Hi there Ichil, good morning, thanks for the reply, ok, let's check:

1. Guitar and amp only: there's sound?
Yes, actually, I have a few analog pedals running thru the loop of the amp and that works great, so, it's not the amp with a faulty return jack input or something.

2. Standby is off on the amp?
Yes, the way it should be

3. Did you try a mono patch?
4. The effects loop of the amp is at -10dbV?
5. You can get signal out of the emulated output?

Those last 3, do you mind to guide me on that? I mean, I don't know how to try a mono amp or how to get a signal out of the emulated output.

Thanks so much!