[RadioSvit]

Thanks for your prayers and support for my country, John. I also want to add a short remark about the classification of tube amplifiers, which I made for my own use. In my opinion, two-stroke amplifiers with output triodes and triodes in a differential balanced input stage have the best sound. Of course, in class A. But such amplifiers are very expensive due to the high cost and costs of winding a multi-section absolutely symmetrical output transformer. Such amplifiers most accurately reproduce the sound and introduce the least distortion, and therefore are suitable for all genres of music, especially for symphonic classics.
I consider it the next in terms of accuracy and quality of sound reproduction
an amplifier with a single-cycle output stage on a triode and a driver stage according to the mu-repeater scheme. But such amplifiers are also very expensive due to the high cost and costs of winding the multi-section output transformer. Single-section output transformers from radio receivers are not suitable for such amplifiers. Such amplifiers are best suited for playing blues and jazz.
Even lower I would place the pushpool on the pentodes in the ultra-linear connection. This is already a much cheaper option, although it is very powerful. The amplifier on class A pentodes is even lower in quality, of course without negative feedback.
Well, then there are only push-pulls on pentodes in classes AB and B in various variations of the depth of Reverse Negative Feedback, from which there is little pleasure in listening.

PS. Oops. I caught myself thinking that my story about amplifiers has nothing to do with my colleague's topic about Philco ... If it interferes, I will ask the admins to move these three posts to a separate new thread, in which we can discuss the quality of low-frequency amplifiers of various radio receivers and sound reproduction systems .