Audio: High-fidelity sound emanates from smaller, modular systems; innovations are seen in tape recorders and turntables

Until recently many audiophiles assumed that high fidelity could be achieved only with large, bulky equipment. Squeezing audio technology into anything smaller than a breadbox degraded performance, they felt. Since the introduction of Sony's Walkman stereo audio-cassette player two years ago, other manufacturers have also packed higher-performing hi-fi into smaller enclosures. What's more, all of the smaller units needed to put together a hi-fi system are now available from the same manufacturer Formerly, customers had to hunt among different manufacturers for the best combination of tuner, amplifier, turntable, tape deck, and speakers.