My $0.02 worth - they don't have a consistent house sound, but rather have models that cater to different taste. Some can be quite bright, while some can be full and rich.
I only have experience with their ICs and power cords. But the Tunami Terzo or the AR / AZ 910 are detailed yet super duper smooth and grainless. Warm and rich power cord ? That would be the Tunami GPX-R V2.