6F6
6F6 has no equivalent designation confirmed by the archive. Completed sales put the typical price at $19.38 per tube.
Description
The 6F6 is a vacuum tube used in pentode connection for Class AB2 operation, and it can also be used as a triode in the input stage of a Class AB2 amplifier.
Ratings
The 6F6 has a maximum plate voltage of 375 volts. Its maximum grid No.2 (screen-grid) voltage is 285 volts, with a maximum grid No.2 input of 3.75 watts. Maximum plate dissipation is 11 watts. The maximum peak heater-cathode voltage is 90 volts, whether the heater is negative or positive with respect to the cathode.
For fixed-bias operation, the maximum grid-No.1-circuit resistance is 0.1 megohm; for cathode-bias operation, it is 0.5 megohm.
Applications
The 6F6 is used in push-pull AF power amplifier Class AB2 service. It can also be used in an AF power amplifier Class A with triode connection. In triode connection, the maximum plate voltage is 350 volts, and the maximum plate dissipation is given.
The datasheet provides typical operation characteristics for fixed-bias and cathode-bias conditions, as well as for Class A amplifier service.
| Measure | Per tube |
|---|---|
| Median | $19.38 |
| Typical range (25th–75th) | $11.55 – $22.00 |
| Most sales (10th–90th) | $5.86 – $25.50 |
| Extremes incl. outliers | $3.50 – $46.00 |
| Completed sales | 38 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| RCA | $23.49 | $20.98 – $25.50 | 8 |
| Sylvania | $18.95 | $14.84 – $46.00 | 3 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $19.75 | 13 |
| used | $15.44 | 21 |
Per-tube prices from completed sales, 2026-08-29 to 2026-09-23. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 6F6, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| RCA (HB3) | 6F6 | PDF (388 KB) |
| Tung-Sol | 6F6 | PDF (230 KB) |
| RFT | 6F6 | PDF (126 KB) |
| RCA | 6F6 | PDF (123 KB) |
| RCA | 6F6 | PDF (119 KB) |
| Sylvania | 6F6 | PDF (112 KB) |
Documents held here and used to write this page.
- 6,7,6
4 further designations appear alongside 6F6 in the literature but below the evidence threshold used here, so they are not listed as equivalent.