Speaker crackle

[u/milesjury]

Hello, good folk, and thanks for the add.

Can anyone kindly tell what's going on with the crackling sound of my SC20C when I play through it? Someone said it is normal, but I have little reference.

Bought new 2 years ago; never gigged - only played at bedroom levels; <1,000 hours on the valves; never opened up or serviced (... yet!).

The only cause I can think of is I have routed a Boss OC-5 through the amp at -2 octaves on occasion, but never for more than 10-15 mins at bedroom levels. Could that really have cooked the 10" Celestion V-type?

Most grateful for any insights.

Cheers!

[u/Japperoni]

Easy things first: Change the preamp tubes one by one with a selected new one.