6DJ8
6DJ8 is also designated ECC88. Completed sales put the typical price at $30.00 per tube.
Description
The 6DJ8 is a high-frequency double triode with high slope, low noise, and separate cathodes, intended for input circuits of television receivers. It has an all-glass miniature envelope with a nine-pin base. The two systems are mutually shielded by internal shielding connected to a separate base pin.
Construction
The tube has indirect heating, an oxide cathode, and is designed for parallel supply with alternating or direct current. The heater voltage is 6.3 V and the heater current is 0.365 A.
Ratings
Maximum ratings include a cathode current of 25 mA, a negative grid voltage of 100 V, a grid dissipation of 0.03 W, a grid leak resistance of 1 MΩ, an effective voltage between cathode and heater of 90 V, an external resistance between cathode and heater of 20 kΩ, a cold anode voltage of 550 V, an operating anode voltage of 130 V, and an anode dissipation of 1.8 W.
Characteristics
At an anode voltage of 90 V, grid bias of −1.3 V, and anode current of 15 mA, the transconductance is 12.5 mA/V, the amplification factor is 33, and the internal resistance is approximately 2.6 kΩ. The cutoff anode current with a grid voltage of −4 V is less than 1.2 mA.
Capacitance values include a pass-through capacitance of system I of 1.4 pF, a grid-to-filament capacitance of less than 0.2 pF, a capacitance of anode II to grid, filament, and shielding of 2.8 pF, a capacitance of cathode II to grid, filament, and shielding of 6 pF, a pass-through capacitance of system II of less than 1.8 pF, a capacitance of anode II to cathode II of 0.18 pF, a capacitance of cathode II to filament of less than 3.5 pF, a capacitance of anode I to anode II of less than 0.045 pF, a capacitance of grid I to anode II of less than 0.005 pF, a capacitance of anode I to cathode, filament, and shielding of 1.8 pF, and a capacitance of grid I to cathode, filament, and shielding of 3.3 pF.
Applications
The datasheet specifies that system I is to be used as an amplifier with grounded cathode, and system II with grounded grid.
| Designation | Evidence | Confidence |
|---|---|---|
| ECC88 | 64 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.
| Measure | Per tube |
|---|---|
| Median | $30.00 |
| Typical range (25th–75th) | $19.50 – $47.50 |
| Most sales (10th–90th) | $11.82 – $104.50 |
| Extremes incl. outliers | $1.76 – $323.45 |
| Completed sales | 251 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| Amperex | $31.00 | $22.50 – $43.42 | 97 |
| Sylvania | $21.00 | $13.56 – $31.43 | 21 |
| Siemens | $84.90 | $40.95 – $134.99 | 17 |
| Mullard | $32.84 | $22.00 – $64.00 | 13 |
| RCA | $22.12 | $19.99 – $38.24 | 8 |
| Telefunken | $54.38 | $34.48 – $154.50 | 7 |
| Tesla | $42.89 | $39.00 – $48.75 | 7 |
| Philips | $39.51 | $25.00 – $98.62 | 6 |
| GE | $17.17 | $12.35 – $24.98 | 4 |
| Matsushita | $23.23 | $20.00 – $25.94 | 3 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $36.45 | 95 |
| used | $26.00 | 90 |
| current | $34.82 | 7 |
Per-tube prices from completed sales, 2026-01-30 to 2026-10-17. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for 6DJ8, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| Tesla | ECC88 | PDF (209 KB) |
| Philips | ECC88 | PDF (176 KB) |
| Philips | ECC88 | PDF (14 KB) |
Documents held here and used to write this page.
- VYSOKOFREKVENČNÍ (filed under ECC88)