Description: Two-channel, tubed stereo (switchable to parallel mono operation) power amplifier. Tube complement: four KT88, three 12AX7A, four 12AT7. Inputs: 1 pair single-ended (RCA), 1 pair balanced (XLR). Loudspeaker outputs: separate gold-plated, 5-way binding posts for 4, 8, and 16 ohms. Preamp output: 1 pair single-ended (RCA). Inputs: 1 pair balanced (XLR), 1 pair single-ended (RCA). Output power: 75Wpc (18.8dBW) into 4, 8, or 16 ohms (stereo), 150W into (21.8dBW) 2, 4, or 8 ohms (mono). Frequency response: 20Hz–20kHz, +0/–0.5dB; 10Hz–70kHz, +0/–3dB.…
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Sidebar 2: Associated Equipment
Analog Source: VPI Classic turntable & JMW Memorial tonearm, Lyra Delos cartridge.
Digital Source: Krell Evolution 505 SACD/CD player.
Phono Preamplifier: Nagra BPS (battery-powered).
Integrated Amplifier: Krell FBI (mainly used as line stage).
Loudspeakers: Revel Ultima Studio2.
Cables: Nirvana interconnects & speaker cables, Nordost CAST interconnect (between Krell components).
Accessories: Bybee Technologies Signature Model Power Purifier (not power amp), Black Diamond Mk.4 Racing Cones, Mapleshade pucks, VPI HW-19 record-cleaning…
Sidebar 3: Measurements
To perform the measurements on the McIntosh MC275, I mostly used Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com); for some tests, I also used my vintage Audio Precision System One Dual Domain. The MC275 has four output terminals for each channel, one labeled "Common," the others "4," "8," and "16." I performed a complete set of measurements from each output transformer tap using the balanced inputs, and repeated some of the tests using the unbalanced input jacks.
With…
Even Mikey Fremer is surprised at vinyl's current popularity. Some pundits postulate that eventually CDs will die out, and we'll be faced with the choice of LPs or downloads. (I hope not. I'm just getting used to CDs.) With abundant sources of new pop releases and a wide range of reissues on vinyl, and a variety of used LPs, every audiophile should own a turntable. And with the availability of affordable turntables such as the Pro-Ject Debut III, which I reviewed in the February 2010 Stereophile, the cost of entry to VinylLand is not very dear. The problem is that so few entry-level…
Finally, with cranked-up rock tunes, the PP 3 exhibited a strong sense of coherence, pacing, and rhythmic consistency, whether reproducing such simple arrangements as Ten Years After's "Love Like a Man," from Greatest Hits (LP, London LC 50008), or more elaborate, densely packed tracks such as Genesis' "Dance on a Volcano," from A Trick of the Tail (LP, ATCO SD-36-129). Listening to either of these tunes, I found it hard to sit still—I itched to twitch, grab a partner, and dance around the room. But my wife wasn't home, and neither of the dogs was interested.
Comparisons
I compared…
Sidebar 1: Specifications
Description: Moving-magnet/moving-coil phono preamplifier with line-level inputs and outputs and an A/D converter feeding audio data to a USB output. Input impedance: 47k ohms + 200pF (MM), 100 ohms + 180pF (MC). Voltage gain: 35dB (MM), 58dB (MC). Input sensitivity at 300mV output: 5mV (MM), 0.38mV (MC). Signal/noise ratio: 76dB, A-weighted (MM); 78dB (MC). Input overload, 20Hz/1kHz/20kHz): 10/100/900mV (MM), 0.65/6.5/60mV (MC). THD: <0.03%, 20Hz–20kHz at 3V output. Digital output (USB): 16-bit linear PCM. Sampling frequency: 48kHz. Dynamic range: 89dB (MM…
Sidebar 2: Associated Equipment
Analog Source: Rega Planar 3 turntable, Syrinx PU-3 tonearm, Clearaudio Virtuoso Wood cartridge.
Digital Source: Creek Destiny CD player.
Integrated Amplifiers: Creek Destiny, Marantz PM5003.
Loudspeakers: Epos M5 & M5i.
Cables: Interconnect: MIT Magnum M3 & MI-350 CVTwin Terminator. Speaker: Acarian Systems Black Orpheus.
Accessories: Various by ASC, Bright Star, Simply Physics, Sound Anchor, VPI.—Robert J. Reina
Sidebar 3: Measurements
I measured the NAD PP 3 with Stereophile's loaner Audio Precision SYS2722 system. (See www.ap.com and "As We See It" in the January 2008 issue.) I examined its performance both from its analog line outputs and in the digital domain, using the Mac version of the free VinylStudio Lite program supplied by NAD to create files from the PP 3's USB output fed to my Apple MacBook. The Mac USB Prober utility identified the NAD as "USB Audio Codec, Burr Brown from TI," and revealed that the A/D converter operates with 16-bit word lengths at sample rates of 32, 44.1, and…
How many of you out there know what a Nuvistor is? Michael Fremer takes a look at this unique device and its application in the Musical Fidelity Nu-Vista 300 power amplifier. "Enclosing its vacuum in metal rather than glass, the Nuvistor was designed as a long-lived, highly linear device with low heat, low microphony, and low noise—all of which it needed to have any hope of competing in the brave new solid-state world emerging when RCA introduced it in the 1960s." Musical Fidelity decided to use the Nuvistor in a limited-run amplifier, and therein lies an interesting tale, which Michael…
Jonathan Scull thinks he has uncoverd the hot audiophile topic for the new millennium—e-commerce. He lays out the situation in "Fine Tunes" #19. Find out what various manufacturers are up to, and why.
Robert Harley was looking for a well-rounded speaker, and thinks he found it in the Thiel CS3.6 loudspeaker. He writes, "the inherent tradeoffs in various designs make it difficult to find a loudspeaker that does everything well. This ideal loudspeaker may not quite reach the pinnacle of performance in individual areas offered by other designs, but its overriding virtue is that it comes…