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Phono stage
As mentioned earlier, the Pre-2 is equipped for both MM and MC cartridges. The factory setting was MM so I tried my Rega Planar 3 with RB300 arm and Elys cartridge. The low resistance and inductance of the cartridge seemed to work in perfect harmony with the Texas NE5532P based phono stage. With the simple-is-best low inertia high compliance tone arm, music reproduction was in control. I don't know how much interface was between the phono opamp and the 6SL7 tubes as somehow valve bloom was less obvious than, guess what ... from a digital source. A comparison between the vinyl pressing and polycarbonate molding of the same recording of Rossini's Sonatas for Strings lead by Accardo [Philips LP 4769648 versus Philips CD PHCP-20357/8] proved this point.

Each attack/sustain/decay protocol was executed in a swift, non-lingering manner yet the sound was never dry, just cleaner. Depending on the recordings and from most of the vinyl I spun -- like my all-time favorite Villa-Lobos' Uirapuru [DCC LPZ1003] conducted by Stokowski, a remastering of the legendary 1958 recording [Everest 3016] -- reverberations remained realistic and the resonance of the orchestral hall could be rich and convincing. A very reasonable performance considering this was a basic IC affair. Microphony or ringing were non-existent. As was rumble. But I did try the remote-controllable rumble cut anyway just to check. It didn't add or take away anything. As a subsonic filter circuit, it'd only be audible if rumble were detected from the platter or picked up from the groove.

I was expecting even better results with my Denon DP-57L turntable and DL-302 MC cartridge. Setting the dip switches through the two holes on the bottom plate was easy - flip and dip. But I was mildly disappointed. I had to dial up the volume to get enough level and hum became audible. The 0.25mV output of the DL-302 was too low for the input sensitivity of the preamp at 0.3 to 1mV. Just to check, I re-routed the Denon output through my Ensemble PhonoMaster phono stage to the Aux input of the Pre-2. The Ensemble's 0.15mV sensitivity saved the day and immediately regained sound pressure to my comfort level. Users of the Pre-2 who intend to use MC cartridges should pay attention to sensitivity matching to avoid issues. At this point it's fair to conclude that the phono stage of the Pre-2 is mostly a token feature that will come in handy for some whereas real vinyl hobbyists won't take it too serious. They would have opted for a real phono stage anyway.


Bi-wire inputs
No, you didn't misread that - a bi-wire amplifier input. Each Nova M-34 monoblock features a pair of RCA non-balanced inputs for this uncommon purpose. The idea is for you to mix and match two of your favorite interconnects, say one that excels at low bass and the other at a more silky sheen in the treble. Too bad the Pre-2 has only one set of outputs so Y-splitters to the rescue. I tried bi-wiring with various gold-plated pure copper cables, mixed with Luscombe LBR-35 pure solid silver non-shielded interconnects. Once I started, I couldn't stop. It wasn't just fun but addictive. Yet after a few days, I couldn't tell which was which. The only thing I could honestly say is that the Nova M-34s sounded beautiful in single-wire or bi-wire, copper or silver. As far as interconnects are concerned, these amps are marvelously versatile and accommodating. At this stage, I'm totally absorbed by their musicality. It's shameful for a reviewer to admit but I do have the nerve to say that I am now too lazy to do the plugging and unplugging and jotting down all the A/B findings. The amps occupy my mind with music making more than cable matching. I have no intention to drag us into trivia nor the energy to open a "bi-wire recommendations" sidebar. So allow me to conclude on this subject as follows: To a believer, it's endless fun. I actually pulled one wire out to see what would go missing. To a non-believer, call it psychological wellbeing - and who can fault an audiophile for that? But here's one final tip: If you are hooking up only one interconnect, use the socket closer to the corner. That's the shorter signal path.

Triode/Ultralinear + NFB
As mentioned, many of the Audio Space power amps and integrateds sport triode/ultralinear selection and negative feedback adjustments. These are two seemingly unrelated features but in actual application, I find them intricately linked. First, what's the fuss about triode and ultralinear? Basically, KT88, EL34, 6L6 and other beam tetrode (and penthode) tubes are fitted with two screen grids that give the option to be configured as a common cathode amplifier in various ways. Tetrode mode is the normal connection with the screen grid connected to a regulated DC voltage. But who would do that? There's no fun. Triode mode is having the screen grid connected to the plate, in a way converting the tetrode into a triode. Ultralinear mode is a combination of the above by adjusting the percentage of the output signal from the plate impressed onto the first screen grid and connecting the second screen grid to the output transformer's higher voltage tap from the primary winding, yielding a higher output power. The crucial job for the amplifier designer is to determine the relative percentages of plate output and primary winding. It is this judicious choice which makes one such amp different from another.

What exactly do we gain with ultralinear? To begin with, ultralinear is definitely technically superior to the original tetrode (or penthode): lower impedance (yet still twice that of triode), lower distortion that approaches triode and power output that approaches a full power tetrode. The output power of ultralinear is roughly double that of triode so it appears to be more dynamic. In reality, at the same output sound level pressure, triode actually has better drive and dynamic response. The real advantage of ultralinear is its capability to tolerate extreme dynamic range without clipping (saturation) and to depict a wider, clearer soundstage with detailed instrumental placement of orchestral complexity. Triode, on the other hand, has better control due to its lower internal impedance which increases damping factor. In a normal listening room, say about 300 square feet, triode offers more than adequate dynamic range. The soundstage might not be as wide but is more focused, with more textural details and three-dimensional imaging.