I have a Line6 Toneport UX2 and a Behringer Xenyx 1622FX, and I've been thinking about adding a hardware preamp like a Grace Design Model 101 or a Universal Audio Solo/610/110, or even a channel strip like a PreSonus Eureka or dbx 376. I'm wondering if I'll get big improvements, or I should continue to tweak the vocal preamp models in Toneport's Gearbox to get better sound. Right now I feel that the preamps I have on the audio interface and mixer are decent, but they don't have any real headroom, especially for a mic like the SM7A, where I'd have to crank the preamps all the way up for decent volume. (My other mic is the AT-4033, which being a LDC, is comparatively easy to drive.) I record vocals (all kinds), acoustic and electric guitars, electric basses, synths, and pretty much anything else that can fit into my project studio. I also compose a wide range of styles and genres--pretty much anything you can think of. So, can anyone compare the preamps on audio interfaces/low-end mixers to the hardware preamps I mentioned? Will the cost justify the improvement, or are we talking about diminishing returns here? Another angle is that I can tweak the recordings ITB with plugins--EQ, compression, analog warming emulation (PSP Warmer), and if that is enough to get me great results, I'm fine with it. But since I've never used a dedicated preamp/DI box, I don't really know if I'm missing out on anything.