@tweak1, @rc22 Thanks for the suggestions. In fact, I also read in the manual that a better power cable is recommended. I replaced the supplied PC of the Voyager GaN 350 with Audience Forte f3 PC. perhaps, there is some improvement in power and in base (I have to return the other cable and audition the amp again to be completely sure). But the most important thing that needs improvement remains a little dryness and lifeless in sound. Hopefully, this can be improved with break-in.
So far, my analytical thinking tells me that this is a very good amp. Pre-consciously, i am not still too attracted to the amp, all is good, but something (the soul) is still missing. May be i need to spend more time with the amp and this might be changed. For the final verdict, I will wait until it is fully broken in and then will try it in my main system (with better cables, transport, dac, acoustics, etc). This weekend I used it more than i usually do, it should already have close to 15 hours (in some amps, i was observing an improvement already after 10 hours). As to the other interconnect cables, honestly, i don't understand how a transport interconnect cable may influence on the performance of the amp (it may improve how the transport sounds of course). I have never tried spring pods but will bear this possibility in mind.
Later this week i may try the amp's balanced inputs with W4S STP 2 preamp.