@73max The amount of feedback is usually given in the spec sheet.
We make zero feedback amplifiers because of some of the problems that Nelson also points out in the article I linked. In other threads, @georgehifi , you are adamant that Nelson is the guru, but in this case you don't seem to want to acknowledge him. You can't have if both ways.
Here's a little primer on how it works with feedback- you can use little or none (which means you have to rely on other means to suppress distortion). If you use a moderate amount of feedback, Bad Things happen- its use will be a degradation. But if you use a lot of feedback (20db or more) then it use is far less audible (it can start to compensate for the distortion it introduces) and so can be pretty effective. Of course, this is the tip of the iceberg; I don't like feedback because even in high amounts it makes the amp brighter than real life (so its a coloration). Since we make tube amps, I also want soft clipping, and feedback pretty well means that soft clipping isn't going to happen.
Here is another excellent article on some of the nuances of feedback design in an amplifier:
http://www.normankoren.com/Audio/FeedbackFidelity.html
When you are done with Part 1, read Part 2 as well. All the math and proofs are presented.
Bubble still up, your having illusions, or didn’t do your homework.Really?? Your prior statement which I quoted suggested that you don't understand how feedback works. And here you are doubling down.
We make zero feedback amplifiers because of some of the problems that Nelson also points out in the article I linked. In other threads, @georgehifi , you are adamant that Nelson is the guru, but in this case you don't seem to want to acknowledge him. You can't have if both ways.
Here's a little primer on how it works with feedback- you can use little or none (which means you have to rely on other means to suppress distortion). If you use a moderate amount of feedback, Bad Things happen- its use will be a degradation. But if you use a lot of feedback (20db or more) then it use is far less audible (it can start to compensate for the distortion it introduces) and so can be pretty effective. Of course, this is the tip of the iceberg; I don't like feedback because even in high amounts it makes the amp brighter than real life (so its a coloration). Since we make tube amps, I also want soft clipping, and feedback pretty well means that soft clipping isn't going to happen.
Here is another excellent article on some of the nuances of feedback design in an amplifier:
http://www.normankoren.com/Audio/FeedbackFidelity.html
When you are done with Part 1, read Part 2 as well. All the math and proofs are presented.