended for use as push-pull AF power amplifiers in class AB1 or class AB2 operation. Typical operating conditions for push-pull class AB1 with a plate voltage of 360 volts and a grid-No. 2 voltage of 270 volts include a grid-No. 1 voltage of -22.5 volts in fixed-bias operation, or a cathode-bias resistor of 248 ohms. Under these conditions, the effective load resistance (plate to plate) ranges from 3800 to 6600 ohms in fixed-bias operation and is 9000 ohms in cathode-bias operation. The zero-signal plate current is 88 mA, and the max-signal plate current is 132 mA in fixed-bias operation or 100 mA in cathode-bias operation. Total harmonic distortion ranges from 2 to 9 percent in fixed-bias operation, and max-signal power output ranges from 18 to 26.5 watts in fixed-bias operation or is 24.5 watts in cathode-bias operation.
Typical operating conditions are also given for lower plate voltages. At a plate voltage of 250 or 270 volts with the grid-No. 2 at the same voltage, fixed-bias grid-No. 1 voltages are -16 or -17.5 volts, and cathode-bias operation uses a resistor of 124 ohms. The effective load resistance (plate to plate) is 5000 ohms. At these conditions, zero-signal plate current is 120 or 134 mA, and max-signal plate current is 140 or 155 mA in fixed-bias operation, or 130 or 145 mA in cathode-bias operation. Total harmonic distortion is 2 percent, and max-signal power output is 14.5 or 17.5 watts in fixed-bias operation, or 13.8 or 18.5 watts in cathode-bias operation.
| Measure | Per tube |
|---|---|
| Median | $32.97 |
| Typical range (25th–75th) | $23.00 – $50.90 |
| Most sales (10th–90th) | $14.95 – $81.95 |
| Extremes incl. outliers | $3.89 – $309.95 |
| Completed sales | 378 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| RCA | $45.00 | $26.32 – $70.00 | 91 |
| Sylvania | $30.00 | $24.00 – $40.00 | 80 |
| GE | $32.50 | $27.89 – $44.83 | 37 |
| Tung-Sol | $33.37 | $25.44 – $43.00 | 24 |
| JJ | $32.24 | $27.50 – $35.98 | 13 |
| Philips | $46.99 | $39.99 – $54.99 | 9 |
| Sovtek | $28.74 | $20.00 – $32.50 | 6 |
| Westinghouse | $22.98 | $19.45 – $25.86 | 5 |
| Mullard | $51.77 | $42.49 – $156.07 | 4 |
| Marconi | $24.25 | $23.00 – $26.45 | 4 |
| Fender | $33.98 | $27.40 – $127.99 | 3 |
| Electro-Harmonix | $23.50 | $10.50 – $25.00 | 3 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $36.20 | 113 |
| used | $30.66 | 183 |
| current | $34.91 | 47 |
Per-tube prices from completed sales, 2021-10-17 to 2026-10-18. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 6L6, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| RCA (HB3) | 6L6 | PDF (542 KB) |
| RCA | 6L6 | PDF (255 KB) |
| Sylvania | 6L6 | PDF (140 KB) |
| RFT | 6L6 | PDF (128 KB) |
Documents held here and used to write this page.
- 6L6, 6L6-G
2 further designations appear alongside 6L6 in the literature but below the evidence threshold used here, so they are not listed as equivalent.