Here is some info about the differences in the ACT2.2 upgraded from the original:
- improved power-supply architecture;
- eight-fold increase in size and upgrade from polystyrene to Teflon for the capacitor by-passing the input filter;
- upgrading the remaining capacitors in the audio circuits from polystyrene to Teflon;
- improvements in grounding;
- added internal shiled results in a 5dB noise reduction.
Fwiw, I'm running the 'NOS' 6H30П-DRs - *maybe* they yield a faint increase in higher frequency extension. Now that the price has really jumped on these - purportedly the last stock available - I'm not sure there is a lot of payback for this tube roll in the ACT2.
I really wanna hear the new CJ TEA1 phonostage - anyone had a listen yet?
Cheers,
Tim