I have a couple of questions about the Ampeg SVT 3-Pro Looking to pair up with an Ampeg 410 (would love to get the Ampeg Pro Neo) Currently I am using an Ampeg B 410HE love it but may be the wrong paring. Also need to replace a few knobs (not sure where) and was wondering how I should go about asking for maintenance/service on the amp head. I'm not sure what to have the tech look at or work on as a basic service to keep it working well without getting fleeced. Tubes I may need and good price. Thanks in advance!