Oh yes.. forgot the NFB part. Well, it does have negative feedback and oodles of it via R4, as do most solid state linear amplifiers. The proportion of feedback, hence the overall signal voltage gain and lower bandwidth limit of the amplifier, is set by the voltage divider formed with R3+C2. Unlike tube circuit NFB though, its not an arbitrary feature with solid state because there needs to be much more of it plus much more raw gain to begin with so the amplifier's stability is always at higher risk - like when components age or are the wrong type or different values are substituted.
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I just read this article that associated Damping Factor (DF) with NFB: Damping Factor Explained. And I never thought of looking at the component image for the BOM! I think at this point the speaker cabinet needs to be completed. As far as removing components, I'll save that for another point in time.
Since my last post, it was determined a diode was absolutely necessary on each rail. I have to see what kind of droop it has already.
During experimentation with a capacitor multiplier to get rid of the SMPS noise, it was noticed that one unit got very hot compared with the other. Swapping positions, the other unit did the same thing on the same rail. On another occasion, the opposite rail unit got hot. So the multiplier was dumped to eliminate the complication, and just a simple capacitor string was used . Some headroom was gained in the process, since the 3V drop was eliminated.
The units tied together for a common (electronics ground) created the situation where the two units with their independent control circuits were sensing each other causing one or the other to shoulder more of the load, yet the current on each rail remained identical according to the Fluke 87. Another manufacturer, Traco, indicates that diodes arre only needed when paralleling units, and the dual rail setup needed none. This is not true with the XP Power units before me. The diodes cured that problem. Now there is a 0.7V drop instead.
As I was scanning the schematic to see how a droop mod could be added, I could not help wondering what kind of person could come up with such a contrivance. I guess he, and the others, were driven like I am, albeit in a different realm.
The idea, if I am correct about getting the desired characteristic (if needed), is to add two, very small value resistors in series, and connect the junction to the part in the gain circuit that is out-of-phase with the negative speaker terminal.
I got an idea for the speaker arrangement planned from an article about a hybrid (tube pre/SS power) guitar combo amp which uses an angled baffle plate. The writers state it reduces destructive interference in the higher frequencies at long distances. They even included some sonic images to prove it. In case anyone was wondering how my head works, I would get along with those fellows. One of their design criterion was to reduce overall weight, as is the case with my contraption. Article attached (web link disappeared). View attachment Project 7 Guitar Amp Hybrid.pdf
Since my last post, it was determined a diode was absolutely necessary on each rail. I have to see what kind of droop it has already.
During experimentation with a capacitor multiplier to get rid of the SMPS noise, it was noticed that one unit got very hot compared with the other. Swapping positions, the other unit did the same thing on the same rail. On another occasion, the opposite rail unit got hot. So the multiplier was dumped to eliminate the complication, and just a simple capacitor string was used . Some headroom was gained in the process, since the 3V drop was eliminated.
The units tied together for a common (electronics ground) created the situation where the two units with their independent control circuits were sensing each other causing one or the other to shoulder more of the load, yet the current on each rail remained identical according to the Fluke 87. Another manufacturer, Traco, indicates that diodes arre only needed when paralleling units, and the dual rail setup needed none. This is not true with the XP Power units before me. The diodes cured that problem. Now there is a 0.7V drop instead.
As I was scanning the schematic to see how a droop mod could be added, I could not help wondering what kind of person could come up with such a contrivance. I guess he, and the others, were driven like I am, albeit in a different realm.
The idea, if I am correct about getting the desired characteristic (if needed), is to add two, very small value resistors in series, and connect the junction to the part in the gain circuit that is out-of-phase with the negative speaker terminal.
I got an idea for the speaker arrangement planned from an article about a hybrid (tube pre/SS power) guitar combo amp which uses an angled baffle plate. The writers state it reduces destructive interference in the higher frequencies at long distances. They even included some sonic images to prove it. In case anyone was wondering how my head works, I would get along with those fellows. One of their design criterion was to reduce overall weight, as is the case with my contraption. Article attached (web link disappeared). View attachment Project 7 Guitar Amp Hybrid.pdf
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I think you're off on a tangent with that college paper. Its aim is to demonstrate that the author can conduct, record, analyse and present a complete and worthy technical project document but whether the project itself has any real merit for its purpose could well be in doubt. Let's just say there's a lot of posturing and formality and it could be put simply with pics and fewer pages for us DIYs.
FWIW, damping factor is very high with any decent, direct coupled, solid state power amplifier but it certainly can be a problem for tubes in hi-fi applications, with their impedance characteristics and the quality of their output transformers (or not, depending on how much you like the sound effects).
Anyway, I'd discuss your project(s) further in the Instruments and Amplifiers forum where others with similar ideas and plans will have a more focused perspective and maybe some helpful experience to share.
FWIW, damping factor is very high with any decent, direct coupled, solid state power amplifier but it certainly can be a problem for tubes in hi-fi applications, with their impedance characteristics and the quality of their output transformers (or not, depending on how much you like the sound effects).
Anyway, I'd discuss your project(s) further in the Instruments and Amplifiers forum where others with similar ideas and plans will have a more focused perspective and maybe some helpful experience to share.