The customary listing of performing personnel is nowhere to be found in the Juilliard Quartet's new three-disc set of Haydn's Op. 20 string quartets (the six so-called "Sun" Quartets, Columbia M3-34593), although full production, engineering and illustration credits are given.

Since Steven Epstein is identified as producer, it seems safe to assume that this is a very recent recording, involving the Juilliard's current lineup -- Robert Mann and Earl Carlyss, violins; Samuel Rhodes, viola, and Joel Krosnick, cello who may be congratulated, and thanked, for what may well be the finest addition to this group's discography since it was initiated nearly 30 years ago by Mann and three different associates.

The Juilliard has not always performed up to its own standards in the recording studio. There have been some disappointments during the last dozen years or so. But there is a spirt of regeneration in evidence here, which seems to transform the sunburst on the cover from a mere illustration to a particularly apt symbol. the readings, in all six works, are at once vital and expansive, crisply articulated and filled with warmth of heart. The playing itself, on the technical level, is the handsomest the Juilliard has given us, through its various personnel charges, since the stereo remake of the Bartok quartets [Columbia D3S-717] some 15 years ago.

And what quartets these are, after all. We do not hear them often: No. 4 in D major [actually the last of the six to be composed] is the one most frequently performed, and even that is hardly "overexposed." H.C. Robbins Landon, in his characteristically illuminating annotation for the set, makes a strong case for the importance of these six works, pointing out the intricacies, ironies and general inventiveness of their construction. The most compelling argument, however, is Haydn's own, stated with incomparable eloquence and conviction by the Julilliards, whose radiant performances are set off in vivid, wellbalanced sound.

Collectors who already have the Tatrai Quartet's recording of Op. 20 [Qualiton SLPX 11332/34] need not feel at all unhappy about that. The cycle of Haydn's quartets this Budapest group has been committing to discs since the mid-'60s is one of the most successful undertaking of its kind, and each new segment has served as a further validation of the exceptional levels of authority and commitment at work in its production. While I would probably choose the Juilliard over the Tatrai for Op. 20, I would be quite happy with either, and the Tatrai's new set of the Op. 33 Quartets [Hungaroton SLPX 11887/89] is definitely a winner.

It was surprising to check the catalogues and find there is no other intergral recording of this demi-dozen available here at present, but the Tatrai performances are of course more than mere gap-fillers. The only one of these six works I can remember enjoying more than I did in my first few hearing of this new set is Op. 33, No. 2, in E-flat: The old Pascal Quartet version, on an old Musical Masterpiece Society 10-incher, deleted more than 20 years ago, was incomparably infectious, and anyone lucky enought to have a copy must treasure it. Otherwise, all six works in the new Tatrai set are presented with all the understanding and elegance that have distingushed the earlier installments in this splendid series.

There have been recordings of Op. 33 in which the six works were made to fit on two discs instead of three by making "sandwiches" in which one quartet one each disc was interrupted for turnover. That is not a stisfactory arrangement, and I cannot imagine that anyone would begrudge himself the additional outlay for the convenience of having one complete quartet, and only that, on each record side. One rather less convenient aspect to the Qualiton/Hungaroton sets is their persentation of the respective quartets in strict chronological sequence instead of the familiar numerical one; at least the numbers are shown in this set.