The setup:
I have a Stereo amplifier and an AVR, the stereo amplifier has a built in DAC.
CD player connected to stereo amp via RCA and to AVR via optical
Decoder connected to AVR via HDMI as is BDP.
TT not connected as there is no phono stage anywhere.
Raspberry Pi connected to the AVR via HDMI and to the DAC via USB (play music with Squeezelite to stereo amp and video with Kodi to AVR). R.Pi connected via wifi to router/network
The pre/power amps of the stereo amp has outputs/inputs typically connected with an RCA jumper plug, however, I have a simple selection switch to select between the pre-out of the AVR or the pre-out of the stereo amp to feed the power amp section, thus the AVR only drives the surround sound speakers, L&R driver by the stereo amp.
The problem:
I had the AVR and the Stereo amp positioned next to each other (side by side) and the Raspberry on a shelf below them. No problem whatsoever and sound quality was brilliant.
Got a new dedicated glass door hifi rack/shelf/kas whatever you call it.
Power amp on the top shelf (?10cm clearance to top)
AVR below on shelf below, ?7cm clearance to the shelf above.
Below that the CD player
Below that the Raspi and the decoder.
below that the BDP.
Now, when I connect the Raspberry Pi to the DAC with USB (fine on its own, if HDMI not connected to AVR) and the HDMI to the AVR (once again, fine on its own, when the USB cable is not connected) there is a very loud lowish frequency noise if the Raspi is not powered up. Once the Raspberry is powered up, it becomes a faint, but clearly audible high frequency noise. This is irrespective of wether the pre-amp of the AVR or the Stereo amp is selected and irrespective if the AVR is switched on or not.
The only two conditions to create this noise is that the stereo amp must be switched on and that the ASB and HDMI cables must be connected. if the raspberry is switched on or off only changes the type of noise.
Tried the following to no avail:
Changed the cables (USB and HDMI)
Changed the Raspberry
Removed the wifi dongle
What can be the cause? The only change that occurred is the positioning of the equipment. Further, I noticed that both the AVR and the stereo amp has the kettle type leads and plugs, but there is no connection on the power socket of both amps for earth, only L&N. same goes for everything in the system, nothing has a earth connection to the mains.
Any help, opinion or speculation will be appreciated.
Regards
Since it happens when the
I have a Stereo amplifier and an AVR, the stereo amplifier has a built in DAC.
CD player connected to stereo amp via RCA and to AVR via optical
Decoder connected to AVR via HDMI as is BDP.
TT not connected as there is no phono stage anywhere.
Raspberry Pi connected to the AVR via HDMI and to the DAC via USB (play music with Squeezelite to stereo amp and video with Kodi to AVR). R.Pi connected via wifi to router/network
The pre/power amps of the stereo amp has outputs/inputs typically connected with an RCA jumper plug, however, I have a simple selection switch to select between the pre-out of the AVR or the pre-out of the stereo amp to feed the power amp section, thus the AVR only drives the surround sound speakers, L&R driver by the stereo amp.
The problem:
I had the AVR and the Stereo amp positioned next to each other (side by side) and the Raspberry on a shelf below them. No problem whatsoever and sound quality was brilliant.
Got a new dedicated glass door hifi rack/shelf/kas whatever you call it.
Power amp on the top shelf (?10cm clearance to top)
AVR below on shelf below, ?7cm clearance to the shelf above.
Below that the CD player
Below that the Raspi and the decoder.
below that the BDP.
Now, when I connect the Raspberry Pi to the DAC with USB (fine on its own, if HDMI not connected to AVR) and the HDMI to the AVR (once again, fine on its own, when the USB cable is not connected) there is a very loud lowish frequency noise if the Raspi is not powered up. Once the Raspberry is powered up, it becomes a faint, but clearly audible high frequency noise. This is irrespective of wether the pre-amp of the AVR or the Stereo amp is selected and irrespective if the AVR is switched on or not.
The only two conditions to create this noise is that the stereo amp must be switched on and that the ASB and HDMI cables must be connected. if the raspberry is switched on or off only changes the type of noise.
Tried the following to no avail:
Changed the cables (USB and HDMI)
Changed the Raspberry
Removed the wifi dongle
What can be the cause? The only change that occurred is the positioning of the equipment. Further, I noticed that both the AVR and the stereo amp has the kettle type leads and plugs, but there is no connection on the power socket of both amps for earth, only L&N. same goes for everything in the system, nothing has a earth connection to the mains.
Any help, opinion or speculation will be appreciated.
Regards
Since it happens when the
