I currently use a Carvin R600 with a SWR Goliath 4x10 bottom. I bought the amp after trying out an Eden amp of similar power (but much higher cost) together with an Eden 4x10 cabinet. I noticed a distinct warmness and sweetness in the Eden, which does not appear to be present in the Carvin. What in amps causes the differences in sound. Is it wattage, head room, parts? Further, what amps out there are known for their super warm sound?