Weather-induced amp performance variation

Don't forget that the weather can play havoc with your sense of hearing.

Eldarthford: I guess age of the listener has much too do as age of equipment :-)

If you leave a high bias amp turned on, the device tends to stabilize temperature. It will not shift measurably unless there is a measurable shift in room temperature. Most common amps that are biased for lower level Class AB operation will undergo the greatest temperature swings, hence the bigger variations in sonics that they suffer from. Then again, going from room temperature to sustained operating temperature is still more of a swing / temperature change than going from idling but powered on up to operating temperature. On top of that, the temperature swing isn't as drastic, resulting in a slight increase in circuit stability and more consistent sonics.

Optimally, one would have a climate controlled room just for the amplifiers outside of the listening room. This would allow one to run Class A amps with enough airflow to allow them to stay cool to the touch. So long as the temperature remained consistent and the amps were adjusted in-room, both the electrical performance and sonics would be improved. I wish i was rich enough to try something like that : ) Sean
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Sean, that's easy to achieve. No controlled room -- just an airconditioner at constant temp blowing on the amps 24/7. And another room for the amps. And someone to foot the electricity bill, of course... :)

At my former work at a big Aerospace outfit (I'm retired now) air conditioning with exceptionally tight specs was always provided in labs where there were big computers and other electronic equipment. When the weather got really hot, and the office AC couldn't hack it, many people migrated from their desks to the labs. I guess management thinks that their hardware is more important than their people!