Strongly suggest you do Google and check the list of articles not allowed into China to see if anything you do plan to bring is in there or not..  Normally, on a tourist visa they do not pay too much attention to you, as long as you do not bring an excess of whatever, or fruits for example.  on a business visa is about the same, but they may take a closer look to see if what you are bringing in can be used for work. 

And if you plan to use it for generating income, please have second thoughts.  China is at present having a crackdown on illegal emigrants, like those that work without proper visa and documents, or overstay their visits, etc.  And with a business visa you can not legally work here.

To my mind there is the simpler problem of baggage allowance. Excess baggage runs at over $40 a Kilo on most airlines (more on some), and that's going to put a major hole in your financial plans, especially as the bill will be doubled when you have to return home.

Think about it. You are supposed to be a tourist or, on a business visa, attending a seminar or doing some type of promotional work. Why would you need a mixer and other "high tech" equipment? Are they supposed to believe you want to lug around all that dead weight on your way to the Great Wall or the Forbidden City? A guitar should be no problem, but all that other stuff will possibly raise some eyebrows, and then when it is confiscated, you'll be SOL.

If you want to do some night club jams (or whatever), it will be considered work, which is definitely illegal with the two visas you mentioned. Heck, even standing on the street playing the guitar with an open instrument case (where people throw in money) is considered work. Be careful, and be safe. 

hope this helps your quest.

http://beijing.usembassy-china.org.cn/china_performers.html

The guitar should not be a problem, but as to the rest of the stuff, that will be.

I would not recommend bringing the rest of the stuff, it will be confiscated.