[yestertech]

I'm investigating the idea of a project utilising multiple paralleled input valves for audio. I recall reading a study somewhere about the various dB's of noise improvement available with each doubling which, of course, I can't now find !!
The theory was along the lines that the for the total array of 2,4,8 valves in parallel, the amplified signal is coherent and hence is simply additive , whereas the noise is not, so this is only partly additive. result : better S/N ratio than with one valve alone.
Of course there are the overheads: More HT mA and more Heater A, but with modern PSU arrangements this is not that tricky ( especially as one can series operate the heaters on DC to keep all that noise at bay )
So my question is has anyone played with this, and/or know of anywhere which describes this in more detail, with any practical examples ??

Thanks

Andy