Integrated Amplifiers

There was a time (BCD – Before CD) when tape and tuner line outputs struggled to reach 500mV, and the overall gain – the amplification factor – of integrated amplifiers was often as high as 40-45dB (x100 to x178) to accommodate such feeble levels. Modern line level sources including DACs, disc players and even phono stages rarely offer less than a 2V maximum output these days, so high levels of gain in a partnering integrated amp are unnecessary. Nevertheless, very few amp brands have engineered a reduced level of gain, despite all the advantages in noise and distortion this might bring.

Constellation [HFN Dec '17] is a rare exception, but YBA is all but unique in offering just +23.6dB (x15 via its balanced input) with its IA350A. This explains why the finest ±0.5dB steps of its volume control operate over the top 30dB of its dynamic range (0 to –60 on the volume scale), before dropping to ±1.5dB steps over the next 15dB (–61 to –70) and coarser steps to complete a full 75dB dynamic range at –79 on the volume scale. But there's another reason why the IA350A sounds so rich and smooth – it has a 'shaped' frequency response with a +1dB bass boost operating over its lowest four octaves coupled with a 'sweetened' treble of –0.25dB/10kHz and –0.45dB/20kHz [see inset Graph]. PM