I got a used JVM410H a couple of weeks ago but before I posted my thoughts I wanted to have spent some time with it. Mine is an older model from the end of 2007. It has recently been serviced and new JJ tubes have been put in. When I turned on the amp for the first time I did notice something quirky: when I press the power button sometimes the power light and other lights flicker for a second before staying on. Nothing seems wrong with the amp but I figured I'd mention it anyway. So this amp has a lot to offer tonally with it's 4 channels and 3 modes per channel! That's one of the reasons why I was so attracted to this amp. I also feel like this probably is the most modern Marshall amp in terms of high gain sounds. Since I'm mainly a rock/metal player I thought it would be right up my alley! This amp does not disappoint! The strong suits of this amp in my opinion are the OD1 and OD2 channels. Those channels alone give this amp a huge range of tones from classic to SUPER high gain and I mean SUPER haha. On the red modes with the gain at a quarter the amp has plenty of gain. It does sound good though so the red modes definitely are useful. The clean and crunch tones are really nice too but perhaps not as nice as some other Marshall amps. I feel like the clean channel is a little too 'dry' for my tastes and also with the crunch channel I kind of miss that JCM800 chime, or brightness. One of the benefits of this however is that 1. those 2 channels work very well with single coils and 2. those channels work very well with pedals! So I'm definitely not knocking those 2 channels but they sound a little bit different than I was expecting. It could change if I put some different tubes in there but I haven't had the time to try that yet. For now this will do just fine! The OD1 and OD2 channels are so tight on the orange and red modes that tube-screamers and boosts are rarely needed, even with extended range guitars and low tunings! The green modes sound great with a boost though. With all the controls in the middle I feel like OD1 orange is where the sweetspot is for me. It reminds me a little bit of how I think a Friedman HBE sounds but a little more open and Marshally. Just perfect! This mode/channel alone makes this amp worth it for me. I really LOVE the resonance control along with the presence of course. Every amp in the world could benefit from those controls... Anyway, I made an in-depth demo to put this amp through it's paces. I used 15 different guitars and I go through each channel and mode in various styles. I hope you enjoy! Who else owns one? How do you like to use it? Which channels/modes are your favorites? Any tips on getting some killer tones that you like?