Digital Sources: NAD M50.2 music server; Ayre Acoustics QX-5 Twenty D/A processor/headphone amplifier; 160GB iPod Classic, PonoPlayer, Astell&Kern A&ultima SP1000 personal players; iPhone 6s; Ayre Acoustics C-5xeMP disc player.
Headphone amplifier: Pass Laboratories HPA-1.
Headphones: Audeze LCD-X, Ultimate Ears 18 Pro.
Cables: Digital: AudioQuest Coffee (USB), Canare (AES/EBU), Esperanto Audio (S/PDIF). Headphone: Cardas Clear, Surf Cable, manufacturers' own. AC: Audio Power Industries (components), AudioQuest NRG-2 (Niagara 1000).…
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I didn't measure the Audezes' frequency response, as I don't have the necessary simulated head and torso, and estimating the optimal response of headphones is far from simple (footnote 1). However, I used my Audio Precision System One to measure the Audeze LCDi4s' impedance and electrical phase. The solid trace in fig.1 shows the impedance magnitude with the headphones inserted in my ears. The impedance is a constant 26.7 ohms across the audioband, and the phase angle is 0° up to 10kHz, suggesting that the planar-magnetic drive-unit behaves as a pure resistor up…
Listening
The Heed manual advises settings of 100µV sensitivity and 100 ohms impedance for the Denon DL-103. After I'd…
Description: Solid-state moving-coil/moving-magnet phono preamplifier with standalone power supply. RIAA accuracy: 20Hz–20kHz, ±0.5dB. Frequency response: 3Hz–150kHz, ±3dB. Voltage gain: 50dB (MM), 62–78dB (MC). Moving-coil sensitivity: 100, 220, 600µV. Input impedance: 47k ohms (MM); 100/470/1000 ohms (MC). Output voltage: High Out, 775mV (0dBm)/22 ohms; Low Out, 220mV/100 ohms. Maximum output voltage: 7V (p–p). Output impedance: 50 ohms (High Out), 600 ohms (Low Out). Signal/noise (A-weighted): 80dB (MM), 66dB (MC). Channel separation: >90dB. Distortion (…
Analog Sources: Kuzma Stabi S turntable & Stogi tonearm; Music Hall MMF-7.3 turntable; Denon DL-103 (MC), Goldring Elite (MC), Ortofon 2M Bronze (MM) cartridges.
Digital Sources: Apple MacBook computer running Audirvana Plus; Halide DAC HD, PS Audio NuWave, Mytek HiFi Manhattan DACs; Western Digital T2 Mirror Drives (2), LG BD550 BD player (as transport).
Preamplification: Auditorium 23 A23 moving-coil step-up transformer, Shindo Laboratory Allegro preamplifier.
Power Amplifier: Shindo Laboratory Haut-Brion.
Integrated Amplifiers: Heed…
I measured the Heed Audio Quasar phono preamplifier using my Audio Precision SYS2722 system (see the January 2008 "As We See It"). As always with phono stages, I experimented with the grounding between the preamp and the Audio Precision system to get the lowest level of noise. I ended up floating the Audio Precision's outputs from ground and connecting the Quasar's grounding post to the analyzer ground.
The Quasar preserved absolute polarity with both moving-coil and moving-magnet settings and inputs, and from both its High and Low outputs. There are…
Here’s our second (of three) video show reports from the New York Audio Show that took place earlier this month at Manhattan’s Park Lane Hotel.
After monitoring the feedback on our first video report, I realized that I should have been clearer about the footage in the room. For those of you who were concerned about the placement of the microphones from the different types of footage of Herb listening, please understand that it’s difficult for us to…
John Atkinson, too, is a hard man, at least when it comes to audio gear. When, in January 2014, he reviewed the Pass Laboratories XA60.5…