Back in 1980, Japanese manufacturers were engaged in mortal combat trying to make the cleanest and most powerful transistor amplification yet devised. Whereas Sony and Yamaha had both recently gone down the V-FET route (with the TA-N7B and B2 respectively) and Pioneer was sticking to Class AB bi-polars with its massive SPEC-2, Marantz was firmly in the Class A camp with a range of new-fangled MOSFET power amps. The MA-5 was the company’s premium ‘Esotec’ monobloc model – the name given to its top range of products which also included another notable design, the TT-1000 turntable.
Each champagne gold coloured, ‘half size’ 208x146x334mm box packed 120W RMS into 8 ohms (at 0.01%THD), while a flick of a rear-mounted switch converted the MA-5 from Class AB to full Class A, whereupon it delivered a not inconsiderable 30W into 8 ohms (at 0.008% THD). Inside, chunky power transformers, 44,000µF of capacitors and a brace of 2SD757/ 2SB717 MOSFET devices accounted for the not inconsiderable 10kg per unit. Power consumption was 230W per monoblock, so it wasn’t something you’d want to leave on all the time! At the front, a neat cover pulled out of the chunky brushed aluminium front panel to reveal a hidden power switch and gain control. A row of green LED peak meters, with dual scale calibration (for Class A and Class AB) showed how hard those MOSFETs were working, and there were LEDs to denote Class A or AB operation too.
Even by today’s high standards, in Class A mode the MA-5 is a lovely performer. There’s little that can touch pure Class A done properly, and the Marantz proves exemplary, sounding ultra-neutral, fast, detailed and with great tonal colour. Importantly, it sounds open enough to let any instrument’s true tonality shine through. These little golden monoblocks don’t perform like a thirty five year old design, as they’re highly incisive, transparent and dimensional with real rhythm and excellent dynamic accenting. The only weak point is an ever-so-slightly light bass and unatmospheric treble. Overall, the classic Marantz MA-5 is a superb classic product, perfectly able to cut it in today’s world – so it must have been exceptional in its day.