• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

The ultimate 300B

I met and talked with Charles Whitener about 20 years ago.
He was a pleasure to talk to.

He had purchased the original WE Lode of Tungsten Alloy for the filaments,
And the manufacturing plans (hundreds of steps) for the 300B (and other tube manufacturing plans too), and the rights to use the Western Electric's name for those tube types.
He also got the original tooling machines, and had some of the original workers too.

The difficulty of manufacturing real 100% original WE tubes is much more complicated
than you can ever imagine.
What a headache.
Vendors who quit making specific materials, retired workers, etc., etc.
Find a new worker, find a new vendor, then qualify a complete new [pre] production run, . . .

How many of you have ever worked in a technical product manufacturing facility for several years, and seen what happens?
Just sayin'
 
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The 91A rolls off very early. The last one I measured had very noticeable roll-off starting around 8kHz. This was not a problem when the 91A was designed.
This was done intentionally.
From the 100 years of cinema loudspeakers
MGM received a Technical Academy Award for the Shearer Horn System, and Western Electric incorporated it into their new 'Mirrophonic' Sound System which provided a new standard of sound quality in those theatres which could afford to re-equip.
However, thousands of exhibitors had equipment still performing well and they settled instead for equalisation which was less expensive. An engineer with 'golden ears' sat in the auditorium with a set of variable tone controls rather like a graphic equaliser. When he was satisfied that the best results were being obtained from a sample product, the frequency correction was measured and built into the amplifier system. This method was not entirely satisfactory, since many cinemas contained acoustic defects which could not be corrected by equalisation.
The Academy of Motion Picture Arts and Sciences set up a committee to study the standardisation of theatre sound equipment. A test reel was prepared containing samples of dialogue and music from the major studios, and after repeated running in several theatres a final characteristic was agreed. This limited the high frequency response to 7kHz, and was effective in reducing high frequency background noise. It became known as the Academy Curve, and was to last almost 50 years. But it was only an electrical curve measured at the amplifier output, and did not take into account loudspeaker performance or theatre acoustics.
 
The midrange is what matters in music.
Those who hear a 71A output trannie or a 618 input trannie doesn't question any longer for more highs. Those transformers shine in the midrange and there they can deliver a quality rarely heard. Thats why they are legends, not because the may have some shortcomings in the frequency range just below 20 Kcs. Its practical irrelevant for the quality of an audio amp.
You can have transformers that measure perfect well beyound 20 Kcs and still sound sterile and nasty. The knowledge to build a transformer with extraordinary qualities doesn't lie in the theoretical books alone. Much more understanding is necessary. Thats the real truth why so many just manage to build only mediocre and boring sounding transformers.
 
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Experiences and listening in audio is highly individual as every experience in life is.
Some things in life are not being delegatable. You have to make the experience for yourself.
Maybe you come to other conclusions. Fine for you, bad for someone who loves the tone and timbre of a70 year old transformer.
 
To be honest, I just see it the complete different way when it comes to electronic amplified music nowadays.
What do you get for a pricey bill and a view to live characters singing and acting?
Mostly you will hear PA trsnsistorized sound with a level that greatly damages the human ear. My last concert was approx one year ago. Never ever will I audition such a band.
All was amplified with a big PA system and they played in an old theater in Berlin.
The sound could not have been more worse and loud wasn't loud enough for the young sound engineer. I auditioned it with earplugs but they helped not much. Many weeks after the concert my ears had to rest without any noise. It was all too loud.
Now, one year behind me, I think and hope my hearing has recovered. Humans are not all the same when it comes to the ability to recover from much too loud exposure of music.
Some will tolerate it better then others. Never in this life I will audition such a band live. And I speak about singer/ songwriter, not a heavy metal band. No one could have known such a bad sounding equipment, but most of the audience fell in love with it, it seemed.
For me, to hear at home is a much much better experience. Maybe live records, they often sound better. Its so much more in the music heard with an excellent audio system.
Maybe in the 60s the sound was better as with modern PA, when they had all tube equipment, the legend of Altec/ JBL sound. But today, I hardly can imagine a more shitty sound than todays high powered PA units.
If its not the same for everyone, either they audition and search for better live bands with much improved eqipment in sound or their home audio system should improve a lot to have a better sound at home.
 
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