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Discussion Starter #1
Weird question here:

I have a couple amps for my front stage that were being used with my MS-8 for a while. The MS-8 has ~2.5V outputs. Recently, I changed to just using my new 9887 which has 4V outputs. The day I made the change, I had issues with both amps going into protect after a while (assuming just from the higher voltage input, neither amp was hot) even after backing the gains down.

A few days later, I turned the gains back up to AT LEAST where they were before, played the system longer and harder than before, and haven't had a single issue since. It's like the amps didn't like the initial shock of the higher voltage, then got used to it.

What really happened here?
 

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It depends on the amps, I have an alpine that has an automatic gain. It can be changed in steps but you are supposed to follow a procedure so it sets it auto, then change the other one if you need to. However if the amp had the gains higher it would have been louder (at the same HU volume). I don't know of any old amps that do this, the alpine I have is under 10yr old I'd guess and has digital controls.
 

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In that case I have no idea. Usually preamps are rated for X input voltage and that is that, based on the opamps and design of the preamp.
 

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Hmmmm, that would point to some other error. Most amps protect for shorted speaker, low or high input voltage on the 12v, DC current to the speakers, some for other things. I don't know how many protect for input signal issues, though some now take the low impedance input (HU speaker wire) right into the RCA and sense what input is there.
 

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amplifiers are not biological, lol. had to be other issues causing the protect.
 

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Discussion Starter #9
Hmmmm, that would point to some other error. Most amps protect for shorted speaker, low or high input voltage on the 12v, DC current to the speakers, some for other things. I don't know how many protect for input signal issues, though some now take the low impedance input (HU speaker wire) right into the RCA and sense what input is there.
Nothing has changed at all in the wiring. No speaker shorts, car was running so the amps had at least a solid 13.8V. Just using RCA's straight from my 9887 to the amps. No speaker level inputs or anything.
 
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