I finaly upgraded my JVM with a Mercury Magnetics choke, the MC-10H, and a Mercury Magnetics output tranny, the MAR-JVM100-O! Here are the pics: There goes my warranty!! The choke goes instead of the R106 resistor. Here you can see the difference of the two tranny's. Almost ready! The tranny didn't fit exactly, had to change the hole's! Here are the wires from the choke. Up and runnin' again!! Good things: The amp is smoother now, and reacts much better! The mids are sweeeeeet!!! The amp sounds bigger, because of the bigger and tighter lowend. And the lowend-thump is unbelievable. More harmonics. Bad things: Tranny didn't fit in the original holes. Drilling for fitting the choke. It's heavier now! Warranty is gone. The JVM is a very service-friendly amp, so it wasn't that difficult to do the mod! The output tranny was 225,- euro's and the choke 24,- euro's. And for me it was really worth it!!! The reasons why I did the mod, was that I was looking for more lowend in the OD1 and OD2 channels, and a thighter bass-response in the crunch-channel. And the feedback of the amp was not very musical to my ears. All those things are solved now for more then 100%!! Even the OD2 channel is awesome now, and reminds me of a Mesa Mark 4, but with a tighter lowend!! I was very used to my good old JCM800 2210 (alsow with MM ot and choke!), and missed some things in my JVM, like the nice feedback, and very big sound, but now the JVM can sound like that amp, and do a lot more then the JCM800!! Don't get me wrong, I always liked the JVM from the beginning, just tweaking it, like I did 21 years ago, when I bought my first Marshall, the JCM800 2210, that I still own!!