these are custom programmed and a universal remote will not work with the preamp.
If it’s a learning universal remote it should be able to learn any code, custom or not. If you like your pre it’s surely worth a try, and again with Amazon if it doesn’t work you can easily return it. I’d try this one for 10 bucks and just see — my guess is it will learn the Herron codes…
https://www.amazon.com/Chunghop-Universal-Learning-Function-L336/dp/B07C97YBBC

