The Lounge LCR has a huge bass hump in its response. It’s an incredibly inaccurate RIAA curve, so probably not fair to expect any other preamp to offer similar levels of midbass. The Lounge is a good example of why these days, I am weary of purchasing products from these small outfits basically operating out of a garage. I’ve had enough experience with such companies regarding product quality and performance to conclude that one is often better off buying from the big brands with established distribution and polished manufacturing processes.
Anyhow, your ears will eventually adjust to the new sound and no doubt you’ll conclude the 20/20 is a worthy upgrade.