Vintage

Both the 928 preamp and 928 monoblock power amps perform precisely as promised in Primare's literature from 1986. The preamp offers a +20dB overall gain (or +14dB in the '–6dB' position), its balanced output delivering a maximum 22V from a vanishing low 1ohm source impedance. Distortion [black trace, Graph 2] is low at between 0.0004–0.0016% (20Hz-20kHz, over the top 3V of its output). Noise is also low and the S/N acceptably wide at 94dB (re. 0dBV) while the response is flat within ±0.02dB from 100Hz-100kHz. There's some tailoring at very low frequencies with a very gentle 'shelf' starting at 100Hz and reaching –0.25dB/50Hz and –1.0dB/20Hz. The 'Low Cut' option operates below 20Hz with –6dB/12Hz and –18dB/7Hz.

The partnering 928 power amp is a fully balanced design where Primare claims to have 'eliminated negative feedback'. The flat 0.13-0.14ohm output impedance is not worrisomely high, as might be the case with no feedback, and the response very extended from 3Hz-70kHz (–1dB), but the lack of conventional compensation is revealed in the long warm-up time where THD slowly reduces from 0.7% (1kHz/0dBW) down to 0.08% over 30mins and to 0.035% over 60mins. Once stabilised, distortion is a consistent 0.04-0.06% over the full 20Hz-20kHz audio range [red trace, Graph 2] over the first 20W of its output. From 20W to the rated 100W/8ohm, THD climbs gently to 0.25% [black trace, Graph 1]. In practice its power delivery is prodigious and the PSU astonishingly 'stiff' as evidenced by the 140W/8ohm and 270W/4ohm output. Its supreme speaker load tolerance is also illustrated by its dynamic output capability of 140W, 280W, 530W and 955W into 8, 4, 2 and 1ohm loads [Graph 1]. PM