High pitch tone from AlephMini

[yoke]

Hi
I have posted before that I'am working on 2.5way active loudspeakers. It takes me ages, but...

any way

The setup is
NAD S500 cd player
behringer DCX2496
NAD S170 (six channel preamp)
Aleph Mini to SS 2904/7000
Aleph30 to SS 18W8545

The thing is that I have high pitch tone on twitter driver. It's not that high in volume but it's there.(around 16kHZ or more) I can hear it when I place my ear near the driver (around 5cm (2 inch)).

The other thing is the cracking noise, you know the sound you get when you connect speakers on live, you get cracking while connecting it on amp...also on tweeter driver

O.K. this is the first time that I have been lisinng those amps for more than a few hours so it maid be just a burning in...but...

I'm more concerd about high tone pitch from AlephMini on 2904/700 bacause it's iritaiting ;-)
So does any one have some idea what could cose this ?

The Aleph30 (SS18W8545) is dead silent, no noise, no brum...

Thanks

 

[yoke]

I have been lesening this for a while.
It seams that thing get better ,as now I can't hear high pitch tone, only the small volume oh noise..and this cracking noise...but only when I place ear very close to driver...
will see how it will end