Hi Walt. Well, one is an integrated amp with a MOSFET power amp and the other is a phono amp with a source selector and output buffer. But you know that. The 25R preamp will sound a little better in every area using the stock tubes in both. However, the Croft responds very well to tube rolling. A set of Telefunkens in the Integrated could sound better than the stock preamp. The better the ancillary equipment, the better the 25R will perform. Not sure if that answers your question. I have the 25R with top-notch tubes. I’ve seen it through some DIY upgrades that have doubled its sonic quality. I also have the 25 phono and the RS RIAA.