[marssaxman]

This kind of device is called a "compressor", and they are ubiquitous in recording studios. They can get very expensive and complicated, but for your purpose something like this may suffice:

https://www.amazon.com/rolls-SL33B-Stereo-Program-Limiter/dp...

Specifically what you want is a "stereo compressor" or "compressor/limiter"; if you want something more sophisticated than the device above, there are many 1U rack options available for ~$200 (dbx is a good choice), or used on reverb.com more like $70-$100.

[ghoomketu]

Thank you. Appreciate the reply. These gadgets are rather costly tbh. I did some digging around on YouTube for the compressor and I found this:

https://youtu.be/d3XxckqoeXE

Is it doing the same thing? Seems rather easy and cheap to make.

[marssaxman]

That is a clever design, and yes, it's doing the same thing. If you have electronics assembly skills, why not? Sounds like fun.

There's no reason a simple compressor suitable for your purpose should have to be expensive; there just isn't much of a market for such a device.

If you're open to used gear, another good option would be an Alesis Nanocompressor - available in the $70-$90 range: https://www.ebay.com/sch/i.html?_nkw=alesis+nanocompressor&_...