I bought two of these preamps in the last year on the recommendation of a friend. They are modelled on API's but fraction of the price. I dont have an API to compare them to but against my built in pres on my focusrite they are much warmer smoother and have a bit more mid range punch. Excellent for vocals. I found my vocals were thicker sounding and had more presence. Sound great on guitars too acoustic and electric. Good all round preamp. Clean sound with a nice bit of analogue warmth thanks to the transformer.