Music man 212HD - 130 , noises

Hello,need help.
When I switch the amp on,it starts sounding like crumpling up paper, in spite of volumes are turned down to zero. As soon as the tubes are warm that crumple noise disappears.
What does that come from ? Can it be because I changed the 4 tubes to EL 34 BSTR ?

That sounds like a noisy resistor, cap (power supply probably) or tube.
If substituting tubes doesn't effect it then it needs to go to the shop for some quality "bench time".

Thanks Steve
It's good to know there is someone who can give advice.
Karl-H.

Do you have the standby switch in "off" mode? It's supposed to have some time to warm up the tubes.