Which External Linear PSU Upgrade for my Router?

I use this. It has 2 outputs if you need to power something else that's the same voltage. I got the premium version for the extra couple bucks.

https://www.aliexpress.us/item/3256805431512321.html?

I replaced my two (modem and router) LPSs from Aliexpress (complete with iFi DC Purifier and Bybee iQSE) with a 12V deep cycle automotive battery, which is only charged when not playing music. Moved my listening experience from mid-audience to front row seats!

I'm convinced that digital electronic equipment (in particular) are hypersensitive to the quality of input power and acoustic vibration. 

For routers, switches and NAS, I have found some LPS do not work so well, and can be worse than the included SMPS. I think its due to the fast high frequency nature of the network switches.

But some of those LPS that did not work well with switches were fantastic with DAC's and streamers. So you need to experiment and not presume any LPS is an upgrade..

Thanks heaps for your suggestions. I’ll look into these and see how I go. 

These are on higher price points, but will also deliver on a higher level of performance:

Farad Super3, around $550-700

Ferrum HYPSOS, around $1200-1400

The Ferrum option is very versatile as it allows you to customize the voltage should you want to use it with another component down the line. They also now make a dual output device as well so you can power two components that have the same voltage. 

In my system, I found the performance of the Ferrum Hypsos to be above that of the Farad, so I became a Ferrum dealer.

Lots of reviews of both online.