Hello everybody, I am pretty new to tube amps. I bought a Cayin CS-55A a couple of years ago and I love the sound. However I have a big problem, the tubes have burned out twice in the last couple of years. I have used Gold lions KT88 tubes and they are not cheap. I am trying to find out what is the problem, why they burn out so fast. Like i said I am new to tubes and I have been told that this is not normal. Tubes "should" last around 3000 hours. I listen to my amp a couple of hours per day and close it after. Now I have a choice of 4-ohm or 8-ohm on my amp but my Dali Ikon 6 speakers are 6-ohm. I always put the connectors at 8-ohm on my amp. Could this be the cause of my tubes burning too fast? If I switch to 4-ohm on my amp will I lose some benefits in the sounds? Thank you in advance for your help.