I love the BS on that web site. Someone must be making a career of spewing crap. Grab your hip boots, friends:
Signal current, no matter how well it is treated by the phono stage, must negotiate the inner workings of the power supply and return to its origin. Knowing that origin and how it gets...
I think there's confusion here.
Most of you took "70 dB" to mean the amount of isolation. That's what I thought the OP meant, too.
But now I think he means that he wants to block extraneous background noise so that a noise at 70 dB (would that be 70 dBA, or some other absolute scale?) should...
Regarding break-in ... I was a non-believer until last year. At that time I bought a Sennheiser HD579. I was REALLY unhappy with the sound.
I used them for a short while ... maybe 15 minutes.
The next day they sounded great. Like a completely different unit.
Maybe it just needed its "joints"...
I don't take much stock in instrumented measurements. Engineers need those. Listeners don't.
I don't. All I need is a pair of ears. No other measuring apparatus matters. Really.