Tube life is unpredictable enough that its understandable to be told 4 months is the tubes. But only if its a time or two. In normal use, couple hours a day, tubes should last a few years. More use, higher volume, less tube life. To get it down to 4 months though would be running high levels pretty much all day. Guess you could do this if you have inefficient speakers and listen a lot. Not saying that's what it is, just filling you in on what to expect from a guy with a couple decades experience with tube amps. More likely its like the others said, they're biased too hot, and the service will fix it.
You really should name the amp and age and details. Its never derogatory to say what actually happened with a component. It helps us all know what to expect. If its a quality product people will know and say wow that's unusual. If its not people will probably know that too and say yeah as expected and more people will know to avoid. In other words its helpful to know.
Not to mention if the place you sent it knows there's like a hundred eyes on this you are more likely to get good service. So there really is no reason not to say, and every reason to fill us all in.
