LM2902 substitute

[disorder]

I'm fixing up an old Roland phaser that uses two LM2902 and the one used for LFO seems to have failed with all outputs near the rails. It's a real old pedal and oddly enough it seems like the LM2902 architecture is still in use today as an SMD part. It's grouped in with LM324, the main differences I can see are max supply voltage and operating temp. Before I put a socket and an LM324 in this pedal is there a more suited replacement? I worry today's LM2902 is related to the old LM2902 only in name. 

[GGBB]

The PDIP-14 LM2902N is readily available from Mouser and other places.

[anotherjim]

LM324 is a perfectly good replacement. What I've seen of those Boss pedals is they do not have reverse polarity power protection. Someone touching a battery on the snap the wrong way around can fry one or more of the chips.

[StephenGiles]

I think that the EH Riddle uses a quad opamp in the LM29xx series.

[PRR]

> all outputs near the rails

You don't say you checked Vref or the input pin voltages. Depending on bias, a Vref failure sure could throw all outputs high.

> LM2902 ..grouped in with LM324, the main differences I can see are max supply voltage and operating temp

Yes, classic LM2902 can still be found.

LM2902 and LM324 are the "same" chip. First digit is traditionally:

1- Military (very wide temp, very tight spec)
2- Industrial (wide temp, tight spec)
3- Commercial (shirtsleeve temp, reasonable spec)

The LM324 is not sexy and was not sold into Military markets. So I've only seen the 3__ grade (and a listing for a LM124, but maybe not really available).

A particular application is Automotive. This needs nearly full Industrial Temp range, but without tight specs, and no need for full 40V breakdown, 12V-15V ought to be fine. A '2902 is a '324 die in industrial plastic and a slightly reduced voltage rating to cover extreme temps without costly processing.

I think at one time the '2902 was cheaper than '324, leftovers from some automotive many-millions production. That may be why 9V pedals used '2902. (Not because they expected to play in sub-sub-Zero temperatures, like your car engine might face.)