301/307

[KA4HJH]

Rowena wrote:
>I am looking at fixing up an old synth.
>The circuits say that the op-amps should be LM301. The person who built
>the synth has used LM307.
>
>How compatible are these chips?
>
>The 307 is internally compensated. Does that mean that the frequency range of
>the chip is not suitable for a synth?
>
>Should I rip out the 307s and replace them with 301s?

I assume that the synth more or less worked at one time. If a circuit
doesn't exceed the 307's slew rate there MIGHT not be a problem in that
instance. It would be useful to know what the external compensation is, if
the component(s) are still/ever were there. Some more info on this gadget
would make judgement calls easier.

The safest thing, of course, would be to use the correct IC's (and external
compensation, if the parts are missing). If you really want performance,
you could always substitute a 201 or even better a 101, although then you
might have to tweak the compensation for a higher slew rate--this is
quickly getting out of my league, I'll quit while I'm ahead...

Terry Bowman, KA4HJH
"The Mac Doctor"