Audible Illusions M3A preamp just stopped outputting any signal

Maybe the mute button?

That's definitely odd. Yes, check all of the obvious culprits first, but if you know it's the AI, my advice is get it checked by someone other than AI. You can get it repaired quicker and for less.

A stuck relay controlling output?

@petg60 does that affect the tape out section?
If the tape or line out, has the signal then that is a hopeful start.

Is there is a way to trouble shoot your hypothesis?

From looking inside your preamp some relays close to tape out and pre out are sited, to be certain that a relay is in signal path somebody has to check the service manual.

What happens if play and mute buttons are pressed, most likely a visit to a good technician may solve it fast.

A total lack of output without anything seeming wrong is almost always user error, I say that from past experience!

Wow, I’m really impressed with all the help. I had forgotten I started this thread until today. Senioritis maybe, haha. It turns out it was user error after all. I remember checking for the mute button But it must have been on during the signal. I tested the same input on the amp with a different source preamp and it worked. For a few days until the power amp died. It was over 30 years old and was a stopgap given to me when my Krell died. So then I thought to test the preamp again and sure enough it worked into my headphones from the line level output.
 

Anyway thanks so much for all the intelligent and thoughtful responses. You guys rock!

Nolan

Dont send to factory

Wow, I’m really impressed with all the help. I had forgotten I started this thread until today. Senioritis maybe, haha. It turns out it was user error after all. I remember checking for the mute button But it must have been on during the signal. I tested the same input on the amp with a different source preamp and it worked. For a few days until the power amp died. It was over 30 years old and was a stopgap given to me when my Krell died. So then I thought to test the preamp again and sure enough it worked into my headphones from the line level output.
 

Well the moron thing to do is to press the mute button and forget.

I know because I always do that when I turn it off 😁
You’ll have a ways to go to beat my record… I must be at moron >= 1 dozen.😂

Hence my first post 😎

Maybe the mute button?

I think it is good to mute it, and I doubt you forget soon.
How do you like your unit by the way? @nolanh 

I am just glad it was a happy ending, and someone else will surely have the same issue and my stumble upon the thread, so it is a pretty good outcome all around.