Reviews

TJ Music Full Music Vacuum Tubes Treasure From China

By Jeff Dorgay

tj_1

If you love tubes as much as I do, you know the lure of finding great NOS tubes.  There aren’t that many lurking in garage sales anymore, so the chance of finding a cache of Mullards or Telefunkens for five bucks is slim to non-existent.  Even the old ham radio operators know about eBay now and price their booty accordingly.

The designer and end user face the same dilemma; where to get the good tubes without breaking the bank.  Many love the sound of the old Telefunkens, Mullards and Phillips 12AX7s, but the best examples can fetch 200 – 300 dollars on the right day.  Just like buying parts to restore a vintage Porsche 356, there are only so many NOS parts to go around and those remaining get more expensive by the day.  Fortunately all but the very best 12AU7′s are still below 100 dollars each, but again as supply goes down and demand goes up, the end result is inevitable.

New New Stock

Having had excellent luck in the past with the TJ Music 300B’s, I was anxious to try their small signal tubes and was pleased with the results.   The folks at Grant Fidelity are now the North American importers for these tubes and you can see their full selection at www.grantfidelity.com  These are brand new tubes, manufactured in Tianjin City, China.

Both the 12AX7 and 12AU7′s are 55 dollars each and for an extra 10 dollars per tube you can get the standard 30-day warranty extended to 12 months.  If you listen to your system fairly frequently, I suggest spending the extra 10 dollars, as tubes will usually fail around 1000 hours if they do not exhibit immediate defects.

First test: Phono

The low noise requirements of a moving coil phono preamplifier seemed like the best place to start with the TJ’s, if they could pass this test, I figured they would probably ace serving as driver tubes.  Unfortunately, my Nagra VPS phono stage uses a 12AX7 and a 12AT7, so I’m going to keep my fingers crossed that TJ comes out with a 12AT7 (and a 6922) soon.

The Nagra VPS is a rare component that does not respond well to tube rolling.  I’ve yet to use a vintage NOS tube that has done a better job than the standard, handpicked EH tubes that Nagra chose for duty in this preamplifier.  Swapping the EH 12AX7 for a very expensive Telefunken just muddied up the midrange and switching to a Mullard slowed down the presentation and increased background noise.

The TJ was a much different story, this tube showed an improvement across the board.  Dynamics were increased, with extension at both ends of the frequency scale, without any harshness.  I dragged out a few favorite warhorses that I’ve heard quite a few times to make the judgment as easy as possible. Right from the first record, Dire Straits Communique, I was impressed.  My copy of this is just an average pressing that you can purchase in any used record store for about $5 and is somewhat compressed.  Just swapping in the TJ 12AX7 gave this record much more impact and I was hearing some low level detail throughout the record that I had to strain to hear before.  Moving on to the second Chicago album (the current Rhino remaster) had the same result.  When using the stock 12AX7, the horns in “25 or 6 to 4″ seemed to be on the same plane as my MartinLogan CLX’s, but with the TJ 12AX7, the horns jumped out of the speaker plane and were right in front of me, with the image having much more front to back dimensionality.

tj_2Second test:  Driver

The next step was to pop a pair of TJ 12AX7′s and 12AU7′s in one of my Prima Luna Dialogue 7 monoblocks while leaving the other one as it came from the factory.  This time switching to the Harbeth Monitor 40.1′s, I played a handful of Classic Records recent mono jazz releases and switched back and forth between the left and right channels, both receiving the same mono signal, leaving no doubt to the change.

In case you are not familiar with the Prima Luna amplifiers, they are somewhat on the warm, lush side of the tonality scale, which is more often than not a good thing.  You can get a slightly more modern tube amplifier sound by swapping the KT88′s for some NOS Tung Sol’s or similar, but those tubes are fetching upwards of 250 dollars each these days.  That shakes out to almost half the original purchase price!

Fortunately, you can get very close to the same effect with the TJ’s.  If you like the more vintage sound of the Prima Lunas, stick with the stock tubes, but if you would like more punch, this is a great investment that won’t break the bank.

TJ’s for me!

The only thing that can’t be verified at this time is how long these tubes will last.  My experience with current stock Russian and Chinese tubes has shown a lifespan of about 3000-4000 hours with a failure rate of about 25%, so this will remain a question mark for now.  I’ve been running the 12AX7 in my Nagra VPS, which sees about 12 hours a day duty and my trusty Radio Shack stop watch is up to about 1400 hours with no problems so far.  I’ll be sure to report back in about a year, when I’ve run the clock beyond the 5000-hour range.

For now, the TJ’s are highly recommended if the tonal changes I’ve mentioned sound like a plus to you.  I’ve always had great luck with the folks at Grant Fidelity, so you can shop with confidence.

http://www.grantfidelity.com