Directly heated triodes, penthodes, ECC83 and 6J7 HE and SET world advise pls

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King_Julian_S

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Hi all.

Last night I stumbled on to something very interesting here.
I would like advise , suggestions and help please to try explain to me some of this.

As you may know ,,,, I use a prototype MARS 2a3 SET AMP.
This amp has two rca in directly to power amp and then it has a little pre section with two RCA's in so I can basically use it as an integrated or as a power amp only. 
The pre amp uses a 6J7 penthode type valve.
I use a valve CD Player and it uses the ECC83/12AX7 which is a dual triode.
The speakers are in the upper 90 sensitivity.

when using the power amp directly with source CD player I get the exact sound I am after.....in this scenario I use the CD volume control as there is no pre-amp in the chain so the gain stage I would assume is done via this triode ECC83 valves.... just the max SPL is extremely low... like an average person talking(not shouting,,,talking)...

when using the same as above but as an integrated amp so with source CD player into the preamp section of the 2a3 I get a grt sound but not as grt as the above. the SPL is satisfactory, will not even go close to max on this scenario. 

So as you can see above in the one scenario I like how the 2A3 plays the music(actually it much more then that,, but ...). however the SPL is low.
In the other scenario I still like how the 2a3 plays the music, but I would rather listen to the low SPL scenario as that is really so much better in playing the music.

So doing some reading about things I hardly understand, there is this stories around a bout using of penthodes in SET AMP circuits and dual triodes and DHT's etc.. etc... and like everything in hifi , different views.

Now to get to the point.
I have a gut feeling(cannot qualify this scientifically that's where u come in...) that using the ECC83 gain stage/preamp sounds different from the 6J7 as that is triode(dual) vs penthode and my preference is for the ECC83. however it creates the very low SPL issue... and I am assuming that it is merely because the CD players volume was not created for so much gain as a pre amp should have etc...

So I am asking if I change or use ECC83 in my 2a3 AMP for the pre amp side, will I still have a much lower gain then the 6J7 and will it mean lotso expensive changes to the pre amp to do this ?
I am hoping to get the sound I am getting in scenario 1 above , but with same SPL max level as per scenario 2 above.

Remember if I get this right and it works as per my gut feel, then I would need more inputs to the pre-amp also(like tape loops, tuner and even phono stage) cause I would then move the entire system to the 2A3 one time.

or what do you guys think  ? can it be the triode vs penthode that makes such a huge diff in sound ? can ECC83 be used with similar gain levels implemented as per the 6J7.... ?
If this kinda gain cannot be achieved by a triode type implementation then I think the alternative is to go to far more sensitive speakers and only Horns will more than 100db as far as I know(but I would not be able to afford real big horns....). 
 
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