I have a synth module–a Roland JV-1010 to be exact–that uses a wall-wart-style DC power transformer, bulky in the unfortunate manner of its ilk.
I have a smaller power supply that will allow me to squeeze an extra space out of my power strip. But the synth wants to see 12VDC 400 mA, and this one is only 300 mA.
I have, perhaps foolishly, tested it and it seems to work fine. But if I use it regularly, will I be shortening the instrument’s life span?