Near the end of the review period, with the stock sound of the Signature IIa firmly in my ears, I started rolling linestage tubes. On Hayes’s recommendation, I first tried a pair of Philips E88CC SQ tubes manufactured in Heerlen, Holland. A toggle switch near the right tube socket sets the circuit for one of two types (8416 and 12DJ8; or 6DJ8/ECC88, 6922/E88CC), but since the Philips used the same setting as the stock tubes, I didn’t have to flip it. In fact, all the tubes I tried—pairs of Amperex 7308 PQ, Amperex 6922 PQ, Amperex Bugle Boy 6DJ8, Mullard E88CC, and Mullard E188CC (a 7308)—used the same switch setting. To my ear, the Philips and Mullard E188CC tubes sounded smoother, more liquid, sweeter on top, had more weight, and gave more detailed and longer decays than the stock tubes. The Amperex 6922 and 7308 tubes were more resolving than either, perhaps more balanced through the frequencies, and had superb top-end finesse and air—great for voices. The Bugle Boy 6DJ8s were also airy, but spacious, harmonically rich, and sensuous, especially on orchestral strings. Finally, the Mullard E88CC sounded even more spacious and warm—on the verge of “euphonic,” and, to my ears, mostly pleasing. But these weren’t game-changing differences to me, and I was nearly as content listening to the stock Chinese E88CCs.
Matched with a VAC Phi-200 stereo amp, the Signature IIa consistently produced a clean, punchy, and speedy sound that was never hard-edged. On most orchestral pieces, notably Alfred Brendel’s CD of Mozart’s Piano Concerto No. 12 in A Major, K414 [Philips], strings were sprightly and airy but authoritative when called for. There was an inner liquidity to piano notes. Attack transients were exceedingly fast, just on the pleasing side of sharp, and I experienced no fatigue. Interior shadings—the notes as they developed—were completely natural, evolved in time, and breathy with life. On Brazilian Dreams [Manchester Craftsmen’s Guild] by Paquito d’Rivera with the New York Voices—a CD I’ve used as a demo at shows—I heard, on tune after tune, an amazing clarity, precision, and punchiness without any etch or analytic quality to the male and female voices, brass, and d’Rivera’s agile alto clarinet. I heard more detail and my listening seemed more alert and lit up.
Even with amplified music, the Signature IIa, consistently demonstrated an ample sensuousness as well as excellence with timing, detail, and finesse. Austin’s been the town for live rock for a good couple of decades now and Jimmy Lafave has been one of its local heroes. His live CD Austin Skyline [Bohemia Beat Records] is a treasure. When I spun his cover of 60s hit “Walk Away Renee,” LaFave’s electric rhythm guitar and Larry Wilson’s lead both produced ripe, ringing tones with tasteful plucking and light sustains. Reacting to LaFave’s rough-edged and plaintive veteran wailer’s voice, tinged with smokey shadings, Wilson bent out a clear and bluesy solo, full of aching lamentation. His fills made for open, airy, and privileged interplay with LaFave’s deft frailing and strumming, producing a seamless, sparkling electric tapestry. I noted the drumming had march-like, doublethunks from the kickdrum and that the electric bass was subtle, unobtrusive, and tight. And the organ stayed in the background, too, gently comping and undergirding the whole sonic field until the final choruses, when it emerged and claimed the tune as a dirge. Each of the band’s light crescendos came with a gently rising momentum, making for a succession of sonic swells that captured the ambience and clarity of this live club date.
When I hooked the solid-state Herron M1 monoblocks with their 220k ohm input impedance to the Signature IIa, they were absolutely no sweat to drive. The system sound became warmer, more “tubelike” actually, with more emphasis on the smooth midrange, lovely scaling, and an even more organic flow to the music. Turning to analog, for example, I dug out my stereo LP of Yevgeny Mravinsky conducting the Leningrad Philharmonic Orchestra performing Tchaikovsky’s Symphony No. 6 in B Minor, commonly known as “Pathétique” [DG]. I used a ZYX Airy 3 cartridge (0.24mV) and clicked through the resistive loading options of the mc phono, adjusting the convenient dial on the left of the back panel for ragged violins and tinges of grey in the treble, trying to find the most clear, sensuous, and dynamic sound. On this and other LPs, I seemed to set the load either at 150 ohms or 200 ohms. On Adagio-Allegro non troppo, the first movement, there were gorgeously dark and delicate shadings from the violins at first and big, dark notes from the bass viols. I got a big soundstage, the scaling was impressive, and where came the movement of the theme from the second to first violins, it was a sweet and gentle thing that gave a real sense of spaciousness in the orchestra. Languorous passages with solo oboe fell away to a septet of woodwinds, then pianissimo brass fanfares. Later, there were sudden bursts of orchestral energy, quick turns of pace, and occasional splashes of brass turning to crescendo. The tonal richness of cellos and basses contrasted with the gentler shadings of violins and the piercing sweetness of a clarinet. The abundance of complex orchestral gestures and motifs, the alternately grave and dashing movements of the theme, all showed Tchaikovsky’s orchestral painting at its most tragic and complex, attesting to the Signature IIa phonostage’s sophistication with dynamic range and multiplicities of timbre, showing its breadth of power to communicate Tchaikovsky’s rich flows of momentum and tides of psychological expressivity in orchestration.