The VAC Statement 450 iQ uses eight KT-88s. Eight X 35 = 280, but I am certain that Kevin Hayes is certain that his amplifier makes 450 watts. Are you sure you have this KT-88 story straight?
Thank you for looking out for my particular situation! The Io (well, in the future, the Callisto) will drive only one pair of interconnects -- going to the Gryphon bass towers. The pre-amp will not be dealing with a parallel load.
Hi Ron,
I'm hoping this will shed a little more light on to this topic
Two things. First, the statement regarding anode dissipation is missing two facts, and, second, anode dissipation does not tell you amplifier output power.
With respect to maximum anode dissipation ratings, Genalex (the inventor of the KT88) gave two figures: "design maximum" (35 watts), and "absolute" (42 watts). To each of these in an ultra-linear circuit you also have to add the screen dissipation. The combined ratings by Genalex are 40 and 46 watts respectively.
None of these figures tell you the output power possible in any particular amplifier. Without going into engineering discussions (such as the fact that the maximum rating is not a peak power but the integrated average over time of the entire waveform on the anode), simply consider that vintage Genalex data sheets for the KT88 show typical applications producing 100 watts RMS from two tubes. So the idea that the maximum output power is twice the dissipation rating (2 x 35 watts) is not a correct understanding of how things work.
Kevin Hayes has pointed out to me that many of the published tube specifications, such as typical power output, are either average values or what were termed "bogey" values back in the day. Individual tubes can exceed the published figures; all this varies from tube to tube. Kevin reports seeing anywhere between 95 watts and 118 watts per pair of KT88 in their basic amplifier circuit, all running within the tubes stated ratings.
Regardless of all of the tech talk, in the end what matters most is how an amplifier sounds. If specifications told the whole story we would all be listening to transistor amplifiers with 80 dB of negative feedback lol