I have the LS-15 and recently got some Siemens 6922s and some Sovtek 6922 old stock tubes as, I hope, an upgrade. You can contact Upscale Audio (website is upscaleaudio.com) or thetubestore.com for recommendations and purchases. Also, there is currently an auction of some good 6922s on Audiogon, I think they are Siemens too. How do you like your preamp?
