Vintage 1977 Sharp/Optonica high-end audio amplifier with three transformers
Vintage 1977 Sharp/Optonica high-end audio amplifier with three transformers
Launched by Sharp in 1975, Optonica was to Sharp's high-end audio display, much like Technics was to Panasonic.Becoming really visible in '76/77, Optonica however came up just a bit too late to get a firm grasp on a market that was about to slide down after 1978...If Optonica is well remembered for its 1980/81futuristic designs, often embodying the electronic audio & design research Sharp was heavy into, it made excellent separates before its most "visible" peak.The SM-4646 is one of those efforts, available in silver (SM-4646H) or black (SM-4646B).Three power transformers for "Delta Power", DC Class A stages (preamp + pre-driver), two big 13,600µF main caps, low-noise FETs & differential amps everywhere, a 4-gang volume attenuator and 16kg in toto.The center transformer feeds the preamp and driver stages in Class A, the other two, independently, the L and R output stages in Class B.It doesn't look like that from the outside, right ?Indeed - but either it wasn't enough to start trekking the upper part of the scale or too much to keep low prices and get a strong grip onto the mid-end market...Looks-wise a bit heavy and mostly clearly leaning toward the 1960s instead of the upcoming 1980s, too. Which is quite charming.Despite receiving a french Laurier d'Or (Golden Laurel) for "outstanding function, design and performances" in 1977, Sharp's Optonica series never sold much... in France or elsewhere - pity.
1977
Vintage 1977 Sharp/Optonica high-end audio amplifier with three transformers