leaking shower valve

I have a leaking tub/shower valve that only leaks when the diverter is set for a shower. It's a Delta 1700 series one handle tub/shower valve installed over a whirlpool with an access panel that can be removed from that front of the tub. I pulled the panel off and looked with a mirror up the valve wall and saw water leaking from the bottom of the valve. My question is this , " what type of connection is this? (i.e threaded, sweated) Does it feed the shower head?Either way I'm going to have to cut into the wall to fix behind it.. I just want to get an idea of what I'm up against. Anyone got any clues? Thanks

If you remove the handles and trim flange, you may be able to see exactly where the leak is. If it is one of the fittings, that will be difficult to repair without better access. Delta valves usually have male threads, which allow the option to sweat the copper instead of using female adapters. Plumbers would usually solder the connection.

I tried the flange approach and can't really see anything. Either way I must cut an access hole on the opposite side of the wall and at that point if it's only a sweated joint I'll probably fix it myself. I'm just disappointed that this is one of many flaws I'm discovering in the plumbing work we had done only three years ago when we added on. It appears that the plumbing was less than perfect. I should have suspected something when my contractor brought the plumber back three times to fix the leaking toilet. When I reached behind I realized the inlet hose wasn't even hand tight, so I fixed it. I'm much wiser now and so I keep moving forward . Thanks for your help.