Ive rolled a few in my old LS15. Tubes definately change the sonic character of the pre amp as well as a good power cord upgrade(if you have the later model IEC type)
If you want lush try the Amperex Bugel Boys, Mullard 6922 or Amperex PQ(holland or US) USN are a bit more linear but very nice, and any of the Holland Herleen plant tubes are good sounding as well. The BB's give up a bit of resolution and bass, but are sweet in the mids.
If you want supremely transparent try the Tungsram Red print 6922 HM(Hungarian Military) tubes.. avoid the yellow print type also...the Ediswan 6DJ8 is a super nice tube in the 15.The Tungsrams are killer at depth of soundstage, transparent mids and deep bass..a real sleeper of a tube! But some find they miss the warmth over time. The Edi's do it all and are really dynamic and quiet for a 6DJ8..but are hard to find tubes.
If you want a neutral and very linear sound, try the Siemens 6922/ 7308 in the late 70-80's vintage, The early type 60's are smoother and have better bass, but somewhat more closed in sounding in comparison...its a matter of taste with these. I liked the Siemens family of tubes in the ARC overall to my taste, but again it will be a matter of preference. You'll probably have to try various types and makes before finally choosing which one sounds best to your ears. I didn't try any of the Telefunkins in the 15.
The 15 is a nice sounding pre amp especially with the Infini caps and a better PC on it. Good luck!-Ken
If you want lush try the Amperex Bugel Boys, Mullard 6922 or Amperex PQ(holland or US) USN are a bit more linear but very nice, and any of the Holland Herleen plant tubes are good sounding as well. The BB's give up a bit of resolution and bass, but are sweet in the mids.
If you want supremely transparent try the Tungsram Red print 6922 HM(Hungarian Military) tubes.. avoid the yellow print type also...the Ediswan 6DJ8 is a super nice tube in the 15.The Tungsrams are killer at depth of soundstage, transparent mids and deep bass..a real sleeper of a tube! But some find they miss the warmth over time. The Edi's do it all and are really dynamic and quiet for a 6DJ8..but are hard to find tubes.
If you want a neutral and very linear sound, try the Siemens 6922/ 7308 in the late 70-80's vintage, The early type 60's are smoother and have better bass, but somewhat more closed in sounding in comparison...its a matter of taste with these. I liked the Siemens family of tubes in the ARC overall to my taste, but again it will be a matter of preference. You'll probably have to try various types and makes before finally choosing which one sounds best to your ears. I didn't try any of the Telefunkins in the 15.
The 15 is a nice sounding pre amp especially with the Infini caps and a better PC on it. Good luck!-Ken