Eeyore wrote:

APR wrote:

What difference would you expect a different IC to make over the
4558's?

Just to put this into perspective, the 4558 is little better than the
rightly maligned (today) 741 op-amp.

Hnmm ... it doesn't have enough treble to actually distort, unlike the 741
that had too much, otoh it is not spitty, just plain boring. There are
plenty plug and play alternatives ... but whomsoever plays the opamp upgrade
game should unsolder what is there CAREFULLY, you may need that exact opamp
for the circuit to work, and put good sockets in to avoid having to solder
multiple times on the pcb.

Graham

Kind regards

Peter Larsen