[MrFixr55]

Hi Peter,

That is an outstanding explanation!!!! I knew that RCA described 2nd order harmonic distortion as "pleasant", but never knew that the tolerance for higher orders of distortion were actually quantified and documented.

In looking at the 655 circuit, it appears to be a Class AB. The power and distortion specs that I quoted were from the 1937 RCA Receiving Tube Manual.

RCA (and others, I guess) tended to favor Class B Push Pull Audio for a while, But I have not heard one that I like. This includes the Crosley 02CA with twin 6AC5s driven by cathode follower 6J5s, an RCA 5BT (Type 19 Class B Push Pull driven by a correctly biased Type 30) and RCA 6BT (2 49s in Class B Push Pull driven by the same Type 30 Circuit as the 5BT. I find both of these to be harsh, especially when listening to classical music, even injected into the phono input, eliminating the distortion caused by radio itself.

I am a big fan of classical and sacred music but have no talent for performing it. Our local Roman Catholic parish has a lovely music ministry, a gifted music director, a 1200 pipe Chancel organ and a 4000 pipe Grand organ Either or both organs can be played from either console. We have choral concerts every spring with an orchestra, so I get to hear a good amount of live music. Our Chorus has a repertoire that spans from medieval to modern with a lot of Bach, Mozart, Palestrina, De La Victoria, Faure, Purcell, Mendelson, Rhineberger, etc. No matter how good the electronics, tube, transistor, OpAmp or digital, there is nothing compared to being there!

You and your country remain in my prayers.

Kind Regards,

John

John