how to optimize this pentode PP (PP1 clone with S11E12)

[Jaap]

I tried a pentode version of the PP1 amp with local (partial) feedback and a regulated screen supply.

I first used 100K between the plates of the 6H23 (= ecc88) and the EL34 or in my case the S11E12 (tried both). This sounded as too much feedback if you know what I mean (dead sound). After that I placed a 330K in series with the 100K but now the sound is too boomy (if that is a correct English word), I mean too much bass (unk, unk) which is tiresome after a while.

I suppose I have to choose a resistor in between 100K and 430K but what is optimal ? Another possibility is connecting the nodes between the 100K and 430K (or other values) with a resistor of 22K or whatever value is best. This is the solution "a la Baby Huey".
Or perhaps something else can be done ? I hesitated with global feedback till now.

[Jaap]

PSU:

[SY]

We've had some discussions recently about using the secondary to provide feedback to the output tube cathodes. If it's centertapped (i.e., there's 16, 8, 4, and 0 taps), I'd think about going that route.

[bigwill]

How about shunt feedback a la RH84 / RH807

Edit: Oh wait that's what you have Misread the schematic and thought I saw the feedback coming from the secondary