Current amp vs Voltage amp

Ralph is what makes these forums hum.{In a good way!}Thanks again for the tips,cheers,Bob

Deadlvj,
I agree and wish other builders/designers would express their beliefs and ideas.This can lead to very informative discussions and of course different views and conclusions. There's no rule that demands we all have to agree on everything. Varying perspectives are good and reflects our individual experiences.
Regards,

"I would have loved to see some valid discussion from the other side."

I think there has been some of that. ANy specific questions or subtopics of interest?

"I agree and wish other builders/designers would express their beliefs and ideas."

There is a lot of such discussion on the various A'gon threads, but Ralph is perhaps one of the more persistent contributors.

Plus Ralph's paradigm (based around avoidance of use of NF as the best means to avoid those nasty odd order harmonics + the rest seems to stem from that), FBOFW, is more unique and "radical" and a huge minority relative to the norm these days, so I think he has more work to do to gain mind share overall accordingly. He does a fine job though and I admire his tenacity in delivering on his vision!

...plus I must add that I share the feeling expressed by many others that I do learn things of value from Ralph's posts and I thank him for that as well.

Plus Ralph's paradigm (based around avoidance of use of NF as the best means to avoid those nasty odd order harmonics + the rest seems to stem from that), FBOFW, is more unique and "radical" and a huge minority relative to the norm these days, so I think he has more work to do to gain mind share overall accordingly.

A lot of people think that this Power Paradigm thing is something of my doing. Its not. The Power Paradigm is what existed as the means of design test and measurement in the old days, pretty much everything before about 1958 or so, which EV and Mac lead the charge to move to a Voltage model.

For evidence of that I direct you to Google:
https://www.google.com/search?client=ubuntu&channel=fs&q=fisher+A-80+amplifier&ie=utf-8&oe=utf-8

The Search is for 'Fisher A-80 amplifier'. The first hit has a YouTube image, a photo of the Damping (feedback) control on the amp. If you look at it closely, you can see the range of control goes from 'Constant Voltage' to 'Constant Power' and finally 'Constant Current'.

IOW I didn't make this stuff up. FWIW it appears that there never was a current drive paradigm, although Nelson Pass has done a lot of experimentation in that area.

I also found that the means of measuring output impedance has changed- the Radiotron Designer's Handbook, which dates from the early 1950s shows a very different means of doing so, with different math, than the techniques typically used today. It did take me a while to sort out why, and the why is that as an industry we went from using power measurements to voltage measurements.

You can see this in the recording studio; older studio equipment is based on the power model, for example older microphones are often set up to drive 150 ohms, while modern mics are set up quite a bit differently!

Another way of looking at this is output impedance- many SET designers are accustom to building amps with higher output impedances and choose speakers accordingly.

This is that equipment matching conversation that all audiophiles hear about sooner or later. All I did, FWIW, was to gather these tidbits from all over and put them in the same place at the same time, and gave them a name so it would be easier to have a conversation about them. But many people have confused this with it being something I came up with, which is obviously not the case, if you look at that YouTube image.

The fact that negative feedback does what it does is also not a matter of debate. It is knowledge that has been documented since the 1950s- I refer you to Norman Crowhurst, who outlined many design parameters of audio equipment in his many writings.

(If we were able to build amplifiers with absolutely zero propagation delay as the signal propagates through the amp, then the feedback would work correctly with no ill effect. FWIW, most amplifier design theory that involves feedback actually assumes that this is the case. Unfortunately the real world does have have such examples, and being pragmatic, I figure since that is the case maybe we should look elsewhere for fidelity, since the feedback model clearly fails.)

I persist in this is only because I want to forward the art. I don't see any amplifier technology as having the answers, all amplifiers have weaknesses and tradeoffs. I am simply pointing to What Is; what you want to do with the resulting knowledge is another matter.

Now Mapman tries to make it look like I might be tilting at windmills; the evidence that I am not is very simple: If the Voltage Paradigm really worked, there would **be no vacuum tube industry**. Its really that simple. But here we are, over half a century after tubes were declared obsolete, and tubes are still being made (they are the easiest way to create an amplifier on the Power model).

FWIW normally how it works is when a superior technology replaces the prior art, the prior art dies out. How many of you still use a rotary dial on your phone?