Audio Research ls 15/16 Tube rolling

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

I liked the Ediswan's in my LS15 the best.

Kehut,fine post.I have a Great Northern Sound modded SP-15,with infinicaps/Elna and Black Gates in various circuits,within.I have and love my Ediswans(3 tubes in phonostage),however just went for my "LUNGS" on a set of ULTRA LOW NOISE Siemens CCa's(early 60's).These are going in this weekend.I do hope I like them "alot" better than the Ediswans,or I'll shoot myself,based on what my expectations are,and what I payed.I have absolutely no complaints with the Ediswans,which are of a very high pedigree as regards to how they tested(very low noise,too),but have heard so much about the Siemens,especially the vintage I just got,that I had to see for myself.BTW,my pal has the exact Pre as me,and an almost identical system,he has the Amperex PQ 6922's,which sound quite similar to the Ediswans.Best of luck.Especially to me on Saturday!!

Sirspeedy...Very good. The CCa of early vintage offer a very smooth, yet textured sound. Very palpable compared to the later CCa's and other Siemens tubes IMO. The highs should be more smooth but maybe less transparent than the Edi's. The bass will be more robust on the CCa's...but perhaps not as tightly defined as the Edi's..you'll have to hear for yourself for sure. You can always resell either tube after you give it some time to evaluate them.

OLcm--I forgot to make mention of my new favorite 6922 Im using in my ARC PH3SE phono pre amp. I replaced my early CCa's with a trio of Russian(yes...you read correctly!) 6H23n-eb SLNM Cryo's tubes available from Ken( no relation either personally or professionally) at ATSI in Florida. This tube is killer in every way and has to my ears all the sonics we want in a tube. Linear, yet warm. Detailed and resolving..yet not at all bright or grainy. Excellent bass without bloat or tubbyness and miles of depth and soundstage abilities that embarras many NOS tubes....Bottom line...If I were lookoing to retube my LS15 now..I would definately give these tubes a whirl. A matched pair is about $75.00 and well worth the cost for a quad....Ken