...As parts age their values drift...some more than others. Transformers age as well and since the power transformer supplies the very power your speakers draw while the output transformer couples that power to the speaker, these would have a much more dramatic effect. Power transformers play a part in how "stiff" the power supply is which affects the dynamic response of the amp...
...The environmental conditions of the listening environment affect what we hear right along with speaker type/age, speaker placement, size/shape of the listening environment, air density/volume within said listening environment, etc etc. On top of that wall voltage has a drastic effect on what you hear and we all know that can vary widely depending on time of day.
...People have the tendency to believe that the human ear can somehow hear everything that's happening electrically in an amp circuit. Just because a scope would see it doesn't mean you'll always hear it. This is why we techs use scopes to troubleshoot things...they can display things that are happening electrically that we cannot hear.
...the human ear is a pretty crude listening device that cannot always be trusted. We don't hear "flat" and the frequency response of our hearing changes with perceivable volume. Our hearing is less sensitive to lows/highs at low volume levels while becoming flatter as perceivable volume is increased.
You guys still beating up 40watter?
I always thought the SOZOs were for older style circuits such as the NMV Marshalls.......but who really knows.
Twin.......do you still have/use your SOZO & Silver Mica - 2204 amp? http://www.marshallforum.com/marshall-amps/22999-best-marshall-you-heard-2010-a.html
Hey Tony, why don't you email him and ask him?
Mark
The cheapest and easiest way to make your amp sound better is to change the strings on your guitar. The next thing to do, and the most difficult, is learning to play better. Not that good gear isn't important, but once you have a good guitar and a good amp, most of the rest is in the fingers.
Ken
Absolutely! Great point Ken.