So i was jamming out to some 80s metal on my Marshall JVM the other night when suddenly, i hear a loud "POP" coming from the amp followed by an inherent hum (similar to the sound when you pull the guitar cable out whilst the amp was on). As soon as this happened, i quickly put the amp on standby and turned it off. Now this is where the problem starts for me. I turn on the amp to check if everything is in working order, and it is. The amp starts up fine with no pop, no hum. However, i kind of notice that the guitar sounds a little bit thinner (lacking some bass frequencies, and punch). At this point, i am wondering if something really bad did happened to the amp after that "pop", or if it is just my imagination since i have been tweaking the amp's setting the day before and am quite an OCD person. The "pop and hum" came in approximately after i turned the amp on for less than 10 mins. I am hoping that it is just my imagination and would like your opinion on the situation in regards to the following questions. 1. Does anyone know what this pop and hum might be, and have anyone ever had a similar experience to this? 2. Because i tried comparing the level and sound of the Marshall to another ENGL i have to see if there is a difference, i noticed that the level and dynamics/punch were quite similar, and with this being said, could it be something that is caused by bad/faulty wiring in the guitar itself? The amp is only 5 months old and was bought brand new..so i doubt the problem is with bad/old tubes although these things do happen. I look forward to hearing some advice and opinions from you!