jandidden
Responses from jandidden
| Tube Amp for Martin Logan Speakers So, to recap, what did we learn:- output impedance of a 'box' is *defined* as the change in output voltage divided by the current change that caused the voltage variation; - nfb makes the output voltage change smaller for the same current change, ... | |
| Tube Amp for Martin Logan Speakers My 2nd post above, where I say: 'The Iload is therefore 0.5 amps' should be of course 1 amp (from 8 V across 8 ohms). Duhhh. :-) | |
| Tube Amp for Martin Logan Speakers Atmasphere, I read your last post again - are you trying to say that even when nfb decreases the voltage drop due to increased current output (the Zout), that doesn't mean that the amp can all of a sudden deliver more power? If so, I fully agree. ... | |
| Tube Amp for Martin Logan Speakers Atmasphere, your conclusion that someone (certainly not me!) would think if you lower the Zout to zero in a preamp, it can effortlessly drive 4 ohms, is rather far-fetched. As I'm sure you know, Zout has NOTHING to do with what you can or cannot d... | |
| Tube Amp for Martin Logan Speakers George don't make me blush :-).Anyway. Atmaspere's statement that the INTERNAL Zout doesn't change has another side to it. It suggests that you can open up an amp and point to a component and say see, there's the output impedance. This is not the ... | |
| Tube Amp for Martin Logan Speakers Bifwynne, if I may, not trying to split any hairs, but the term SOA has a very specific meaning for ss devices. The Safe Operating Area defines the combinations of current and voltage across the device, that it can withstand for a certain time bef... | |
| Tube Amp for Martin Logan Speakers Byfwinne, yes I agree. The internal amp Zout is not changed of course.Re: increased 3rd with nfb: that has been laid to rest many years ago. Most people know the (in)famous Baxandall graph showing increased harmonics (even harmonics that were not ... | |
| Tube Amp for Martin Logan Speakers Output impedance does go down with nfb - that's a basic tenet. Easy to check: take a non-nfb amp and change the load dfrom 8 to 4 ohms. You will see that the output voltage drops a bit. Now apply nfb, do the same thing and you will see that the dr... |