Op amp upgrade

[Jason Hubbard]

I had problems with my active crossover last night - turned out the design is in two parts, an IO board with buffers and a power supply and a small plug in daughter board containing some densely packed SMT electronics to do the filtering (and the daughter board had become disconnected, all OK now).

Anyway, i looked at the components on the I/O & PSU board - basically 6 x NE5534 opamps, a sprinkling of philips 22uf & 330uf capacitors and a psu built from the classic LM317/337 combination and a string of 6 x 2200uf capacitors.

I was thinking of upgrading the caps to Nichicon FG and replacing the regulators with either a discrete drop-in replacement or simply to change for LT317T/LT337T (which i have a stock of).

Any advice on whether to leave the opamps as is (i don't know how well thought of they are) or to replace them and if so with what?

[Mooly]

The NE5534... I have changed my opinion a little on this one recently... as a "gain block" it's very good, however there are some applications that don't seem to suit it for various reasons.
So without knowing all the circuit details it's impossible to say. Also the 5534 is a single opamp, and "uncompensated" and not unity gain stable meaning that there is an additional capacitor needed for gains below 3. Also, again depending on the exact application, use may be made of the offset null pins to zero out any DC offset.

So if you want to swap them (are they in sockets ?) you need to look closely at the above points.

TBH I don't think you will gain anything from altering the PSU.

[sumaudioguy]

NE5532 and NE5534 are always replaced by me. There are any number that sound better to me like the NJM2068. Others like these old op amps but me and all my buddies do not. Even and LF353 is a clearly better choice (to me) used on the input stage.