Hi all, 
        I have a Fender Bassman 135. It has a line out/ recording output at the back. please can someone tell me if this is a pre-amplified signal? I am wondering if using this output will give me a valve soumd through the PA ?If so do I really need a DI box ? can i not plug it straight into our PA desk?  
 
        Hired PA's in the past have plugged the DI box into the amp input. 
 
                   Thanks for help.