An amplifier remains the beating heart of any high-performance audio system, but in 2018 a truly versatile integrated amp needs to cover many bases – digital and analogue sources, wireless connectivity for portable devices, a phono stage to cater for vinyl playback, amplification for headphones as well as speakers… That’s a lot to pack in, whilst keeping performance high and the price tag affordable – and yet, that’s exactly what the 6000A delivers.
The Sound of Science
Outwardly, the 6000A bears strong resemblance to the 8300A with its rotary controls and large, central OLED display. Unlike its costlier, analogue-only sibling, it incorporates high-quality D/A conversion, enabling digital sources to be connected directly without an external DAC. It supplies four digital inputs, three line-level analogue inputs, an input for a turntable, wireless connectivity via Bluetooth and a dedicated headphone amp, in addition to its ability when driving loudspeakers.
Much effort has been made to ensure the 6000A’s digital circuitry delivers the level of quality one might expect of a high-performance standalone DAC. As ever, Audiolab has turned to the ES9018 Sabre32 Reference chip family to perform D/A conversion, utilising ESS Technology’s 32-bit HyperStream architecture and Time Domain Jitter Eliminator to deliver ultra-low noise and high dynamic range.
No company knows more about making the most of this technically excellent, but challenging, DAC technology than Audiolab.
The 6000A’s discrete Class AB power amp stage delivers 50W per channel into eight ohms, with a maximum current delivery of 9 Amps into difficult loads. The output stage of the discrete power amp circuits uses a CFB (Complementary Feedback) topology, ensuring superior linearity and excellent thermal stability, as the idle current is kept independent of the temperature of the output transistors.
A substantial 200VA toroidal transformer, followed by 4x15000uF reservoir capacity (60000uF in total), helps the amp to maintain firm control of the music whilst enabling excellent dynamic range.
The preamp section is kept as simple as possible to maintain signal purity, with line input signals passing to a precision analogue volume stage. The latter covers the range from -80dB to +8dB in steps of 2dB and 1dB (step resolution increases with volume position). Much effort has gone into the physical layout of the 6000A’s circuitry, protecting the sensitive preamp section from noise interference.
Gain (max.) +8dB (Line) +55dB (Phono MM) Input Sensitivity 720mV (Line, Volume = 0dB) 3.1mV (Phono MM, Volume=0dB) Input Impedance 10K (Line) 47K//100pF (Phono MM) Total Harmonic Distortion (THD) < 0.0004% (Line, 1KHz @ 2V, Volume = 0dB) Frequency Response 20Hz-20kHz (+/-0.1dB) Output Voltage 2.3V max. (Volume = 0dB) Output Impedance 120Ω Signal-to-Noise Ration (S/N) > 110dB (Line, A-weighted) >76dB (Phono MM, A-weighted) DAC D to A converter ES9018K2M Total Harmonic Distortion (THD) < 0.0006% (1kHz @ 0dBFS) Output level (0dBFS, 1KHz) 2.05V Max. Sampling Frequency 192kHz Signal-to-noise ratio (S/N) > 112dB (A-weighted) Digital Filters Fast Roll-off , Slow Roll-off , Minimum Phase Power Amplifier Section Gain +29dB Rated Max. Power Output 2 X 50W (8Ω, THD<1%) 2 X 75W (4Ω, THD<1%) Frequency Response 20Hz-20kHz (+/-0.3dB) Input Sensitivity 720mV Total Harmonic Distortion (THD) <0.003% (1kHz @ 40W/8Ω) Signal-to-Noise ratio (S/N) > 110dB (A-weighted) Max. Output Current 9A Headphone Amplifier Total Harmonic Distortion (THD) < 0.01% (1kHz, 50mW) Output Impedance 2.35Ω Load impedance 20-600Ω General Standby Power Consumption <0.5W Power Requirements 240V ~ 50 - 60Hz 230V ~ 50 - 60Hz 115V ~ 50 - 60Hz 100V ~ 50 - 60Hz Dimensions (mm) (W x H x D) 445 x 65.5 x 300 Carton Size (mm) (W x H x D) 512 x 467 x 146 Weight 7.8kg (Net)