Just for an update, I've removed the first gain stage, the entire negative feedback circuit, and the recommended cathode capacitor from the 6922 for huge increased 3D soundstage and palpability. There doesn't seem to be a noticeable loss in extension or in bass drive, but even more micro dynamics and detail across the board and more natural sounding bass drive and dynamics.
So, that solves the gain problem regarding hiss from the preamp, I now turn the dial past 9 o'clock for adequate volume, infact if listening to digital media I can crank it without additional noise now,
Regarding hum, it was always very slight, and this mod has only brought it up a bit, my fridge is still louder... But I had been doing some reading on my time off and it sounds like some tweaking to the cathode resistors may work to solve that.
Any advise on adding local feedback circuits? ie; around 300b and 805, and one perhaps around the cascade/input???
Thanks for all your help so far.
So, that solves the gain problem regarding hiss from the preamp, I now turn the dial past 9 o'clock for adequate volume, infact if listening to digital media I can crank it without additional noise now,
Regarding hum, it was always very slight, and this mod has only brought it up a bit, my fridge is still louder... But I had been doing some reading on my time off and it sounds like some tweaking to the cathode resistors may work to solve that.
Any advise on adding local feedback circuits? ie; around 300b and 805, and one perhaps around the cascade/input???
Thanks for all your help so far.