Quote:
Originally Posted by Maarten
Quote:
Originally Posted by stevehertz
It's all very well this talk about how valves change from the day are they made through the period in which they are used/listened to. I, and thousands of others get that, we know that! The point is, can it be HEARD?!
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This would probably depend on the circuit. I think the most important change in tube parameters is in the emission, so I think the mutual conductance would be affected as well. In a good design this is compensated with a feedback loop, but especially audiophile designs might depend a bit more on the open loop performance.
Also possibly the bias could be affected. Again, depending on the circuit. A low idle current may result in more distorsion.
P.S. I don't think we're participating in an audiophoolery thread since the thread title is more general; even if the difference can't be heard in a good audio design, it can be seen in television sets and measuring equipment. And probably heard in bad designs. |
I suppose I erroneously broadened the scope by talking about how valves change from the day are they made through the period in which they are used/listened to. The original issue was, do they need to be burned in? That being the case, then the subject of emission will not (should not!) be an issue in during an upfront period termed as burn in.