Harley Benton TUBE5 Celestion

I didn't have high expectations for this amp. Can cheap be good? I bought it for quiet practice, mostly for clean or little bit overdrived sound. Surprisingly, the sound is not bad at all, especially considering the price tag. I tested it with a >1K€ Gretsch guitar. The sound is a bit boxy, but you can make it darker or brighter with the tone button. The first impression was how much a separate button for low and high frequencies would change the price. But the tone button also works in the appropriate area. The middle frequencies are dominant, perhaps this combo would actually be suitable with an additional overdrive/distortion pedal.
A slightly more unpleasant surprise was with the power button. The difference between 5W and 1W mode is quite small. When I put aside the Vox AC4BL1 (12AU7 tubes in the preamp), the HB 1W was much louder than the Vox with its 4W. The HB amplifier's own drive is quite loud even in 1W mode, if you turn the volume knob past 2PM. But with the clean channel (volume 11AM or so), this amp is absolutely fine, and why not try it even for recording in a home studio.

The celestian speaker is what makes this amp amazing in my mind. The material is nice, it's sturdy. The tone is great, a real little tube amp. It can also be quite loud if you bump up the volume. The only thing I could say is a con is that it doesn't have much for eq(just a single tone knob) so if you wanted to mess around with the treble and bass you really need some stomp boxes. Other than that it is a perfect practice amp, and it's great for the vets who have additional gear to go along with it. Highly recommend for anyone just looking for a bedroom amp or for just practicing and honing your craft :)

Sticked to the end of the cable is a yellow written note, which states “this appliance must be earthed”. It makes me question half an hour of the practice time before i took a notice upon the note. Have i done damage to the amp by not following the instruction? What does it even mean that it should be earthed/grounded? Is the device incomplete?
The look, the feel, and the weight and the sound of it is beyond perfect, though i must say, i have been having issues with humming and constant ticking sound which seems to appear when i don’t lay hands on strings. It seems to wash away as soon as i lay hand on the string and play some notes.
Can someone pour remedy into my problem?

I wanted something just for clean tones and after seeing a bunch of good reviews on this guy I decided to go for tubes instead of digital. Why not right? It's cheap.

For my use it's great. You warm it up and just start playing. I live in an apartment and dont want to disturb my neighbours and this guy is not too loud for that use. If you put everyting on max you might have someone knocking on your door, but leave it at ~50% and you're good.

Features are limited, volume and tone. But I wasn't looking for anything more so I'm happy with that.
It feels sturdy and is not too heavy.

I'm planning to buy some pedals in the future and see how it works with them but as a standalone clean amp it's great.