NE5532 decoupling capacitors

[Markw4]

True

 

[DSP_Geek]

Latching relays aren't appropriate for speaker protection as you need to know the relay is open-circuit at power-up. Relays able to handle 100% duty cycle without cooking themselves definitely exist!

I'm thinking not so much speakers as preamp output mutes, where energizing the relay disables a short between output and ground. Power cycle the preamp once to put the relay in a known state. Seemples!

 

[benb]

This may be slightly off topic but I think it's important.

Some opamps also need correct sequencing of the power rails. The 5532 is a case in point, needing a few volts on the negative voltage before the positive is connected to prevent a big output transient.

This was (no longer made, much like most of the SSM/CEM chips from the 70's/80's, though other makers are now producing replacements as the article below describes) admittedly a specialty chip used in music synthesizers (some of them could possibly have been used in non-music applications such as a signal/function generator, but I've never heard of such use), but the SSM2164 had a big fault in power supply sequencing:

They’re also thinking of producing a version of the SSM2164, the SSI2164. I await developments there with interest, and I hear that they’ve fixed a problem in the original chip which causes it to self-destruct if the negative supply is removed.

https://electricdruid.net/analog-renaissance/