Re: Concrete Tornado
At the frequencies and outputs Ferranti were used to dealing with they may have had a point, my understanding is that it took a long time for solid state electronics to catch up with vacuum tubes for high (kilowatts) power, and high (gigahertz) frequency applications.
And as at least one other poster has suggested, there’s really no substitute for a quartet of gently simmering EL34s to funnel your guitar licks through... :-)