I have been looking at getting a U5 because they sound amazing for bass guitar but I was skeptical about how it would work with the old doghouse as I have found mixed reviews with DB. The jazz group I play in also is the band for a local burlesque troupe so we played last night before The Rocky Horror Picture Show. At the moment I have an SWR California Blonde 1x12 combo and a K&K bass max. I ran the U5 in front of the amp and I was shocked at the difference in sound. The SWR is a decent sounding amp but nothing to write home about, and while the bass max is a very affordable and reliable pickup I dont think it is the best sounding pickup around. With the U5 my bass sounded absolutely fantastic. I play a nice sounding Solano 5 string and the Avalon brought out the acoustic tone of the bass. Even at a pretty high volume the amp sounded just like my bass. Even better the arco sound was attractive and singing. On the lower notes there was still some amount of piezo "grind" but the sound was very usable. Just as a test I pulled the U5 and ran straight into the amp and was immediately rewarded with the same mediocre, dumpy tone that I always fight with. I am now sold. At 500$ to 600$ the U5 is worth every penny. Not to mention that the Avalon sounds unbelievable for bass guitar. Definitely worth a look.