Rudolf Meinl makes incredible tubas by hand in Germany. I think their 3/4 CC is just about the most underrated instrument on the market.
Hirsbrunner is out of business. They sound great, but in my experience, they have intonation issues. Some HB2 tubas used rotary valves that didn't work well in hot situations. Adams bought the tooling and designs. Now, they manufacture many of their models and have made several improvements to most of them.
Miraphone tubas are great. Generally play very well in tune and sound great. Less expensive than RM and HB/Adams, but I think they're roughly equivalent in quality. When someone says that classic German sound, I hear Ron Davis playing his Miraphone 188 in my head. I really like their f tubas, they generally play well in tune and are a lot more user-friendly around the low C than many of their German counterparts.
Other brands worth considering for high-end instruments include Meinl-Weston, B&S, Alexander, Gronitz, Walter Nirschl, and Yamaha. Eastman and ZO are the best coming out of China. Instruments from these Chinese brands are generally of acceptable quality, not as good as German/Japanese instruments, but generally cost less than German/Japanese instruments. Cerveny produces instruments that are of a lesser quality than German/Japanese instruments, for a bit less money. I've played several Cerveny tubas, and I've never found one that I'd want to daily drive.
Wessex is a Jinbao dealer; they mark their products way up, but they do have a few exclusive models, albeit of the same JB quality. I will say that Wessex has some of the best quality control and customer service of the JB dealers. If you're looking for JB, there are a ton of dealers. I have found Wessex, Mack Brass, and Dillon Music to be the easiest to work with.
I'd check out a conference from the International Tuba Euphonium Association (
https://iteaonline.org/conferences/) or the Army Tuba Euphonium Workshop (
https://usarmyband.com/workshops/tuba-e ... m-workshop). There is usually a good selection of instruments to play at those conferences.