I recently purchased a Spider Valve MKII HD100 and it is having issues with volume control. I can barely turnup the Master volume and volume on my guitar and it will rattle my walls. Guitar and cables are good, tested in my other amp. I am new to tube amps and my research indicates that for a casual player the tubes should be replaced every 1-2 years. How can you tell the age of the tubes? I fell like these are the original tubes. Amp head has a build date of 8/1/2009. All 6 tubes have clear glass. I have attached a pic of one of the tubes and all of them have the same markings. Thanks for the help.
