Ian Grant of Grant Fidelity based in Calgary Alberta Canada kindly lent me two versions of current Chinese manufacture 6SN7 vacuum tubes for a long comparison with the best of my NOS 6SN7 tubes. In effect a long distance shootout between his TJ Full Music 6SN7, Shuguang Treasure (Black Bottle) CV-181Z (actually 6SN7 but labeled CV-181Z) and the best sounding of my NOS tubes Sylvania’s Chrome Dome 6SN7 GTs. I have no commercial or other relationship with Ian Grant or Grant Fidelity. I do, however, own audio equipment purchased from them since my first retail purchase of the A-348 Tube Amp in February 2009. My equipment setup for this test: Cary Audio Design 303/300 Tube CD Player Grand Fidelity A-348 Vacuum Tube Amplifier Klipsch Cornwall Speakers (circa 1979) Grant Fidelity RCA-1 Interconnect Cables Xindak SC-03 Speaker Cables Grant Fidelity PC-1.5 Power Cables G&W Power Filter TW-03D The Cary CDP can be played either in solid state or vacuum tube mode with the touch of a button on the remote. I conducted my listening with both modes but mostly in tube mode for all genres other then Rock and Roll. Tubes used in the CDP throughout this comparison are a pair of NOS British made Brimar 12AU7’s manufactured in the early 1960’s. The Grant Fidelity A-348 Amp uses a quad of KT-88, two 12AX7 and two 6SN7 tubes. Alternatively you can replace the KT-88’s with a quad of EL34B tubes for a smoother sound rendition but less per channel wattage. My A-348 for this test was run using two different configurations during the approximately 500 hours of total testing time. My KT-88 Setup: Shuguang Treasure (Black Bottle) KT-88 tubes Mullard 12AX7 (CV492) NOS tubes And alternatively; Sylvania Chrome Dome 6SN7 GT tubes, TJ Full Music 6SN7 tubes and Shuguang Treasure (Black Bottle, type B) tubes My EL34B Setup: Tungsol (Reflektor) EL34B tubes Mullard 12AX7 (CV492) NOS tubes And again alternatively; Sylvania Chrome Dome 6SN7 GT tubes, TJ Full Music 6SN7 tubes and Shuguang Treasure (Black Bottle, type B) tubes I decided to take Ian Grant up on his offer to “test the TJ Full Music and Shuguang Treasure 6SN7 tubes against your favorite 6SN7 tubes”. This offer was made after I’d spent months tube rolling several different combinations of tubes in my amp and ultimately finding Tube Nirvana with my combination of new KT-88 Shuguang Treasure tubes, NOS Mullard or Telefunken 12AX7 and NOS Sylvania 6SN7 tubes. Ian’s deal was you do the test, compare the tubes and write-up your conclusions on what tubes you find sounding best in your system. One factor in this I’d under estimated was the time commitment required to test 6SN7 tube’s which included the Shuguang Treasure’s and their reportedly 300 hundred hour break-in period. I do a lot of listening to music when working in my home office but to get in over 500 hours between the three sets of 6SN7 tubes it has taken me from early February to now (late April) with an unexpected three week break in between. Sylvania 6SN7 GT Chrome Dome (price paid $100/matched pair) These tubes are well known for their sonic excellence. They produce a warm, lush balanced sound with good highs, full mids and nice full bass. I’ve found these tubes unmatched in comparison to various other NOS Sylvania, Tungsol, RCA and GE tubes made from the golden era of tubes from the end of World War II until the early 1960’s. Nothing else I’ve rolled into my system has compared to these Sylvania’s. As such, I considered them virtually un-beatable and I’ve spent hundreds of hours of listening enjoyment in the last year. TJ Full Music 6SN7 (priced at $200/matched pair – Grade A, $150/pair – Grade B) I ran these tubes for a total of 200 hundred hours to get them fully broken-in per Ian. They sounded somewhat brittle and bright for the first 10 hours and didn’t really start to open up significantly until 50 hours in when they started to smooth out and compete with my better Sylvania and Tungsol NOS tubes. Better sounding again at 100 hours where they seemed to plateau with no discernable sound differences between the 100 hour mark and the 200 hour point where I completed listening. At 200 hours I consider them an excellent sounding tube and a close match to the NOS Sylvania’s. Very comparable sounding to Tungsol 6SN7 Mouse Ear tubes which also exhibited similar sound characteristics. They are detailed with a smooth but slightly less warm sound then the Sylvanias. Bass is not as full but they are dead quiet in my amp and can be purchased with a full 12 month (extended) warranty from Ian. Shuguang Treasure (Black Bottle) CV181-Z/6SN7 (priced at $320/matched pair –Grade A, $275/pair – Grade B) Ian was out of stock of his Grade A matched pair tubes so I borrowed a pair of his Grade B tubes. They were reasonably closely matched on his Amplitrex AT1000 tube tester but were not with-in the 5% tolerance he considers matched and therefore Grade A. Shuguang has pulled out all the stops here with the look of these tubes, they are big, black and beautiful! At twice the size of any NOS 6SN7 tubes I’ve seen the tube cage on my amp will not fit on with these tubes installed. This is of no concern to me but this may be an issue wrt WAF. They certainly got the fish eye from two out of the three women around here. How did they sound? Well for the first ten hours they spit, crackled, and seemed generally unhappy in my amp. Shortly over ten hours the spitting and crackling disappeared to be replaced with a nice balanced sound stage with nice highs, detailed bass and mids. At this point they were better sounding then any NOS tube I had rolled into my amp in the previous year other then the Sylvania’s and Tungsol’s discussed above. At 50 hours they were better sounding then the TJ Full Music 6SN7’s were at 200 hours. By 100 hundred hours I knew I had a special sounding tube as they were better then my favorite Sylvania tubes. Just beyond 200 hours of listening time they were unsurpassed! At one point my tinned eared housemate stopped in her tracks to comment that Jack Teagarden sounded like he was singing Beale Street Blues with the band playing along in the room. She was right! Teagarden, Armstrong and my entire collection of Jazz had never sounded better. Louis Armstrong, Holly, Natalie and Nat King Cole, Charlie Parker, Stevie Ray Vaughan, Rod Stewart, Marvin Gaye, Eric Clapton, Pink Floyd, CCR, the Beatles and everything else including my classical CD collection has never sounded better. It didn’t matter whether I was using the Black Treasure KT-88’s or Tungsol EL34B tubes for power tubes the music just sounded great! I ultimately ended up preferring the KT-88’s for Rock and Roll, Motown and Pop and the El34B’s for my Blues, Jazz and Classical albums. Conclusion Shuguang has raised the standard with their Black Treasure series tubes with the KT-88’s and the CV181-Z/6SN7 providing better then the best NOS sound in a modern manufacture tube. The bottom line: IMO these tubes are big, bad and expensive but well worth the price premium for those seeking the best sounding tubes!