Little dot Mk IV SE not really good, bass gets too loose.

Doublecheck for hair, one small piece of hair can do that.

Compared to X2 560 bass is very fast, articulate and textured and it has very good extension into subbass. X2 has more midbass presence that can be nice but is far from quality of 560. 560 responds very well to eq and u can boost that region to give them more punch.

Nothing special actually. RCA 6AS7G but with adapter and extension to connect external power supply for heaters.

I dont like trolling but in this case +1 :)

I passed information i found here. http://www.ominous-valve.com/russtube.html

Pentagon is symbol of novosibirsk factory so yeah they are soviet.

I guess i did not explain properly? Its not the grille its the big plastic piece in which grille sits.

Help me people problems started. Yesterday i was listening to angels & demons ost and i noticed driver rattle i checked for hair and there was none. Then i removed the grille to see if something got inside the cups and i noticed some clicking sound. When i put headphones on and i press on big...

I would get HE 500 or 560.

I think HE 560 loves double power when going balanced with A28.

Croatia

There is a saying in my country. "There is alot of dust behind a good horse" :=)

https://en.wikipedia.org/wiki/Headphone_amplifier https://en.wikipedia.org/wiki/Damping_factor