Aesthetix Calypso vs. Hovland HP 100

I've heard one and had the other. I won't give an opinion, but I will say if you by a used HP100, make sure It's a later model or you'll need the Volume upgrade@$800. also, the Tape input is the most transparent and not the CD.

Could you tell me what are the pros and cons on both models (sonic wise)?

The Calypso wasn't in my system which is why I didn't give an opinion. It sounds good which is about all I can say. It was compared to an Artemis LA-1, but with some technical issues going on at the time, I once again can't give a meaningful impression.

Although I've not compared these exact two models, I have had the opportunity to hear both the Calypso and the Hovland HP200 in my system. For what its worth, IMHO the HP200 is a very clear notch above the Calypso. But it's also somewhat more expensive than the Calypso. Still, the Hovland is faster, more detailed and transparent without sacrificing musicality. In the right system it is awesome. But Calypso is a truly outstanding preamp and a comparison with the HP100 may be a much closer call. I think a choice between the two will depend largely on system synergy. Also, if you want balanced inputs you'll have to go with the Calypso.