VTL Wotan MB-1250 monoblock power amplifier
By Jonathan Scull   •   June, 1998 A lot of electrons have flowed under the bridge since I brought you word of the mighty Vacuum Tube Logic Wotan MB-1250 (originally reviewed in Vol.19 No.10). While I was staggered by the awesome presentation of this $27,500/pair monoblock amplifier, I still found a few nits to pick. I was impressed by Luke Manley's "Manufacturer's Comment" response at the time (footnote 1). Instead of Excoriating the Reviewer, he took my nits seriously and said he'd address them. (Hey, he could be Mr. Magnanimous—it was a rave review!)

Fast forward to fall 1997. It was turning cold in New York City, and my thoughts turned to the clanky, recalcitrant radiators in our old loft building. A flashbulb went off somewhere deep inside my noggin: I recalled rather fondly the 24 Svetlana 6550s per side of the huge, heartwarming Wotans. "Hellooooo, Luke!" And before you could say, "They weigh how much per side?" we were once again with Wotan.

The early-build Wotans shipped with their two-storey chassis separated; some assembly required, as it were. The new units arrived in two massive crates (around 700 lbs!) with the ready-to-run monoblocks tied down within. So there was a grinning Luke Manley, there were these huge crates, but nowhere was there even one Big Beefy Guy to help. Luke, typically unfazed, suggested a quick walk to the hardware store for a furniture dolly. That did the trick—Kathleen, Luke, and I managed to unbolt the amps and schlepp them into place in our listening room.

I noticed right away that the chassis frames were much more rigid than before, and that the entire construct was more solidly built and nonresonant. In fact, the entire front panel—top and bottom chassis—is now fashioned from one huge sheet of aluminum. "Yeah, they can't go rhomboid like that!" exclaimed Luke. I hate when that happens.

The top deck itself is thicker, and the bolts of the output transformer go right through to the bottom cover plate of the top chassis to further enhance structural integrity. The amps are obviously better finished, and sport a beveled edge at the back of the top and bottom chassis for added stiffness and easier access to control functions and cabling. There's also an easy-to-remove tube cage covering the top floor, which I popped off only to bias the tubes. The Wotans now offer both single-ended and balanced inputs, and, as before, switch-selectable triode or tetrode operation. (Remember, ladies and gents, we're talking about 650Wpc in triode and a whopping 1250 big ones per side in tetrode.) The front-panel two-stage turn-on switch is nicely robust, and proved completely trouble-free in operation.

Instead of the previous complement of three power transformers in the power supply, there are now five serving various functions: B+ for the input stage, separate B+ for push'n'pull sides, and separate push'n'pull transformers for the tube filaments. But you can't see them; the entire "bottom-floor" chassis is potted in rubber—very kinky—which keeps mechanical resonance to an absolute minimum. I also learned that the multiple printed circuit boards of the earlier design had been replaced with a single 24" by 24" pcb to prevent flexure. (That's what broke a ground trace and drove us crazy in the first pair we auditioned.) Star-grounding has also been implemented; all grounds have their own trace back to the star-ground point.

I've listened to the new Wotans with TARA Labs The One, Synergistic Research Designers Reference, XLO Signature, and Ensemble MasterFlux cables and interconnect. Preamplifiers included the BAT VK-5i/VK-P10 combo, the YBA Signature 6 Chassis, and the Nagra PL-P. (The Nagra got along famously with the huge monoblocks—I never heard the PL-P sound so sweet, dynamic, and involving.)