You have a really good preamp. If you are simply looking to make a change to hear tubes with your SFs, I would consider trying the Music Reference RM10MKII, which sound great, is extremely reliable, and uses the wonderful EL84 tube. It gives you 35 watts per channel, don't know if that is enought for your speakers - not sure. All for $1,995 new!. Occasionally they might come up used for $1,200 or so, but you don't see them up for sale that much. Oh, and they get 10,000 of power tube life to boot. Now, if you are looking for an integrated for some reason, that is another issue. I do think the Stingray is one of the better sounding units out there, but there are other options.