Sorry to say, that still shouldn’t matter.
Low level HUM, driving me CRAZY!
- Thread starter marpow
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I would tend to agree with Perp......I've had B&W speakers for years [802 Nautilus] and I NEVER felt a need to bi~wire them and my systems were always DEAD QUIET and before I recently 'tore apart' my man cave to 'prepare' for my new system, I was running over 35' of balanced XLR Transparent cable from my Meridian pre/pro to my Krell 650 Mc MONO amps.
Sorry I suggested you ground your system as I didn't realize it was already grounded when the house was built. My house is much older and when I did ground it, the noise level WAS ZERO.
BTW, when your heating/AC system kicks in, did you ever experience extraneous noise through your speakers?
Telling you try the ipurifier. I also was bugged by a similar hum and tried everything, my system is now dead silent. These can be magic. Order from Amazon if it doesn’t work return it.
No extra noise ever when anything kicks in.
When you did not Bi Wire did you use jumpers?
I am under the impression you at least have to use jumpers? Yes/No?
Sounds like maybe @Perpendicular is on to something; and maybe you've already partially localized the problem no?
I tried my B&W speakers from downstairs and was worse even though they make zero hum downstairs, now going to try one of my Definitive towers that is in garage.
OK, but are you also wiring them the same way?
Process of elimination. Good.
I would now try to hook up one amp at a time to one and then a pair of speakers.
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NO jumpers, Markie.
jimfisheye
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Separate amplifiers but it's in everything?
What happens when you only power up one amp at a time?
ie. Will one power on by itself hum free?
It is still there with inputs disconnected? (Sorry if already answered.)
What happens when you only power up one amp at a time?
ie. Will one power on by itself hum free?
It is still there with inputs disconnected? (Sorry if already answered.)
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I would DISPENSE with the bi~wiring and the jumper cables and simply engage a single speaker pair from the main amps to the speakers. Simplicity, Simplicity
I'm confused. I thought if a speaker had 4 terminals on rear that you needed to either jump or Bi?
If as you say you only go single speaker cable do you plug in for lack of a better term to the lower Bass Terminals or the top midrange terminals?
To be honest I am not sure what you say makes sense, But I will at least give it a try and see what it sounds like.
From what you have said it sounds to me like you have a problem with your preprocessor. When you have the hum humming away, wired how you like it, switch off the pre pro. I predict the hum will disappear. Leave the power amps on.
If that is the case then you have to determine whether the problem is a ground loop or an internal malfunction in the preprocessor such as a defective filter capacitor. The first thing I would do , not worrying about speaker connections , would be to run a pair of fairly heavy gauge (12-16gauge Spikker cable will work great!) strands of wire (traditionally green or in Europe green and yellow) between the chasis s of your pre pro and your power amps. PrePros often have a ground terminal like preamps used to. You might need to smash the wire on to a spot of bare metal somewhere because aluminum anodizing is not a good conductor. Also make changes one at a time. You could also have a phase inversion somewhere which is causing hum. If all the permutations of connections between amps and prepro don't eliminate the hum, try a different pre pro(or simpler preamp). Or see whether you have hum in the headphone jack of the pre pro (if it has one available)
I generally do not recommend power conditioners, but if it is a problematic ground loop, a conditioner that has in it an isolation transfomer can block ground loops. But if you have a bad filter cap in the power supply none of these solutions will do anything. Then it needs to go onto the service bench.
If you decide to try a power conditioner get a real one from Sola or TrippLite , not one from a hifi source.
Another question to look at is the number of connections in the power cable. I was surprised that my Marantz AV 7005 pre pro has a two conductor IEC cable with no ground. Older stereo gear (which I have a lot of) also only has two connections. One thing about three conductor IEC cables such as are used on computers , is that they make the connection referred to above for you all the ground pins being connected together at the outlet strip.
