EL34
EL34 is also designated 6CA7. Completed sales put the typical price at $85.47 per tube.
The EL34 is an indirectly heated power pentode with an anode dissipation of 25 W, intended for output low-frequency amplifiers in class A, AB, or B.
Construction
The EL34 has a glass envelope with a cemented octal base, the base being type K 8/18 per ČSN 35 3907. The suppressor grid is brought out to a separate pin on the base. The tube has indirect heating with an oxide cathode for parallel supply by AC or DC. The tube weighs 40 g.
Ratings
The heater requires 6.3 V at 1.5 A. The maximum anode voltage is 2000 V when cold and 800 V when operating; in triode connection the maximum anode voltage is 425 V. Maximum anode dissipation is 25 W at a control-grid voltage of 0 V, 27.5 W at maximum control-grid voltage, and 33 W in triode connection. The maximum screen-grid voltage is 800 V when cold and 425 V when operating, with a maximum screen-grid dissipation of 8 W. Maximum cathode current is 150 mA. Maximum grid-leak resistance is 700 kΩ with automatic bias in class A or AB, and 500 kΩ with fixed bias in class B. The maximum voltage between cathode and heater is 100 V, and the maximum external resistance between cathode and heater is 20 kΩ. The maximum bias for onset of positive grid current at a grid current of +0.3 μA is −1.3 V.
Capacitances
Input capacitance is 15.2 pF, output capacitance is 8.4 pF, transfer capacitance is less than 1.1 pF, control-grid-to-filament capacitance is less than 1 pF, and cathode-to-filament capacitance is 10 pF.
Notes
The TESLA datasheet for the EL34, dated 11 April 1960, states that the EL34 replaces the American type 6CA7.
| Designation | Evidence | Confidence |
|---|---|---|
| 6CA7 | 82 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 | $85.47 |
| Typical range (25th–75th) | $40.84 – $156.50 |
| Most sales (10th–90th) | $25.45 – $234.50 |
| Extremes incl. outliers | $14.80 – $801.36 |
| Completed sales | 208 |
| Brand | Median | Range | Sales |
|---|---|---|---|
| Mullard | $149.99 | $90.00 – $223.00 | 67 |
| Philips | $140.81 | $102.39 – $218.50 | 12 |
| JJ | $25.45 | $22.11 – $35.09 | 11 |
| Amperex | $121.97 | $87.99 – $236.75 | 10 |
| Sylvania | $98.75 | $62.95 – $130.00 | 9 |
| Telefunken | $100.00 | $85.95 – $230.00 | 9 |
| Svetlana | $40.90 | $32.91 – $89.61 | 9 |
| Electro-Harmonix | $30.00 | $30.00 – $32.94 | 7 |
| Sovtek | $20.00 | $18.99 – $25.99 | 6 |
| GE | $59.95 | $57.89 – $81.82 | 5 |
| Tung-Sol | $33.75 | $32.91 – $34.98 | 5 |
| Siemens | $79.50 | $49.50 – $90.03 | 5 |
| Condition | Median | Sales |
|---|---|---|
| NOS | $139.94 | 63 |
| used | $96.05 | 69 |
| current | $34.98 | 37 |
Per-tube prices from completed sales, 2024-02-01 to 2026-09-05. Matched pairs and quads are divided out. See the price index for how these move over time.
Original manufacturer datasheets for EL34, hosted by Frank Philipse's Electron Tube Data sheets.
| Manufacturer | Designation | Datasheet |
|---|---|---|
| Tesla | EL34 | PDF (2520 KB) |
| Ei | EL34 | PDF (1581 KB) |
| Brimar | EL34 | PDF (1254 KB) |
| Philips | EL34 | PDF (749 KB) |
| Mullard | EL34 | PDF (696 KB) |
| Telefunken | EL34 | PDF (504 KB) |
| Philips | EL34 | PDF (251 KB) |
| JJ | EL34 | PDF (200 KB) |
| La Radiotechnique | EL34 | PDF (173 KB) |
| Svetlana | EL34 | PDF (47 KB) |
| Tung-Sol | 6CA7 | PDF (530 KB) |
Documents held here and used to write this page.
- KONCOVÁ PENTODA
- --- TUNG-SOL ---- (filed under 6CA7)