fantastic thread wyldrage..
you really ought to move to BJT outputs on the EHHA...much more involving than the MOSFET output devices.
Also for more midrange warmth try the Valvo 6GM8s. Upscale AUdio still has some stock of these.
Of course my go to choice is still the telefunkens of which i have a pair. Drop me a PM if you want to buy them.