Network Audio Players/Servers

Users should bear in mind that any analogue source hooked into the CA1000 will pass through a 48kHz/24-bit ADC, limiting its response to –2.3dB/20kHz, the maximum input to 2.2V and the A-wtd S/N ratio to just 80dB (re. 0dBV, any Gain setting). Driving the headphone output via digital files on internal storage offers a markedly superior noise performance while the response is determined by file sample rate and choice of digital filter. Also, while the line outputs retain absolute phase, the headphone output is phase inverting...

But what of power? Fortunately the CA1000 has plenty of it, the maximum available into any load scaling with the four gain settings – 'Low' (–0.4dB), 'Mid' (+5.5dB), 'High' (+9.5dB) and 'Super High' (+12dB). This translates into 7mW/600ohm, 131mW/32ohm and 50mW/8ohm in the 'Low' gain setting all the way up to 126mW/600ohm, 2.1W/32ohm and 815mW/8ohm in the 'Super High' gain setting [black, orange and red traces, respectively, inset Graph]. A&K's specified maximum single-ended voltage output of 8V is met at 8.6V as is the 0.005% THD at 0.0008%/1kHz/1V (all unloaded). Distortion does increase with loading and gain setting [again, see Graph] from 0.001%/600ohm to 0.02%/32ohm and 0.11%/8ohm (all 10mW, 'Super High' gain) but, crucially, its super-low 1.1ohm source impedance means the CA1000 will deliver this power with minimal loss or variation in freq. response with the toughest headphones. PM