depends on the topology.There are three tube types listed for this amp and I can not for the life og me see how there is a need for more than a single or at best one dual triode as the gain stage/driver stage since this amp is a single ended design and has no need of a phase splitter.
Unless it is an SRPP or MU-stage or the 12AU7 is used as a regulator OR the headphone amp is the 12AX7/EL84 pair and the preamp output the 12AU7.
Typical of Asian amps they love to tout what tubes are inside and push certain points but details are in very short supply and so come down to an educated guess unless you have the unit right in front of you .
I also find it humorous that the asian sites can not wait to reverse engineer everything Euro/US by doing close up photo shoots of every single part and every single angle with particular attention payed to cicuit board traces yet when the products originate locally NOTHING !
They have no problem with copying the work of offshore companies but protect their own rabidly.
anyway.............................
First,this is one of the most common sense layouts i have seen.total separation and shielding of the power supply without going to a two chassis design although if that power supply trafos runs hot the output trafos directly above on what would become a metal heat sink is a bit troubling (not to mention I HATE
toroids for anything but high current power amps)
The idea is a good one once I can get my head around the three tubes per channel,the design/layout about as good looking as it gets though maybe a slightly larger footprint than some would like until you consider it is also a
speaker amp AND has a self contained preamp which means add a source and play on !
The price is one I could not build the chassis for and the tube rolling potential unlimitied since these tubes are not only still being made but there are MANY NOS options out there which says you can pretty much voice the amp to taste,a real strength of tube gear that opamp rollers have only the tip of.
I am not one to recommend something I have never heard but I have to say i find the amp interesting though would be more comfortable knowing the topology-means everything
Oh yeah,2 watts per channel for speakers.
First of all it comes down to the speaker sensitivity in combination with where you listen and what type of music you prefer.Contrary to popular belief it is not rock music you need worry about when considering amp power but the symphonic or even (**gasp***) piano which will stress more systems than any other instrument short of a pipe organ/cannon shots.
Popular music has almost no dynamic range so no peaks and valley demands on the amp.Classical goes from leaning forward to hear to rocked back in your chair loud and THIS is the amp breaker !
This is what separates the pretenders from the contenders and if there is anything worse sounding than a clipping amp I don't know of it (other than a cat fight or a nagging wife
).
Use a low powered amp in a big room with a low efficiency full range loudspeaker then sit ten feet away and you will be dissapointed in the extreme.
take that same amp but mated to speakers it is more suited to drive,that is high efficiency speakers with limited bass (we expect too much from a speaker) then sit close as you would at the computer,called "nearfield" listening (see paper at the Tannoy site) and you would or should have all the volume you will ever need.
My current computer susyem is an old Dynaco PAS-2 with a few mods into a 1.2 watt per channel "Darling" amp (1626 SET) driving 5" full range speakers and i have no pressing need to make any changes.
My main system on the other hand is only 8 watts and even though the speakers are 96dB/1W/1M efficient being a multidriver set with a crossover I am underpowered and need to make a change.
I HATE this because I like the sonics of SET amps but the power you can get from a 300B in SET is at best 10 watts and any higher powered SET amps are friggin MONSTERS that have to go to either the 845,the 211 or the GM70 so it looks like PP Triode is in my future.both options $$$$$$$$
So i guess what i am saying is the EL84 single ended is fine at the computer listening close or with headphones but don't expect room filling volume levels while playing dynamic music or you will be severely dissapointed
Rickeraptor