Tubes Asylum: REVIEW: Balanced Audio Technology (BAT) Preamplifier (Tube) VK-50SE by Rod M

Originally Posted by Rod M on April 01, 1999 at 09:39:12:

Last night, the San Diego Audiophile club had their monthly meeting at Stereo Unlimited's new shop. In addition to drinks and finger food, the main course for the evening was Balanced Audio Technology's Director of Sales, Geoffrey Poor (one of the 3 founders of BAT). I had hoped to also meet Rafe and did see him at the meeting, but unfortunately, we crossed e-mails and didn't get a chance to actually meet. So here goes:

The topic of the evening was BAT's new VK-50 SE pre-amp and it's new secret Russian tube, the 6H30. Before we get to the meat here, a little background. BAT has replaced the old 3i/5i with a VK-30 and VK-50. The new 30 is characterized as being this close (Geoffrey is holding his thumb and index finger about an inch apart) to the old 5i. In effect, the new 30 is purported to be a 5i with the exception of a shared power supply. The solid state VK-40 is in BAT's opinion, comparable to the VK-50 and maybe a touch
better in some aspects as well as being an alternative to those that don't want to mess with tubes. The flagship VK-50 is a 6922 based pre-amp and the SE (Special Edition) model is the only one using the secret Russian tube.

Now this was a nasty group of tube loving hecklers. And BAT's hype fits right in: zero negative feedback, no followers, no buffers, fully balanced, yada, yada. Mr. Poor was an excellent presenter and a real music lover. He also exhibited a fine sense of humor and was well versed in dealing with a nasty group. In warming up the crowd, Mr. Poor discussed the virtues of their designs and at one point asked, "What does twelve 6922s in the circuit mean to you?"

Hmmmm, being a heckler myself, I answered, "That it will cost a fortune to retube with Bugleboys!" Wrong answer, but the laughter from the crowd told me this was going to be fun. Well, the correct answer is that you get double the current and half the impedance. I haven't a clue what that really means but it's why BAT uses so many tubes in their designs.

OK, on to the main course, the VK-50 SE is a limited edition model of the VK-50. It retails for $7,000 plus $500 for remote. VK-50s can be upgraded at a $500 penalty. The SE gets 2 special torodial power supplies plus double the capacitors for 400 joules of energy storage. It also gets 8 of the new 6H30 tubes.

Surely most know that Victor, the head designer at BAT, is a Russian and well connected with the old Russian scientific community. The 6H30 was designed for the Russian military. It's a 15 year old tube that is
somewhat based on the 6922 but was designed for more gain and lower noise I believe, possibly for radar applications. It is not in current production.

Enter back row heckler, "If it's out of production and hasn't been made for 15 years, how are you going to support the owners for tube replacements?" Hmmmmm, well BAT bought the entire World supply of these tubes, all 11,000.

Now BAT is hot on this tube. They believe that it simply excels at dynamics, low noise and all that good stuff. They have an exclusive now and claim that the production line can be restarted if it becomes as popular as they believe it will be. There were also innuendoes made to the effect that another unnamed tube guru/manufacturer (Ricardo was mentioned, who's that?) is also most interested in this tube and may have the clout to knock BAT's exclusive out of the water and get the production line going again.

Of course, Mr Heckler didn't buy that one. "How can you guarantee that the new tubes will sound like the old ones? It's not the same people making them. Procedures and specs just aren't well documented. I don't buy it." Neither did most of the crowd. Poor, Mr. Poor, he danced, he wiggled, he finally got the subject changed.

Ok, let's assume there is no new production. BAT claims that they intend to sell only 200 units of the VK-50 SE. The balance of the remaining stock of tubes will be reserved to support the owners for retubing. What's it cost? Try $100 per tube or $800 for a new set of 8. A squirming Mr. Poor, let's talk about something else. Want to hear it?

The VK-50 SE was paired with the VK-D5 CDP, VK-60 tube amp and Dunlavy IVa speakers. The room was 16X26 with 10 foot ceilings. Floor to ceiling treatments were placed in the corners of the front wall with minimal treatments on the back wall top corners. An interesting square box treatment was placed in the center of the ceiling made of 4 18"x24" panels making a box and positioned opposite the room with the points toward the flat walls. Speakers were placed on the short wall about 5 feet into the room and 4 feet from the side walls about 8 feet apart and toed in about 25 degrees. The sound was exceptional.

First we had to do the feature tour. Five balanced inputs, each one can be set up with a bunch of presets. The display is a pleasing blue. You can program your own name for each input. In addition, each input can have it's own preset balance, max volume, volume differential (to match input levels when you change sources), phase, pre-set volume (for HT integration), stereo/mono and maybe a couple more. Adjustments are in 0.5 db increments. These features are common to all the new BAT pre-amps I believe.

First up was a jazzy, blues recording featuring a trumpet player. Each breath and the delicacy of his lips and breath on the mouth piece was clearly conveyed without a hint of sibilance and in a very natural manner. An excellent test of microdynamics and this system excelled at nuance. A selection from James Taylor's Unplugged was equally impressive and put James not only in the room but up on stage, attack, transients, tonal balance, it had it all.

All in all, a World class system enjoyed with a wonderful crowd of tube lunatics and an excellent presentation from Mr. Poor.

REVIEW: Balanced Audio Technology (BAT) Preamplifier (Tube) VK-50SE Review by Rod M at Audio Asylum