Tube rolling the C2300 is crucial, in my experience. To me the stock tubes are a bit harsh and noisy. Most users swear by Telefunkens but I find them, while balanced and extended, a little too polite. Mid-1950s RCA Long Black Plate 12AX7 with D-getters add body and bass while keeping plenty of sparkle on top and excellent midrange. They're readily available and not too pricey. Great tubes. My personal favorites are Medical Grade Holland Amperex, which are incredibly focused and dynamic but might be too bright for you. And they're very pricey. Current issue Mullard 12AX7 (made by New Sensor in Russia) have a classic warm, fat tone and are very cheap. But of course, you'd have to take the leap of faith on the components before tube rolling and I'd certainly understand why you might not. Good luck!