02-16-13: Warrenh
how do you know your tubes are beginning to fail and your music is suffering from tube deteriration?
Generally, again reffering to light bulbs, tubes either are working or not working. You will hear failure as buzzing, becoming microphonic (hearing footfalls amplified), or some other audible clue. This is unlike cartridge wear, in my experiences. While a cartridge can slowly degrade over time, the tube's decline will be rather sudden. It will sound fine one day and then the next day you'll notice a buzz or hum being generated. Then you'll have to track it down to a specific tube.
Do you bring you little babies to the tube Doctor to be tested?
No, once an audible issue has been diagnosed in a tube, the doctor's equipment cannot save it, so why bother testing it?
Also, when one of my driver tubes goes, time to replace all of them?
You can, and many people do, but you don't have to. I would say it depends on the age of the tubes. If I've had the amp for 3-5 years, and one driver tube goes, I would probably replace them all. However, if the tubes are only a few months old, I would probably just replace the defective one. Again, think of light bulbs. Let's look at a chandelier, if one bulb goes, do you replace them all? I have a chandelier with 6 bulbs, recently 3 bulbs died within a 1 month span. I changed them one at a time. Should I have just changed all 6 at once, maybe. That's a personal issue that will depend on your own personal comfort level, OCD level and financial situation.
