To me, the older Lambdas had a different balance than the 404s which I own now. The 404 has better bass and is less bright than the original Lambda, as I recall. That said, I think some of the older Stax phones sound great. I have a set of the "New SR-3" phones (really old model!) that I think sound great, though not as detailed or as extended in the bass as the 404s. I run them both off the Stax 006t tube amp. Whichever Stax phones you end up with, I don't think you can go too far wrong.