How was it recorded back then, straight to cassette, a "ghetto blaster" sort of deal? If so, there won't be much you can do. Many portable cassette recorders of that period had AGC, Automatic Gain Control. It was a very hard limiter, not designed for subtlety. You may wish to find a multi-band compressor (I use ), and see if you can set frequency ratios to "expand" some of the rest of the program material. That may help somewhat, but this is a "polishing the turd" situation. Hissy tape, the rest of the band was further away from the mic than the drummer, lots of room echo. Good luck. edit: IQ4 is Win VST only, if that works for you.