Hi all.
In my EVOLUTION or quest to get better sound quality,
I've tried a few times to upgrade the sound quality of my Decware SE-84C+
I've tried differenc brands and models variation of power tubes
and voltage amplifier and even the rectifier tube.
For the power tube, the amplifier was supplied with Russian SV83,
then I tried the Electro Harmonic, then the Gold Lion EL84 and out
of the three brands, the EH EL84 sounded a little better,
just a little, maybe maximum 10% better sound quality mainly in the mid frequencies.
Difficult to judge the differences between the tubes,
since sound memory only last 1 second (For me) therefore,
shuting power, using mits not to burn my pinkies, pau back the new tubes,
power back the unit and wait to warm up,
the one sencond is more like 30 seconds at best.
I also tried a pair of Toshiba NOS EL-84 but they sounded terrible,
I am not exagerating, sound was like putting several layers of hand towels over the speakers
and the volume had to be jack up a lot, like 50% more,
I returned the tube and exchange them for the Gold Lion.
I also had two other tubes from the same supplier that were defective,
no need to say that he's on my black list.
No name will be mentionned here, I don't want to tarnish his reputation...
For the voltage amplifier tube, the 6922, I've tried many different brands:
No name Russian, Electro Harmonic Thomas organ tube, RCA NOS,
and aonther brand that I forgot the brand name.
Since I did not hear any differences between all the tubes,
I end-up keeping the Electro Harmonic 6922.
In the future, I might try the 6DJ8 according to Decware,
that tube got more micro details that the others.
Will see, not an expensive trial or maybe up-grade.
For the rectifier, lots of people say that the 5U4 improve the sound over the 5AR4,
didn't hear any difference, but kept the 5U4 in there.
So that all my foolling aroung with tube to try to improve sound quality
but in the end it was fun, but kept the RCA 5U4, EH EL84 and EH 6922.
Guy 13