I have had the exact same tubes in my LARRY DINO now for over 3 1/2 years,
Every once in a while, I take them out and test them…
They haven’t even changed one percent, None of them…it’s weird,
I have other amplifiers that eat tubes, like the Bogner 100B’s.
Larry must have everything running at perfect optimum levels for tone and longevity.
I crank it many hours a week, so it’s not as if a baby it…I really don’t understand it.
But it’s all good?
The key word is "parasitic oscillation"
You can't hear it, even not your dog - and the speakers anyway don't transfer such high frequencies.
But they are there.
In 4 of 5 of all old Marshall amps, in Hiwatt's, Orange's, aso.
And they strain the power tubes additionally sometimes not insignificant.
The reason is a sometimes terrifying disadvantageous lead dress.
They haven't spent enough attention to the lead dress, disregarding the fact, that each lead is a sender and a receiver of sometimes huge stray fields.
Later amp builder, especially those who are using Marshall style amp chassis for their builds often simply have adapted it.
Maybe by thinking: "If Marshall has wired it this way, it must be right"?
But no! Many later amp builder obviously simply have copied & pasted the mistakes of the famous antetypes?
Those amp builders, who have read all my 4,650 posts at forum.metropoulos.net/ should know, how to do it 'right'
Good night! (02:10 am here in Germany)
