Hey guys I'm lookin into those two amps which is better for old school thrash (Death Angel, Metallica, Testament, Anthrax, Slayer).

And what is your opinions on both amps. 🇺🇸
Although I've never played the lbx, I have the 6505mh and the 5150 iii 50w. If the lbx is anything like the 50w it's a far better amp to my ears. The 6505mh can do a sterile clean sound, but I don't think that lbx has a clean channel. I think it is just the blue and red channel from the bigger ones. The lead channel on the 5153 is much smoother and less buzzier than the 6505mh. Plus the blue channel is tight as hell with an overdrive.
The LBXII has a decent clean channel unlike the original LBX.

The EVH is a way better-sounding and higher quality amp than the 6505MH. It's got more of a brown sound than the 50 watt head, which is by no means a bad thing at all. But overall it has a way bigger and tighter low end than the Peavey  The 6505MH has a thin, raspiness to the high end and when turned up, it suffers the same problem that many other small heads have in that it has a weird upper midrange spike that cannot be dialed out with EQ'ing. In doesn't really sound like a 6505 at all. It also isn't an all-tube amp like Peavey seems to imply in their marketing either, whereas the EVH most definitely is.

The Peavey is also known to have problems with overheating due to the bias of the power valves being set way too hot at the factory. The fix is simple, but it would be better if it just didn't have that problem in the first place. It also comes with crappy stock valves while the EVH has JJ's stock.
Roses are red
Violets are blue
Omae wa mou

Quote by Axelfox
lbx easily. it's all tube. the peavey has shenanigans
Jumping on dat gear sig train.
PRS Hollowbody II / BKP Warpigs
Strandberg OS6T / BKP Aftermath
Strandberg OS7 / Lace Poopsticks
Skervesen Raptor 7FF / BKP Warpigs
Skervesen Raptor 6 NTB / BKP Juggernauts
Hapas Sludge 7 FF / Hapas Leviathan
Anderson Baritom / Motorcity Nuke BKP Sinner Anderson H2+
Warmoth Baritone / BKP Piledriver
Ibanez Rg2120x / BKP Nailbomb

Blackstar ID:Core Beam
FWIW. For the price of a new lbx you can get the 50w used. It sounds great at low levels in my apartment and has the headphone out for when I want to play late at night or want to record silently. Plus it is still a pretty compact head and easy to carry.
Let me throw the Laney IRT-Studio into the mix here as well.  It does those tones really, really well on the Rhythm channel.  It's mostly tube (1 less in the chain than the bigger IRTs), 3 channels, great cleans, good onboard reverb, and it's a USB interface with silent out, headphones, etc., etc.  

They go used for about $400 on reverb.    
Ibanez RG1570 Prestige
Jackson Kelly KE3 - MIJ (Distortion/Jazz)
Jackson DKMGT Dinky (EMG 81/85)
ESP E-II Eclipse Custom (JB/'59)
ESP LTD EC-1001FR (EMG 81/60)
Fender MIM Strat

Mesa/Boogie Dual Rectifier Roadster 212
Laney IronHeart IRT-Studio
Peavey Vypyr 30
Peavey ReValver Amp Sims
TOOOO many T.C. Electronic Pedals. . .