Shadorne wrote: Another factor could be stiffening of the compliance of your speaker drivers after months of no use ... If you listened to music on other systems ... If the room has changed or the position of equipment/istening position has changed ... Another factor that can make a real difference that will be audible is your capacitors in your equipment ...
To which I would add: Temperature changes (temperature being a parameter which is fundamental to semiconductor operation in innumerable ways, as well as one which affects most other electronic devices to some degree or another); line voltage changes; changes in the electrical noise environment (both airborne and through the power lines); on-going aging and/or burn-in of other system components; the cleaning and de-oxidization effects on connectors resulting from removing and replacing cables; for vinyl sources, the physical effects on the records of repeated re-playings, and loosening up of the cantilever suspension material in the phono cartridge; etc., etc.
The basic point being that even if our sonic perceptions are 100% accurate (which they certainly are not at least some of the time, when subtle differences are being assessed), it is very easy to attribute the difference to the wrong variable.
My own experiences have led me to believe, btw, that "stiffening of the compliance of your speaker drivers after months of no use" could very well be the most significant of these factors, if the system has not been used for a considerable period of time.
Regards,
-- Al