Thanks for the detailed responses.

I swapped the TL064CN and a TL062CP for TL074 and TL072 but did not hear a significant difference. I hear something in the high end, a tiny bit more detail but since the test is not blind I don't know if I am making that up. Technically I should hear a difference with unfiltered waveforms so I will stick with the TL07x until I can get a hold of some Burr-Brown opamps to try.

-Haven

--- In Doepfer_a100@yahoogroups.com , <yahoo@...> wrote:
>
> > 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
>
> It's no problem to replace an TL06x by TL07x or TL08x. In the first A-100
> modules we wanted to keep the power consumption as low as possible and
> therefore predominantly TL06x were used. In all newer designs the TL06x are
> mainly used in CV paths. In the audio circuits TL07x (or others like NE5532,
> LFxxx, OPxxx).
>
> Best wishes
> Dieter Doepfer
>