Jolida JD100 noise issues

Through my experiments I found that the Jolida seems to give off a lot of noise. To explain further I usually do noise floor test by putting my amp full blast with nothing playing to here the noise floor. I found a rough sounding hiss. So what I did is turn off the Jolida and did the same thing and found the hiss was gone. Then I turned on the the Jolida (turning the volume always to 0 before any changes) and found the hiss wasn't there. So I thought maybe it was gone. UNTIL I put a cd in it and once it read the cd the hiss was back. I've tried this with numerous cd's and also different tubes, same hiss. I was wondering if anyone else found this to be and is there any way to remedy this... Thanks JohnnyP.
Since the Jolida has a tube output stage, I would start with replacing the tubes - especially if you are still using the stock tubes. Contact some of the reputable tube dealers (such as Vintage Tube Services, Tube Depot or Upscale Audio, etc.) and get a replacement pair that has been tested for low noise/microphonics. Based on my experience with the Jolida (as well as many others - check the archives), I would suggest trying a pair of 5751's as opposed to the 12AX7's. I was using some GE Jan 5751's that sounded great and were relatively inexpensive.
I owned a JD100 for a short time and didn't notice so much a 'hiss' as what I thought may have been the sound of the transport spinning the discs? It was constantly there while playing the disc, so I assumed it just utilized a noisy transport. I had this in a small 9x11 room where I was only 7' from the player and it was a distraction.
Hearing a little tube hiss when you are standing with your ear next to the tweeter with the volume wide open is not unusual for most all tube electronics. What would disturbe me a bit would be if you could hear the hiss at normal listening levels from your chair, or if you think it matters, with your ear at the tweeter. You are probably just hearing the CDP's noise floor, not noisy tubes. I have three tubed CDP/DAC's all of which have quiet tubes and all of which have an audible noise floor at max volume. FWIW
Let me start by saying thanks for the quick responses. Since this is my first endeavor with tubes it may just come down to tube noise. What confuses me is when the noise appears. The unit could be on and be fine but once a disc enters the unit and it finishes reading, the noise appears. I thought maybe the transport or the led display may be giving off noise. If it was tube noise wouldn't it be constant once the unit was turned on or is the unit just activated when a cd is read? I've tried 4 sets of tubes and all the same thing. Thanks for your answers, JohnnyP.
Well, I'm willing to take a guess - just from your description, I'm not a techie - the analog output section is muted while the disc is being read to prevent signals caused in the reading process to be transmitted to your preamp. That is what happens when you hit a mute switch on a pre-amp. The muting takes place after the amplifying stage so no signal goes to the amp. Works for me. :-)