From a reputable source!
Beware! There are a lot of sources for amplifier tubes and name brand alone does not assure you are getting a quality tube.
You should as a general rule avoid the internet tube warehouse type places because often the tubes they sell are seconds of inferior quality. The initial cost may be cheaper, but the repair bill when they take your amp down will not be. The old adage of you get what you pay for defiantly applies here!
Music stores that sell tubes usually sell what they can buy cheap, sell cheap and make a good profit on. Their choice of what to carry is often not based on careful research. For this reason most music stores are not a good source for tube purchases & information about tubes.
Even some repair shops unfortunately will sell cheap inferior tubes because they feel their customers will kick about the price if they don’t do this. What a good repair shop will do is sell the best quality most reliable tube they can obtain at a reasonable cost to the customer. If this means sacrificing some business so be it, because a good repair shop will realize that quality and long term reliability will save the customer far more in the long run than the small amount of money they would save initially by using cheap inferior tubes!
Sorry if it sounds like I am a soap box here, but I am very passionate about providing quality service and reliable products to my customers.
I will never sell or use something at my shop that is not of good quality, poor quality parts make poor quality repairs, which makes for amplifiers failing in the middle of a gig …and that’s no good at all.
Randy Morgan ….. Owner & head technician at All Service Musical Electronics Repair