DBX 386 DRIVE INPUT

[Nofolobricity]

Hi

I have a question about DBX 386.
The drive knob on the 1st channel doesn't react. I just connect my mic or guitar and the knob doesn't add any gain. Is there a solution?

Thanks in advance!

 

[maxxevv]

Maybe one of the tubes have blown / worn out ?

 

[Nofolobricity]

Maybe one of the tubes have blown / worn out ?

I don't know. How can I be sure that it's broken?