33,338
edits
No edit summary |
No edit summary |
||
Line 14: | Line 14: | ||
used a pair of [[5842]] tubes biased with a tail current of 10mA and a | used a pair of [[5842]] tubes biased with a tail current of 10mA and a | ||
plate-to-cathode voltage of about 100V. | plate-to-cathode voltage of about 100V. | ||
[[File:2a61 frontend.png|thumb|left|upright|Nuvistor-based front-end amplifier]] | |||
Starting with serial number 987, the front-end differential amplifier | Starting with serial number 987, the front-end differential amplifier | ||
was made with four [[7586]] nuvistor triodes: V424, V425, V524, and V525. | was made with four [[7586]] nuvistor triodes: V424, V425, V524, and V525. | ||
Line 19: | Line 21: | ||
and the parallel combination of V524 and V525 forms the other side. | and the parallel combination of V524 and V525 forms the other side. | ||
However, for purposes of thermal stability, V424 is thermally connected to V524 | However, for purposes of thermal stability, V424 is thermally connected to V524 | ||
and V425 is thermally connected to V525. | and V425 is thermally connected to V525. The tail current in the 987-and-up version is about 16mA | ||
The tail current in the 987-and-up version is about 16mA | |||
and the nuvistors have a plate-to-cathode voltage of about 70V. | and the nuvistors have a plate-to-cathode voltage of about 70V. | ||