Well, got my BL8000s installed yesterday and all my other B&O stuff mounted properly. WHAT A DIFFERENCE!!! All connected to my Onkyo TX-SR875 with 8000's as front L/R channel and BL4's as rear L/R.

My issue is this...At bedtime I turned my Sky HD off then turned off the Onkyo. Pottered about a bit for and went back into living room. 8000's still powered up (green light on) and giving off a low hum. Must have left them for a good 20 mins

Switched the Onkyo back on and must have inadvertently pressed the DVD button on the remote and the speakers almost instantly powered down. Then pressed the 'standby' button on the Onkyo to switch it off again and low and behold the 8000's powered back up!!!

I thought the 8000's powered down when no input is received? I'm at a loss as to explain WHY the speakers would power back UP from a powered DOWN state when I switch the receiver OFF?????

Anyone???

Scott

How long do they stay up?

p.

Well, I left them for a 'good' 20mins and they still had the green light on. Its strange that as soon as I switch to a piece of equipment that is off (in this case my DVD player) they powered down within 5s.

It would appear that they are getting some sort of signal from the receiver but thats impossible as its switched off (not standby but proper off).

 

Odd....

Seems like some part of you setup gives a signal to the Onkyo, and the Onkyo loops it trough even though it's shut off.

 

I would try and isolate what part it is, power up/down with only one source connected to the Onkyo. Maybe it's the Onkyo itself. 

When you connect it to the DVD player, there is no output - complete silence.

If you turn the amp off, you say you hear a quiet hum from the speakers.  This implies that when the amp is switched off, the outputs become disconnected from any active circuitry (such as the DVD player tying the signal to ground), and it's picking up any old random interference - probably mains hum at 50Hz.

 If I change my speakers to line mode with nothing connected, they hum and never shut down.  I would suspect it's this.  Unfortunately, I've not got many suggestions to fix it!

csmager:

 If I change my speakers to line mode with nothing connected, they hum and never shut down.  I would suspect it's this. 

Sounds exactly the same. Are there any products which can reduce the mains hum i.e chokes or some power supply filter?

I have some cylindrical chokes I might slip over the mains lead just to try out.

 

Scott

tarmacterror:

Sounds exactly the same. Are there any products which can reduce the mains hum i.e chokes or some power supply filter?

I have some cylindrical chokes I might slip over the mains lead just to try out.

This wouldn't probably help at all because the mains lead is not where the hum comes from. If the theory by csmager holds, then it's the signal leads - they work as antennae and pick up the hum literally "from the air" when they are effectively disconnected. If you talk about ferrite chokes, they won't do much of anything at the 50 Hz area anyway, they are designed to filter RF noise.

I would probably try some 10 kohm resistors in parallel with outputs from the amp to keep it from becoming very high impedance. This should keep the hum level low enough to not be mistaken for a signal when the amp is off... but I can't say in advance if it really would work.

the ~10k resistors would definitely be something I'd try - it should be high enough so as to not affect any signal, but low enough to hopefully cut out the noise when it's off.  Worth a go!