Marshall JVM vs 2203RI poweramp question

[Fragle]

Just a random question that popped up in my mind......from what i've gathered, the JVM and the re-issue 2203 share the same poweramp, OT and so on.
now, the thing is, i own them both....and as far as output volume goes, there's simply no comparison. i frequently run the JVM around 5/10....it's loud, but not earsplitting loud. and tbh it doesn't get that much louder if you turn it all the way up, you only start to get more poweramp distortion.
the 2203 on the other hand has got to be one of the loudest amps ever produced. only the hiwatt custom 100 kills it in terms of volume....even with 2 tubes pulled, running at 50w, i can barely get the volume past 3,5, it's just too much.

so....how can that be, if they indeed share the same poweramp design?

 

[drew_drummer]

The JVM has channel volumes as well as master volumes - if you think of these as attenuators, to make a fair comparison between both amps, you'd need to have the channel volumes fully cranked, and then use the master volume. I'm pretty sure you'll find they're of a similar loudness once you do this.