I have a line on a Heathkit AP-1800 preamp. It's being sold AS-IS for $200, so I'm leery as I can't test it at this store. I kinda want to know if it's got 'audiophile sound' or if I should just pass on it. I have lots of preamps I like: Carver C-16, C-6, C-1, C11, Phase Linear 2000, 3000...