Update. It is a spring unit.
It's also got a digital circuit with a few functions one of which is valve emulation. Gives a warm valve like tone. It also has overdrive and gain control. Very metal.
The reverb is pretty good. Sounds like being inside a church or large hall.
I've used gear on live gigs in the past not as good as this little amp.
It would be fine in a pub or small hall. Plenty loud enough with no distortion.
I tested all the functions briefly in the video. Sound was picked up using dual lapel mics.
Not the greatest way to collect sound samples but good enough to get a feel for the output.
I may get a muff pedal with delay.