Ah, a Takács Quartet recital. Another few months gone (the violist-groupie in me thinks), another rare chance to hear Geraldine Walther play. Only I find that I'm not really thinking about the Takács' visits like that anymore. Walther is a great violist, but the Takács with her in it is something more interesting — a great quartet, and one that seems to become greater by the minute. Sunday's all-Beethoven recital, presented by Cal Performances at UC Berkeley's Hertz Hall, the last we'll hear from this quartet for some time locally, found the players working at a fearsomely high level. Every time I hear the Takács in its current lineup, I marvel anew at how singularly effective its improbable combination of colors is. The two non-Hungarians — first violinist Edward Dusinberre and violist Walther — sound like they come from one timbral tradition, second violinist Károly Schranz and cellist András Fejér, from another one. And yet, what you actually hear is a magnificent unanimity of expression and intention, spiced with just enough independence of line to keep the texture constantly alive and interesting. Dusinberre's light, lithe violin and Walther's heady viola are the dominant colors, but Schranz's meatier sound lends its own cast to the upper-string color, while Fejér's obstreperous cello gives the whole thing a salutary kick in the pants from below. Sunday's Beethoven (early, middle, and late) gave every element of that interesting melange a place in the sun. In the F-Major Quartet, Op. 18, No. 1, it was the remaining founding members who seemed to provide the motive power — especially Fejér, whose irrepressible energy stamped the entire performance. In the "Harp" Quartet, Op. 74, by contrast, the heart-stopping moments belonged to the other two players. Dusinberre's dashing account of the first movement's long, brilliant coda was topped only by Walther's gloriously sung playing of the "viola variation" in the finale.