Originally Posted by gibosi
While this is true for all-tube amps, where driver tubes actually "drive" the output tubes, in the LD 1+, the driver tubes don't really "drive" anything. And in fact, if one wanted, the tube stage can be bypassed by a straight wire, and the amp would still work perfectly fine, minus the tube "flavor". With no interaction between the tube and op amp stages, the op amp simply amplifies the audio signal after it has been "flavored" by the tube. And therefore, I am quite confident in saying that the C3g is inherently a bit more forward than my reference Sylvania, all else being equal.
But of course, as those of you who have power tubes know, finding and selecting driver and power tubes with just the right synergy is half the fun. And I do hope to be able to eventually find and purchase an OTL amp with 6AS7 type power tubes so that I can double my fun too. :)
Yes indeed, having a neutral power stage - for comparisons at least - seems very useful for assessing different drivers...and interesting that you and mab find a forward signature for the C3g, which I only found with the Sylvania VT231.
ALSO FOR ANYONE interested in different power tubes....
On the subject of synergy - plus TDs reiteration of matched tubes not being necessary in our LDs - I have just completed my first adapter for the Tung Sol 7N7 as powers(Sylvania chrome-top), after having foolishly(?) assumed that being a loctal-version 6SN7 the pin-out would be the same!... and double SHOCK/SURPRISE/BEWILDERMENT...then JOY...
Firstly, after resin getting where it shouldn't!, it actually worked...
Secondly, even before adapter burn-in, I could not believe my ears...something that doesn't seem to have worked well for folks before now...with the 7N7 in the right channel and the Psvane in the left - absolute MAGIC! NOS American plus young(ish) Chinese? - NO WAY is what I was expecting...certainly not what (at the moment anyway) appears to be a very happy marriage of the best of the Psvane and that of the VT231...the spatial clarity of the former, with a bit more of the mids and bass of the Sylvania/Tung Sol.
Obviously I need to see if this holds for my other test pieces, but at the moment I am somewhat gobsmacked...so perhaps experimentation with 'mix and match' of power tubes is in fact a possible option after all!! What is there to lose, I ask?
So another step forward in the power tube saga - for me, anyway. Should be interesting to see what happens with the two 7N7s...but that will have to wait a wee while, I'm afraid...those adapters are a bit of a pig to make - I defy anyone to make one with a 22mm case!!...Of course, any sensible person just buys the ready-made 7N7 to 6SN7 adapters and piggy-backs onto the 6CG7 adapter...but TWO lots of degradation? - not for me!
Anyway, time to come back down to Earth and get on with the chores...will check later to see if I was simply hallucinating after too much strong coffee
Edited by hypnos1 - 4/18/14 at 6:48am