Line Magnetic quality

The Cayin (aka Zhuhai Spark Electronic Equipment Co) brand gave birth to LM. Legend has it that the two brothers were engineers at Cayin, then struck out on their own. I've been told they source many parts from the same suppliers and have similar build quality. I have an early Cayin integrated, supposedly engineered by the LM brothers, that's now going on 12 years old. It operates as new and is built like a tank. Except for the bias boards, it's all hand-wired with a very tidy layout. It has only high quality parts: Takman, Nichicon, Clarity...and much quieter transformers than found in one of the major American competitors. Zero hum or buzz can be heard through my speakers at idle, only the slightest hiss with ears against the tweeters.

My DAC is an LM model and also built like a BSH - again, very high quality parts throughout, no corner cutting. 

I have a Triode TRV 845 stereo amp.   Triode equipment is made by LM to Triode design specifications.   While not a LM branded amp I can say that build quality is outstanding.   Reliability has been excellent.  Bias has held rock steady for 2yrs.     You will be happy with a LM amp.  

Now, after a little more than 50 hours burning in, I’ve given the LM34IA a serious listening and I’ve made a comparison with my old Tube Technlogy Unisis Signature with EL84 tubes.
Differences are; 
Treble: TT more extended and more open than LM.
Mids: LM warmer and nicer than TT
Bass: TT tighter and cleaner than LM. LM sounds boomy and too much. But I know the room has a problimatic frequency around 46-48Hz and maybe LM manage to emphasis this. 

I think it sounds very good for the money, but I really need to get rid of this boominess (is there such a word?).
Anyone who knows which brand the stock tubes are and have a suggestion of some tubes that are thighter in the bass?

@simna

I recommend you to audition LM508 or 805

It will blow away any tube integrated amplifier under 9K.

One more tip is that if you change input tubes with some NOS tube, it will improve sound drastically.

You do not need to spend lot of money.

I got good result with NOS tube with 70$ pair.