How many who have purchased Valves have been able to have a Measurement done at their end shortly after receiving the Valve/ Valves to prove the Spec' referred to with the sales info is accurate?
I have got this aftersales support, and have as a result of having measurements taken and learning the Values are quite poor in relation to info supplied prior to buying. Have returned modern production Valves and Vintage Valves back to Vendors who have not known what was being sent, or selected a measurement Value that made the sale have more of an attraction.
Note: I am able to loan through being demo'd Vintage Valves that measure almost perfect as a match in each Valve Half, and this is replicated across the quantity od Valves to be used in the demo'.
As a longer term loan, I have been loaned a selection of Valves that are quite down on the manufacturers Spec' but the loan is occurring to enable the sonic of the Valve to be lived with for a period of time to assist with creating a shortlist.
I can say with total confidence a Valve which is far removed from being optimised near the Manufacturers Spec's for a measurement. Is a Valve that is more that capable of producing an End Sound that is impressive and present a good account of itself. I would also say that in certain proportions of the frequency range a Valve from a particular Brand can't be discerned for showing a great deal of difference, even when compared to the ideal model of the same Valve. In a nut shell, a poor measuring Valve will produce a End Sound, and after a period of exposure to the End Sound produced, attractive traits are able to be discovered that leaves a very good impression.
What really changes ones impression of a Poor Measuring Valve, even if a good impression is made, is when the same Valve is compared to a Valve that is measuring at very close to the Manufacturers Spec's or better and connected to the same circuit. It is only then that the Valve having been lived with for a period of time in the circuit is identified for its poor performance. A Valve close to Manufacturers Spec's or better and connected to the same circuit, will present with such an increased added attraction that the idea of maintaining it in use is the only one wanted, returning to the lesser measuring Valve is a complete no no.
When this occurs with a Valve that has already created an attraction, there is a moment of jubilation that such a discovery has been made.
Something very similar to the above happened with 300b Output Valves on a SET Power Amp', a cheap Punt Purchase to get the Amp up and running, was discovered to be a 50% Spec when measured, there were a Stop Gap Valve whilst a different New Production Purchase of a 300b Valve was being investigated.
The 50% Spec Valve was showing lots of traits that were considered attractive when the End Sound was being assessed, but it was also detected there was a shortfall in the overall performance. Appraisal from a selection of well seasoned listeners was high but with reservations, knowing more was attainable. When the New Valves arrived, the 50% Valves were thought of as being very very poor, and how had they duped so well as a performer.
How many individuals with Valves in their systems circuits are with full confidence it is actually a measuring Valve that is matching what was shown with the sales info?? Especially id the sales info was showing the Valve was near Factory Spec's.
Second Opinion from another with credentials to qualify their adeptness and evaluation formed, is a very valuable asset when spending monies that are in some cases ludicrous as an asking price.
