Excellent question, by purely listening I at least know itís the front cylinder. On next start I will do that. Judging by that question Iím guessing both make similar sound?
They're very similar, but I don't have a ton of in-person experience with these sorts of noises out of the VN750. On just about any car engine, I could diagnose from 20ft away.
Mine makes a very slight tensioner tap, when cold, that goes away in the first minute. Yours sounds like an amplified version of that.
I'm a fan of the $5 mechanic's stethoscope at Harbor Freight, have one now but rarely get to use it. I've only used it on the Vulcan so I know what normal sounds like. It sounds downright scary. I can hear every rocker, cam chain, guide, and roller with the stethoscope. One other time I used it to find a noisy serpentine idler.
If you find one tensioner where you can feel the tap, you've pinpointed the problem. You shouldn't feel a rocker tapping at the tensioner body unless it was really extreme, like almost breaking through the valve cover.