I have an Acoustic Image Focus 1 head that has worked great for me for almost 5 years now. I'm considering getting a newer amp head to have more tonal options because the Focus is more of a neutral sounding amp. Lately when I need a more aggressive tone I use a VT bass pedal through the effect loop - and it sounds really good. Here's my question: Is there much tonal difference in the power amp sections of these new class d switching amps? Do some have more ohmph than others? I know there's a difference in tone when there's a transformer involved as with the class A or A/B amps. Or is the difference in the way the class d amps are voiced in their preamp sections? I'm wondering what to get next or if I should bother getting anything? For example, I like the features the GenzBenz shuttle max series has going for it, but will it sound that much better than what I get with my Focus/VT bass combination? Or in order to hear hear a bigger difference would I have to go with a class A or A/B amp or, what the heck, an all out tube head? I'm going to hang on to my Focus amp for backup either way. I just wonder if the class D amps have evolved enough to warrant owning a second class d amp?