MHDT Havana Questions

To all MHDT Havana owners out there - do you leave your DAC on 24/7 or turn it off after a listening session?

I just got mine, so it's not broken in yet. Has about 5hrs playing time on it and left it on over night.

Now, listening to it this morning, at the lowest volume level, of the duet (my transport is squeezebox > MHDT DAC via coaxial cbl) there is considerable noise level throughout the low volume levels. In between song fade out/in at the lowest levels the sound is distorted and compressed before it kicks in at the start. Take the Havana DAC out of the chain and no noise at low vol levels or the inter-song distortions. Changed the PC with no effect as well as direction of coax cbl. Haven't tried the optical digital out yet of the DAC.

Those with Havanas have you experienced this with yours? Wondering if the low vol harshness/noise will go away as it breaks in?