We just built a new house with a music room and I decided to be creative and match my room with the overall look of the house.
I installed a triple set of kitchen cabinets Adel Medium Brown from Ikea and I fit them with the glass doors for their wall cabinets. On top, I have a 1.5" thick butcher block counter top (stained medium brown) also from Ikea.
The cabinets are 30" wide and they are all half open in the back. The shelves are adjustable and there is enough room for any component. Those that need more air flow, I keep on top. The whole setup is extremely stable. The look is very appealing to both of us and the cost was very reasonable.
There is a picture under White Room. Please, feel free to take a look.