You could help yourself and use the search engine. All that gear and much more has been talked about. If you serious, don't buy based on what you read pn the internet. Get a hold of them and listen.

There are many ways to obtain gear to evaluate if your serious.

Thanks, sorry my English, but if it is not much bothered which of the two would prefer the Avalon or the Universal

I prefer the API 3124.

Between the Avalon and Universal for a preamp, Universal.

I agree w audiogaff on the UA over the Avalon.
I also agree that if you're going to spend big $ for a nice preamp, find a way to listen & compare. If you're near a big city, see if you can find rental. If you're near a pro audio store, see if you can try before you buy. If you tell them you are serious about buying a $1500 mic pre they might be willing to set up an A/B listening session or let you try some things out at home before you make a final decision.
If all else fails, find a recording studio that will let you come in & try different pres for a reasonable rate.

What are you looking for that you are not getting from the API?

"You could help yourself and use the search engine. All that gear and much more has been talked about. If you serious, don't buy based on what you read pn the internet. Get a hold of them and listen.

There are many ways to obtain gear to evaluate if your serious."

Exactly. You can spend months or years listening to other peoples often limited/biased opinions and drive yourself mad. Another good option to start with and try to narrow down your options at least, might be to get the 3d mic pre CD, i bought the preamp summit, and it is really pretty cool.