A relay in your audio path? Can’t imagine that before, although the practice is quite common on commercial audio application.
The function of the relay in your audio path is to prevent any unstable (or unpredictable) condition which may happens in your equipment during the power up session. Normally, some of your equipment will produce pop or thump sound during the power on due to inrush current or spark on the power switch. If there is no relay on your audio path, this kind of sound will directly hit your speaker. Although not commonly happens, if happens, it could damage your speaker.
I’m a kind of guy who doesn’t care about this before, but now I’m thinking to have it. Why? I think it’s time for DIY to learn how to make all the things professionally. Not just based on his/her own ego. If you don’t like it, try to solve it, not to avoid it. I know best fuse is no fuse at all, but compared to the risk, I prefer to use the fuse.
This project is still under development. The idea is still under experimental stage, not yet published.
First thing first, we have to find a good relay.
Well, there is some relay specified on the signal path. But they are rare and quite expensive. I will start with a cheap and easy to get brand, Omron. I prefer the one with copper bar, probably better than other metal type.
Omron has some models, from different country. Below is bigger one, up to 10A, while above is smaller one, up to 5A.
The idea is to modify the relay so it could be acceptable on the signal path. How we are going to do that? Well, it’s still under experimental stage and I’m testing some possibilities.
I also purchase a speaker protector kit (time delay and DC offset detector). I remove the DC feedback detector since I don’t need that, so I just use the startup time delay function. And off course, we will upgrade the relay with the new “modified” one.
I will update some more once I got more “proven” result.