Won't go into all of this to nauseum but for anyone wanting an EVH 5150-III amp, the differences are huge IMO. Here is a brief few notes:
Cleans:
6L6 50 watt. Playing "Stairway to Heaven" with reverb and just sounded amazing and inspiring
EL34 50 watt "S". Clean is a Marshall clean. Even at lowest gain, almost could do ACDC crunch if hitting strings hard enough
Blue Channel:
6L6. Can crank gain and still use a boost for metal
EL34 S. Have enough Metallica type gain with gain at 9 o'clock
Red Channel: These sound very similar between the amps but obviously the S has more gain.
To my ears, the EL34 50 watt S is looser, more muddied when compared to the 6L6, and not as defined. Still a great amp but just different
In my opinion, fans of EVH's tones and more classic tones should not get the "S" Amps. The mids are cut, tons of gain even at lowest setting, etc. I found myself wanting less gain and I'm a metalhead. I'm really happy with the 6L6 50 watt. I think it is super versatile, takes pedals awesomely and sounds clearer. The EL34 50 watt S is great too but just not exactly what I want.
