Suffice it to say that I was so impressed by that brief interlude that I wanted to know more about Boulder. I went to the company's factory in Boulder, Colorado, and watched them mill metalwork, stuff circuit boards, and assemble components—all in-house. The impressively clean facility clearly represented millions in…
Description: Solid-state, remote-controlled, class-A/B integrated amplifier. Frequency response: 20Hz–20kHz, +0.0/–0.07dB, 0.015Hz–95kHz, –3dB. Maximum continuous output power: 150Wpc into 8 or 4 ohms (21.9dBW, 18.9dBW), 300Wpc peak into 4 ohms (21.9dBW). Maximum voltage gain: 46dB. THD at maximum continuous power: 20Hz–2kHz, 0.0035%. Signal/noise ratio: 108dB unweighted ref. 150W into 8 ohms, 20Hz–20kHz. Maximum input level: 6.0V. Input impedance: 100k ohms balanced, 40k ohms unbalanced. Common-mode rejection (balanced): 60Hz, 90dB; 10kHz, 70dB. Crosstalk: –…
Digital Sources: Ayre C-5xe universal player, Simaudio Moon Evolution SuperNova CD player.
Preamplifiers: Ayre K-1xe, Parasound Halo JC 2, VTL TL-6.5 Signature.
Power Amplifiers: Parasound Halo JC 1 and VTL MB-450 II monoblocks.
Loudspeakers: floorloudspeakers/1208thi">Thiel CS3.7, Klipsch Palladium P39F, YG Acoustics Anat Reference II Professional.
Cables: Interconnect: Shunyata Research, Stealth Metacarbon (balanced). Speaker: Shunyata Research, Stealth Dream. AC: Shunyata Research Python Helix Alpha.
Accessories: Ayre Acoustics Myrtle…
I examined the Boulder 865's measured behavior using mainly Stereophile's loaner 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.
Before performing any tests on an amplifier, I run it for 60 minutes at one-third its specified power into 8 ohms, which is thermally the worst case for an amplifier with a class-B or -AB output stage. The Boulder's top panel was quite warm at the end of this period, but soon thereafter…
Have the person you're arguing with inspect the fit'n'finish of this handsome, 45-lb powerhouse, and finger the rugged heatsinks flanking its chassis. Encourage that audiophile to pop the heavy top plate and examine the superior build quality and parts (including WIMA…
Apparent almost immediately were a spare quality to Young's voice, and a very fast hall reverberation that appeared whenever he lingered between phrases. Not a great deal of depth developed behind his voice, nor was his guitar notably supple and pure, but the…
Description: Tube and solid-state, remote-controlled, two-channel integrated amplifier with six line-level inputs. Tube complement: three 12AX7. Maximum output power outputs: 150Wpc class-AB into 8 ohms (10Wpc class-A), 250Wpc class-AB into 4 ohms. Frequency response: 20Hz–50kHz, ±0.5dB. Input sensitivity: 200mV. Input impedance: 47k ohms. THD: <0.1% (1kHz at 1W). Signal/noise ratio: 80dB (no reference level given). Power consumption: not specified.
Dimensions: 16.8" (430mm) W by 5.9" (150mm) H by 17" (435mm) D. Weight: 45 lbs (20.4kg).
Serial Number Of…
Analog Sources: Continuum Audio Labs Caliburn/Cobra/Castellon turntable/tonearm/stand; VPI SuperScoutmaster Reference turntable; Graham Phantom tonearm; Lyra Titan i, Koetsu Coralstone Platinum mono, Shelter 7000, MySonic Hyper Eminent phono cartridges.
Digital Sources: Musical Fidelity kW DM 25 transport & DAC, Cary CD 306 SACD Professional Version SACD player, BPT-modified Alesis Masterlink hard-disk recorder.
Preamplification: Manley Steelhead, Einstein Turntable's Choice, Audia Flight phono preamplifiers; darTZeel NHB-18NS preamplifier.
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I used the top-of-the-line Audio Precision SYS2722 system (see the January 2008 "As We See It" and www.ap.com) to measure the Vincent SV-236MK; for some tests, I also used an Audio Precision System One Dual Domain.
As usual, before performing any tests, I ran the Vincent for 60 minutes at one-third its specified power into 8 ohms, which is thermally the worst case for an amplifier with a class-B or -AB output stage. The measured distortion+noise was 0.021% with the amplifier cold; at the end of the hour's preconditioning, it had risen inconsequentially, to…