I have a 80’s Dean Baby “V” still sounds good stock old Dimarzio 1 bridge only. I had to paint it because it got damaged. Probably from the heat in SoCal.IMO,
Sometimes the wood blank chosen loses some of its voice, when contoured for a thin body or neck.
I have a bone stock 81 Dean V, that's thin and light and Roars like a 80s Thick Gibson, V or Explorer. Just primo pieces of wood were chosen for the neck and body.
I was taught, if the electric solid body doesn't sound good unplugged, the amplifier can only do so much to enhance it.
When I check out a solid body at the store, they ask me what amp would I like, I decline and evaluate it slowly and unplugged focusing how strong the wood's voice is.
I've had a gaggle of SG's. There was a '73 SG Custom I hated but other than that I've liked them all. There must be something wrong with your wiring if it sounds thin or tinny (or the bridge?); that's odd as they usually have a mid focus with more controlled high end than Les Pauls. What I can't stand are the '57 and 490 pickups - dull dead tone - no use for 'em. In fact they are about the same pickup. Right now I have a 2012 Standard I love, a little heavy with NO neck dive, a DiMarzio set I put together. Also a 2019 Junior, stock pickup, feather light, a tiny bit of neck dive - you have to make it do it on purpose. Both incredible guitars.Well over the years I’ve owned probably 5-6 Gibson SG’s and a couple epiphones. My most recent purchase is a basically new condition SG special from the mid 2000’s. Most beautiful guitar I’ve ever owned. Plug it in and it sounds like strings on a tin can. Thin extremely bright tone with no sustain. I even swapped the 490 pickups with 57 classics like i have in my Les Paul an love. Nope, still thin, shrill, and dead sounding. I guess I’m just never gonna be an SG guy. Every one I’ve had either sounds like garbage or has horrible neck dive i can’t stand. Oh well!