UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Low noise amplification with mulitple valves

Lucien Nunes · 24th Nov 2010, 9:47 pm

Is it not therefore true to say that where there is enough input current available to drive many valves in parallel instead of one, the parallel configuration has better SNR mainly on account of having less of an impedance mismatch into the grid circuit than the single valve configuration?

If that mismatch were not there, i.e. if the source were able to drive exactly one grid without excessive loading, then for the same input power the amplitude at the grid would be correspondingly increased and the SNR proportionally lowered for the single valve case.

Lucien

24th Nov 2010, 9:47 pm	#4
Lucien Nunes Rest in Peace Join Date: Apr 2008 Location: London, UK. Posts: 2,508	Re: Low noise amplification with mulitple valves Is it not therefore true to say that where there is enough input current available to drive many valves in parallel instead of one, the parallel configuration has better SNR mainly on account of having less of an impedance mismatch into the grid circuit than the single valve configuration? If that mismatch were not there, i.e. if the source were able to drive exactly one grid without excessive loading, then for the same input power the amplitude at the grid would be correspondingly increased and the SNR proportionally lowered for the single valve case. Lucien