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Nirvana Audio's cables have long been fixtures in my audio system: first the SL interconnects and speaker cables, and, after their debut in 1998, the S-X Ltd. interconnect. In 2002, after a long development process, designer Stephen Creamer introduced the companion S-X Ltd. speaker cable ($2780/2.5m pair, add $50/pair for biwire configuration). He explored a wide range of options, including dramatically different structures and materials, but always returned to the elements he'd used before—and ended up with a design that combined elements of his two existing speaker cables, the SL and the…
Sidebar 1: Specifications
Description: Single or biwired loudspeaker cable.
Price: $2780/2.5m pair, add $50/pair for biwire configuration. Approximate number of dealers: 18. Warranty: limited, lifetime, transferable.
Manufacturer: Nirvana Audio, P.O. Box 448, Lynbrook, NY 11563. Tel: (516) 593-4700. Fax: (516) 593-1997. Web: www.nirvanaaudio.com.
Sidebar 2: Associated Components
Analog Source: VPI HR-X turntable & tonearm, Lyra Titan cartridge.
Digital Source: Burmester 001 CD player.
Preamplification: Ensemble Fonobrio phono, Sutherland PhD phono stages; Placette Remote Volume Control; VTL TL-7.5, Burmester 011 preamplifiers.
Power Amplifiers: Simaudio Moon Rock, VTL S-400.
Loudspeakers: Thiel CS6.
Cables: Interconnect: Nordost Valhalla, Audience Au24, Silversmith Silver, Nirvana S-X Ltd. Speaker: Nirvana SL. AC: Audience PowerChord, Synergistic Research Designers' Reference.
Accessories: Finite Elemente…
Just who does Bruce Rozenblit think he is? And why is he saying those things about the late Julius Futterman? Rozenblit, relying heavily for guidance on his Electrical Engineering degree, has crafted an OTL (output-transformerless) amplifier that flies in the face of contemporary design dogma. To hear Bruce tell it, he's tamed the breed—this is how OTLs should have been done to start with, Futterman notwithstanding.
Ah yes, Futterman; the looming father-figure of contemporary OTL designs. Most audiophiles have heard of Father Futterman's amplifiers and their reputation for…
Sidebar 1: Futterman Redux
We come now to the pièce de résistance of the Transcendent T8 design. Mr. Rozenblit is justifiably proud of US Patent #5,604,461, which he received on all 20 points of his application. (The last OTL patent awarded was to Julius Futterman back in 1964!)
Here's the gospel according to Rozenblit. With Futterman-style driver circuitry, the overall forward voltage gain through the amplifier is unequal due to the "parasitic" or "degenerative" effects of negative feedback. Futterman took the output signal and coupled it to a phase splitter to compensate for…
Sidebar 2: Who does Bruce Rozenblit think he is?
Jonathan Scull: The question I want to ask is, Just who do you think you are?
Bruce Rozenblit: [laughs]
Scull: Just kidding. But really, here you are claiming to have fixed all the problems in Futterman's OTL design.
Rozenblit: Yes, exactly.
Scull: Well, that takes balls...
Rozenblit: Yes.
Scull: What defining moment launched your audio building career?
Rozenblit: Well, years ago I picked up a little EICO tube amp, their version of the Dynaco Stereo 70. I'd never even heard tubes…
Sidebar 3: System
The Transcendent T8 OTLs were dropped into essentially the same system as that used in the Graaf GM 200 OTL review. The Joseph Audio RM-50s sounded best set up on a combo of Shun Mook Diamond Resonators left'n'right rear, with a single AudioPoint up front. We placed Harmonix RF-56 Tuning Bases on their sides—at woofer level—to excellent effect, and tweaked the soundstage with a trio of Mpingos Discs on top. I made extensive use of both Shun Mook and Harmonix footers throughout the system.
Digital front-ends included the suave Ensemble Dichronos, the ever-bloomin…
Sidebar 4: Specifications
Description: Output-transformerless monoblock power amplifier. Tube complement: one 12AX7, two 12AU7, eight EL-509. Power output: 80W into 8 ohms (19dBW), 50W into 4 ohms (14dBW). Signal/Noise Ratio: >90dB. THD: <0.5%. Frequency Range: 5Hz–50kHz. Waste heat: 274W at idle. Design protected by US Patent No. 5,604,461.
Dimensions: 17.5" W by 9" H by 18.5" D. Weight: 40 lbs.
Serial numbers of units reviewed: none found.
Price: $6995/pair (1997); no longer available (2006). Approximate number of dealers: 8. Warranty: 2 years parts and labor, 6 months…
Sidebar 5: Measurements
Because of the high-power limitations of the Transcendent OTL monoblock's tubes, its manufacturer recommended against a high-power pretest. Instead, I warmed up the amplifier at 1W for one hour, following which I tweaked the bias in accordance with the directions in the owner's manual. The amplifier runs quite warm, but not unexpectedly so for a tube amplifier.
The Transcendent's input impedance measured 115k ohms, its voltage gain a very low 20dB. I strongly recommend that if your loudspeakers are of average sensitivity, you pair this amplifier with a…
Nagra's VPA amplification system consists of two slim, handsome monoblock amplifiers intended for vertical placement. They look good adjacent to the speakers. However, two 845 tubes put out a lot of heat, so the amplifier should be at least a foot away from your speakers...unless you're looking for a nice crackle finish.
The chunky 845s sit bravely atop the casework, one in front of the other, and therein lies a brief tale. A pair of "mandatory optional" tube protectors is now supplied with every VPA. These can be returned through the dealer for a $1200 rebate, provided you sign a…