Context/Experience: I've been playing bass for 19 years.
I love this amplifier. The tone is very clear to a bit gritty if you crank the tube, but always very crisp. The EQ is superpowerful, each click counts. The DI is to die for, and so light! I've run it with one or two 1x12 cabs and it performs great. And so light you can do a bass rig load-out in one trip: gig bag in one arm, backpack with amp and cables on your back, 1x12 neo cab in your other hand. Tada! I've been playing this rig with a 90's style rock band (2 guitars + bass + drums + vocals, in the vein of Faith No More, Pearl Jam, etc) and the amp cuts through the two guitars with ease. I've gotten compliments on my tone from non-bassists with this rig. It's THAT good ;)
If you want a more vintage, fat tube tone, I'd suggest the Streamliner series (which I have also tested. The review is pretty much the same except the palette of available sounds is more fat and vintage-y than modern). For crispy and detailed, the Shuttle is awesome. Plus it's a company that stands behind its product, and their own engineers can be reached with any doubts about it (on talkbass.com and directly).
I am 99.9% sure my next amp will be another Genz Benz. That's how happy I am with this amp.
I just recently bought this amp after needing to upgrade from my Fender Bassman 100. The Fender was a great amp but wasn't enough power with the band I play with.
The Genz-Benz ROCKS!!! The sound is so clear and pristine. You can hear every note you play. It produces solid bass and great mids and pristine highs. With the added frequency boosts, you can really dial down and get any specific sound your looking for. And at 3.75lbs, its like you dont even own an amp, just another gig bag. Also, having it a hybrid (both tube preamp and solid state power amp) your really able to get any sound you want. Literally.
Jeff Genzler, the owner, is so nice too and he will personal answer any questions or concerns you may have. He did with me.
I would highly recommend this amp to anyone looking to join the Genz-Benz family.
Received recommendation from my bands Bass player to acquire a Genz Benz Shutlle 6.0 to add more depth to the Bass Guitar in our Church Auditorium. Did a Demo on the unit, fell immediately in love with sound that this unit added to my sound system, really made the Bass pop out of the mix. Immediately started searching internet for one to purchase. Guitar Factory sit on the Amazon site, had the unit in stock at a price better that anyone else on the internet. Did the deal, received the unit quickly and the rest has been heaven! Thank you Guitar Factory and thank you Amazon!