What equipment will I need for testing audio production equipment?

Hello I am new to this site. I recently started going to LW Tech for electronics technology and I have about $1200 coming my way that I can only spend on stuff related to my field of study (I don't get it if i don't spend it). I want to get into designing and making my own synthesizers eventually but I also want to be able to fix any of my audio production equipment that breaks. I also want to have anything I might need for building and testing my own Alternators. I just bought a Hantek DSO5102P so I hope that will be sufficient. I am also getting a fluke multimeter through my teacher. I was thinking maybe a 20Mz function generator (how many Mhz would I really need it to be capable of producing?) with usb capabilities like the ATTEN ATF20B and what about a spectrum analyzer or frequency counter? Thanks in advanced.

Rather then a function generator, a sine wave oscillator 20 - 20kHZ with really low distortion, say 10 times lower then the distortion that you would expect to get from your products. And to match it a noise and distortion measuring set or a wave analyser (audio form of a spectrum analyser).
With a suitable load, you can then set up the rated power output by measuring the voltage with the CRO, then measure the frequency response and distortion.
Trying out synthesizers (audio I presume) only requires a CRO. Alternators require a suitable load and power measuring equipment, the CRO or DVM woulld be enough for this ( P = V^2 /R).
Frank