New EVH 5150III LBX-S

[Rex_Rocker]

https://www.evhgear.com/gear/amplifiers/head/5150iii-15w-lbx-s-head/2256020000

First thoughts: Green and red channel? Yes, please! The cage lights up with the color of the channel! Cool! External bias test points! Yusss!

Second thoughts: Only four preamp tubes? Either there's some solid state stuff going on somewhere (the OG LBX and LBX have MOSFET-driven tone stacks), or the red channel isn't really the six-gain-stage red channel from the LBX 1. I honestly wouldn't mind if they made the FX loop solid state, but if the FX loop is tube-driven like it is on the LBX II, not sure what they're doing with the red channel here?

Either way, would love to try one. I absolutely adore my LBX, and I miss my old LBX II.

 

[Phantasmagoria]

Re: New EVH 5150III LBX-S

I don't think the number of preamp tubes makes that big of a deal. My Laboga The beast 30 Plus has just two 12AX7's (and no solid state clipping as specified by Adam Laboga) and it's the gainiest high gain amp I own. Up there with my SS AMT Stonehead, if not a bit gainier. even...

 

[Rex_Rocker]

Re: New EVH 5150III LBX-S

Yeah, not saying it's not going to have enough gain or not be good, but I do think that if it isn't 6 gain stages, it isn't going to be the same core sound as the red channel as on all the rest of the EVH lineup. I think the over-the-top amount of gain stages in the red channel of the EVH stuff is not about the amount of gain (which is pretty crazy in itself), but more about the squishy ultra modern voicing that's liquid, sustaining, saturated, but still tight. Almost like a TS-boosted amp without actually having to use a TS.

The LBX II's blue channel is supposedly based off the blue channel on the Stealth, which is higher gain than the standard's blue channel. It has 4 gain stages, so two preamp tubes for distortion, a solid-state tone stack, a tube-buffered FX loop send and return, and the PI, making it 4 AX7's, AFAIK. It sounded nice when I had it. It definitely had enough gain, but it wasn't the red channel. That's why I traded it for the LBX 1. It's not better or worse, but it isn't exactly what I wanted out of an EVH amp (though, I must admit, it would be nice to have that blue channel instead of the wimpy blue channel on the LBX 1).

Then again, this is just me theorizing and nerding out. I'm sure it will sound nice.

 

[Phantasmagoria]

Re: New EVH 5150III LBX-S

Apparently you can you use the two halves of a 12AX7 as individual seperate gain stages or something like that..so 4 tubes could give you 6 (or more..up to 8 lol) gain stages. I know that's what's been done with the Laboga Beast. Who knows, they might have done something like that with this LBX-S as well (?) in which case it shouldn't really be that different from before gain-wise. But yeah.. just guessing myself

 

[devastone]

Re: New EVH 5150III LBX-S

Yes, each 12AX7 had 2 amplifier sections in it, so it could still have 6 gain stages and still have a 12AX7 for the PI. I'm sure they are doing some SS/FET stuff just to get it to fit in that small of a box.

 

[Rex_Rocker]

Re: New EVH 5150III LBX-S

Yeah, each 12AX7 has two triodes within. AFAIK, the LBX 1 and 2 have tube buffered FX loop send and returns, so there goes an AX7. Then the PI, that's another AX7.

I don't think there is a schematic available for the LBX 2, but on the LBX 1, the schematic shows the six halves of the first three tubes are used for gain staging on the red channel (the EVH lineup's red channels are the only examples I can think of that have that many distortion stages), then the tone stack driver is an FET (in the LBX 1 and maybe the 2, not in the rest of the EVH stuff), and then the FX loop uses a whole tube, and the PI does as well. So yes, even though the LBX 1 and 2 have 5 and 4 tubes respectively (which is more than many preamps in full-size amps anyway), there is some solid state wizardry going on in the signal path, probably because the chassis is pretty crammed as it is, or maybe because the extra tube would be too demanding on the small power transformer? Who knows.

I guess what I'm curious about is where they decided to go solid state on the LBX-S. If the tone stack driver is like on the 1 and 2, and either the FX loop (which what I'd hope) or one of the gain stages.