Ah...sounds like it should sound pretty good. Transistors straight into a NE5534 chip. You say you want something "smoother" I would look at replacing caps, may or may not clean up sound. I've found that is something sounds "murky" or what have you, 9 times out of 10 its bad/to many/unbiased/ electrolytic capacitors.
on another note, have you considered your microphone? What microphone are you using? I have a friend who uses the focusrite voice-master stuff, to my ears it does sound a little "clean" and even a tad unfocused, but that is without me actually using the gear, in an controlled environment...its just speculation.
If its engineered like behringer stuff, then there will be a full crop of Electros in the circuit. I wonder what would happen if you took 90% of those caps out?? I bet the circuit would work just fine, probably sounds quite a bit better too. I'm not recommending you do this though, but you could replace every capacitor with a Bi-polar equivalent. They do sound much better and I would imagine your time being well spent when you fire it up again and run some audio through it.
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