SUBJECT: Preamplifier Tubes – Type 6DJ8, ECC88, 6922, 7308AUDIBLE ILLUSIONS PREAMPLIFIER TUBES are operated within design limits specified by the tube manufacturer. *SOURCE: SYLVANIA TECHNICAL MANUAL-RECEIVING TUBES 1979 |
| MANUFACTURERS SUGGESTED | MAXIMUM | MODULUS 3A | ||
| HEATER-FILAMENT VOLTAGE | 6.3 vdc | 6.2 vdc | (1) | |
| PLATE (Supply) | 550 vdc | 250 vdc | (2) | |
| PLATE (Plate) | 130 vdc | 60 vdc | (Phono Sec.1) | (3) |
| 120 vcc | (Phono Sec.2) | (4) | ||
| PLATE (Plate) | 130 vdc | 125 vdc | (Line Stage) | (5) |
| PLATE CURRENT (Supply) | 15 mA | 10.3 mA | (Line Stage) (Triode Pair) |
(6) |
| PLATE DISSIPATION | 1.8 watts | .04w | (Phono Sec.1) | (7) |
| .6w | (Phono Sec.2) | (8) | ||
| 1.29w | (Line Stage) (Triode Pair) |
(9) |
(1) Measurement taken at each tube
(2) Measurement taken at output of regulated power supply
(3) Measurement taken at 1st stage plate resistor
(4) Measurement taken at 2nd stage plate resistor
(5) Measurement taken at plate resistor
(6) Measurement taken at cathode resistor
(7) Measurement taken at 1st stage plate resistor
(8) Measurement taken at 2nd stage plate resistor
(9) Measurement taken at cathode resistor
*Note: Audible Illusions currently uses a Russian manufacture 6922 dual triode tube. The voltage-current maximum rating for this tube is somewhat higher than 6DJ8, ECC88 or 7308 tubes.