Help with Subway Blues, not a hun problem

When I turn the standby switch on to power down, it makes a loud pop. Is this normal for it ? It doesn’t always do it and sometimes it’s not very loud and sometimes it’s really loud.

It also buzzes a little bit until I touch the the guitar strings, then it’ll stop. Maybe that’s normal also. I don’t remember it doing it years ago.

The amp is all stock. I’ve had it since about 2003. Maybe it’s time for caps or something.

Thanks for any opinions.

Hi -- I have the Subway's bigger brother the Rocket 44 -- it generally pretty noisy on the higher gain settings but it's not noticeable in a band mix. The standby switch has nearly always popped loudly for me on shut down. With electric guitar the player is actually grounding of the circuit as the ground wire in the guitar is connected to the bridge and and hence the strings so when we touch the strings the hiss and him will usually reduce in volume quite noticeably. It's more apparent on single coil guitars. But yes filter caps do need changing every 20 years or so -- mine is from 2000 and needs to be done soon. Failing tubes are another thing that could be the source of new noises. I find the preamp in mine chews up modern 12ax7s pretty quickly.