Marshall JVM410HJS Joe Satriani Signature Head
At a first glance, the JVM410JS may look familiar. Taking a more detailed look (and listen) though, will make you realise just how different this amp is from its stock counterpart. So, how is the JVM410JS different from the JVM410H?
Firstly, and probably most notable is the fact that the four reverb pots from the original JVM410 have now been replaced with noise gates; four noise gates no less, one for each channel and each with their own threshold. Another visible change to the front panel is the addition of a 'Mid Shift' button that can be used for both OD1 and OD2 channels, shifting the mid character of the sound to that of Joe's specification.
Tone wise, the amplifier is very different; The Clean channel is based on the aforementioned 6100 when on the green mode, with the orange and red modes being hotter variations of that tone too. The crunch channel takes the original JVM410 crunch and adds some of the popular Marshall 'AFD' circuit to it, and the OD channels are now both voiced identically, based on the JVM410 OD1 but with the gain scaled back slightly and a smoother transition between modes. The mid shift button determines the difference in mid character between the original JVM410 OD1 and OD2 tone, moving the mids from around 650khz (Mid Shift off) to around 500khz (Mid Shift on).
The rest of the JVM410JS plays out in familiar territory; the amp is still powered by EL34 valves, there are two master volumes, the supplied footswitch enables you to switch between channels, modes, 2nd master, FX loop and now also the Noise Gates and Mid Shift too. There's also full MIDI implementation on the unit.