After changing the TL064CN in my A119 to a TL074IN and noticing an improved high frequency response and clearer sound I am thinking of doing the same to my A134 VC Panner/Crossfader.
The A134 contains a TL064CN and a TL062CP - are both in the audio path Is it safe to swap these for a TL074 and TL072
more info here regarding the IC swap
http://www.muffwiggler.com/forum/viewtopic.php t=5163