Atmasphere nailed one good reason (duh).
There are quite a few others, from using tubes to rectify, regulate, as differential amplifiers....none of which greatly complicate the signal path. Plus several gain stages, each very linear, are sometimes better than one gain, over stressed stage.
And a million more answers that really benefit from a fairly extensive understanding of electrical engineering....
There are quite a few others, from using tubes to rectify, regulate, as differential amplifiers....none of which greatly complicate the signal path. Plus several gain stages, each very linear, are sometimes better than one gain, over stressed stage.
And a million more answers that really benefit from a fairly extensive understanding of electrical engineering....