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The Boulder 1012's is a line-level preamplifier and DAC in one box. Its design and build qualities are icons to elegant engineering know-how. No screws show on the rectangular box of large but not massive proportions, for example, which is all done up in matte aluminum and set off with a few highly polished stainless-steel buttons. The chassis construction uses tongue-and-groove techniques. The sides of the 1012 benefit from styling cues found on Boulder's newer amplifiers. As you can see from the photograph, the look is both elegant and hi-tech in a way very few other manufacturers manage…
The 1012's inputs are fully programmable; my unit displayed "Krell" for analog input 1. A subliminal message? No, van Allen sighed, just the remainder of a demo he'd done earlier with Krell gear. But the user interfaces (naming inputs, adjusting gain and phase for each input, etc.) on many newer components are really well-thought-out, making settings more accessible—fun for the whole family! (The best of the user interfaces is still BAT's, I think, closely followed by Mark Levinson's.)
Like many components with audiophile pretensions, the Boulder 1012 features fully regulated and…
Sound
I first listened to the 1012's DAC directly using a Wadia 270 CD transport—which has, perfectly, an AES/EBU output. Yes, the two sections that make up the Boulder 1012 did have a sound, and one that's not very difficult to describe. It's all about the good side of descriptors like "clarity," "transparency," "speed," "fast" leading-edge transients launched with staggering detail—every nook and cranny—especially when running through the already Lotus-like built-for-speed Linn Klimax Solo 500s.
I first listened to the 1012's DAC directly using a Wadia 270 CD transport—which has, perfectly, an AES/EBU output. Yes, the two sections that make up the Boulder 1012 did have a sound, and one that's not very difficult to describe. It's all about the good side of descriptors like "clarity," "transparency," "speed," "fast" leading-edge transients launched with staggering detail—every nook and cranny—especially when running through the already Lotus-like built-for-speed Linn Klimax Solo 500s.
Another sonic advantage of this type of processing is the way the acoustic tails off…
All these acoustic elements sounded quite different on the Boulder's digital inputs direct from the Wadia 270 transport. Yes, the sound was incredibly transparent and made me jump with dynamics. But it lost something of the velvety quality in the mids, even with the Krells. Nevertheless, the sound was big, huge, wide, attractive, and deep as the blue lagoon. Going direct in digitally, I lost something of that midrange magic I'd heard through the analog inputs fed by the dCS and, to a lesser degree, from the Linn CD12. Male vocals, like Lou Reed and John Cale's Songs for Drella (Sire 26140-2…
Changing to the 16/44.1 version of the same recording through the Wadia transport direct into another of the digital inputs, I found the sound slightly less relaxing but more dynamic and swingin'. It sounded good, too, but more sharpish—like the polygons, squares, and circles that graphics softwares use to create an image. The high-resolution recordings from Classic and Chesky sounded more of a piece; more put together and finalized, so to speak, and embodying that special ease I crave and associate with SACD.
I also tried feeding the 1012 with upsampled 16-bit/44.1kHz recordings…
Sidebar 1: Specifications
Description: Line-level preamplifier with integral D/A converter. Digital inputs: 3 AES/EBU, convertible to S/PDIF with DABL adapter (included); 1 TosLink. Sampling rates: 32, 44.1, 48, 88.2, 96kHz. Digital signal-processor speed: 1 GFLOP, 167MHz clock. Decoding system: 64-bit math, 24-bit output. Upandoversampling ratio: 16x (32, 44.1, 48kHz sample rates), 8x (88.2, 96kHz). Analog anti-imaging filter: 3-stage, 6-pole Bessel. Analog inputs: 3. Phono inputs: 1. Main balanced outputs: 1 on XLR. Record balanced outputs: 1 on XLR. Output level for full-scale digital…
Sidebar 2: Associated Equipment
Digital sources: Wadia 270 CD transport, dCS Purcell D/D converter, dCS Elgar Plus D/A converter, Accuphase DC-101 D/A converter, Wadia 27ix converter, Linn Sondek CD12 CD player.
Preamplifiers: Conrad-Johnson 16LS, Lamm L2, Mark Levinson No.32 Reference, BAT VK-50SE.
Power amplifiers: Krell FPB 350MC, Linn Klimax 500, BAT VK-150SE; all monoblocks.
Loudspeakers: JMlab Utopia.
Cables: Interconnect: Synergistic Research Designer's Reference, Discrete and Active Shielding; TARA The One ISM Onboard; Cardas Golden Reference. Speaker: AudioQuest…
Sidebar 3: Measurements
The Boulder 1012 D/A preamplifier didn't invert signal polarity from either its analog or digital inputs, its analog XLR wiring conforming to the AES "pin 2 hot" convention, while its source impedance was a very low 26 ohms. The volume control operated in accurate 0.5dB steps and the channel balance was superb. With the volume control set to its maximum ("0" on the display), the line-stage gain from the analog output was 20dB, which is perhaps a bit on the high side. Repeating the measurement with a digital datastream representing a 0dBFS, 1kHz tone gave an output…
Similar performance can be seen in the wideband spectra with a very-low-frequency, very-low-level tone (fig.7). Confirming the excellent resolution, the Boulder 1012's linearity error with 16-bit data (fig.8) was superbly low down to below -110dBFS, while its reproduction of undithered 16-bit (fig.9) and 24-bit (fig.10) 1kHz sinewaves was essentially perfect.
Fig.7 Boulder 1012, 1/3-octave spectrum of 10Hz at -120dBFS, V/C = "0," with noise and spuriae (from top to bottom below 20kHz): 16-bit data, 24-bit data (right channel dashed).
Fig.8 Boulder 1012,…
The distortion through the 1012's analog input was superbly low in level across the band, as shown by fig.11, taken at almost 10V into 100k ohms. Fig.12 shows a spectral analysis of a full-scale 50Hz digital tone—the low-order harmonics are each below -100dB (0.001%), and while some higher harmonics can be seen, I suspect that these are actually mathematical artifacts of the analysis. The picture didn't change into 600 ohms (not shown), and even the intermodulation products from a full-scale mix of 19 and 20kHz tones into this punishing load (fig.13) remained below -80dB (0.01%).
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