If that is the case then you have to determine whether the problem is a ground loop or an internal malfunction in the preprocessor such as a defective filter capacitor. The first thing I would do , not worrying about speaker connections , would be to run a pair of fairly heavy gauge (12-16gauge Spikker cable will work great!) strands of wire (traditionally green or in Europe green and yellow) between the chasis s of your pre pro and your power amps. PrePros often have a ground terminal like preamps used to. You might need to smash the wire on to a spot of bare metal somewhere because aluminum anodizing is not a good conductor. Also make changes one at a time. You could also have a phase inversion somewhere which is causing hum. If all the permutations of connections between amps and prepro don't eliminate the hum, try a different pre pro(or simpler preamp). Or see whether you have hum in the headphone jack of the pre pro (if it has one available)
I generally do not recommend power conditioners, but if it is a problematic ground loop, a conditioner that has in it an isolation transfomer can block ground loops. But if you have a bad filter cap in the power supply none of these solutions will do anything. Then it needs to go onto the service bench.
If you decide to try a power conditioner get a real one from Sola or TrippLite , not one from a hifi source.
Another question to look at is the number of connections in the power cable. I was surprised that my Marantz AV 7005 pre pro has a two conductor IEC cable with no ground. Older stereo gear (which I have a lot of) also only has two connections. One thing about three conductor IEC cables such as are used on computers , is that they make the connection referred to above for you all the ground pins being connected together at the outlet strip.
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Tried that,
see my #6 post #1.
6. I was absolutely convinced it was my pre/pro to the point where I ordered a new updated version, willing to pay the restocking fee if no change, my heart sunk when there was no change.
see my #6 post #1.
6. I was absolutely convinced it was my pre/pro to the point where I ordered a new updated version, willing to pay the restocking fee if no change, my heart sunk when there was no change.
Does probing with a grounded length of spikkr cable between the pre and power amps do anything?
Are all the power cables three wire?
That swapping pre pros didn't fix it is almost good news since it means there is probably nothing wrong with the pre pro.
Does the hum ever come and go such as from some distant appliance turning on and off or cycling?
The fact that it changes when you go from xlr to rca reminds me that there are multiple conventions regarding the wiring of xlrs and they don't always match. I think there is a European and American convention wherein the + and- are different. You might look in the equipment manuals and see whether you are running afoul with that.
I hate noise in electronics. Hum is better than hiss because you can usually beat it to death. Hiss there is hardly anything you can do about.
Are all the power cables three wire?
That swapping pre pros didn't fix it is almost good news since it means there is probably nothing wrong with the pre pro.
Does the hum ever come and go such as from some distant appliance turning on and off or cycling?
The fact that it changes when you go from xlr to rca reminds me that there are multiple conventions regarding the wiring of xlrs and they don't always match. I think there is a European and American convention wherein the + and- are different. You might look in the equipment manuals and see whether you are running afoul with that.
I hate noise in electronics. Hum is better than hiss because you can usually beat it to death. Hiss there is hardly anything you can do about.
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You are correct. If using only one cable to the speaker you need to use the jumpers to connect the 2 pairs of terminals to each other. It doesn't matter which pair of terminals you connect the cable to.
If you turn off your subwoofer(s), does the humming stop? I had a ground loop hum a few years ago, and the way I finally fixed it was to run ground wires from my subs to my power conditioner.
Does probing with a grounded length of spikkr cable between the pre and power amps do anything?
Are all the power cables three wire? YES, Shunyata and AudioQuest, except the DVD, FireCube, DirecTV, Exasound has it's own power supply.
That swapping pre pros didn't fix it is almost good news since it means there is probably nothing wrong with the pre pro. Agreed.
Does the hum ever come and go such as from some distant appliance turning on and off or cycling? NO.
The fact that it changes when you go from xlr to rca reminds me that there are multiple conventions regarding the wiring of xlrs and they don't always match. I think there is a European and American convention wherein the + and- are different. You might look in the equipment manuals and see whether you are running afoul with that. Will do.
I hate noise in electronics. Hum is better than hiss because you can usually beat it to death. Hiss there is hardly anything you can do about.
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