A few nanowatts of noise through 95dB speakers at 2-3 meters should be barely audible to a young person with good ears and practically undetectable to a geezer like me. Would you describe the noise as low humming, buzzing (sort of like a florescent light), or hiss (like a radio tuned to static)? And, how far away do you have to stand to no longer hear it?
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Noise (hum) or hiss
I'm still not sure if OP meant noise or hiss.
As Nelson wrote noise or hiss with nothing connected is almost never the case.
If hisssssss is the problem, then.... well I have the same problem.
As soon as I connect my XP10 to the XA30.5 I hear significant hisssssss from my speakers. The speakers are 96dB sensitive with horn midrange and ultra tweeter.
XA30.5 only with nothing connected to the front end is quiet!
Same problem with XA100.5.
I think I've to live with it.
I'm still not sure if OP meant noise or hiss.
As Nelson wrote noise or hiss with nothing connected is almost never the case.
If hisssssss is the problem, then.... well I have the same problem.
As soon as I connect my XP10 to the XA30.5 I hear significant hisssssss from my speakers. The speakers are 96dB sensitive with horn midrange and ultra tweeter.
XA30.5 only with nothing connected to the front end is quiet!
Same problem with XA100.5.
I think I've to live with it.
If you hear the noise with no inputs connected to the power amps, then that
is highly unusual, unprecedented even. Are you sure this is the case?
Yes, but as i wrote, it isnt that bad (and not like a ground loop) but still it is there. Maybee this is HiFi-Paranoia
I will ask some of my very experinced HiFi buddies to evaluate it.
THX for helping so far
2,3 meter listening distance, like a Valve-amp. I am 45 and i have not gold-ears. Its Buzz in the meaning not low not high. Just ordinary Buzz like low signal/noise ratio.
I think from 5 meter, i cant hear any Buzz but let me check again. I will also let my 17 year old son check.
If I follow correctly, your description suggests something more than just intrinsic noise. I think it would be worthwhile to continue experimenting. First, try connecting only one amp to the speakers with the other completely disconnected from signal and power. Be quite certain that no signal cables are connected, and power everything else off just for good measure. Let us know if the noise is louder than a faint whisper at your 2.3 meter listening distance.
"Just because you're paranoid doesn't mean they're not after you."
"Just because you're paranoid doesn't mean they're not after you."
Yes, all other components are disconnected from both signal and power. And the noise is a bit more than "a faint whisper" when the amp is free.
My initial thought is that the XA30.5 have a noise level like many tube amps.
But......more investigation is on the schedule
Lian,
Have you noticed if the noise increases or decreases at certain times of the day?
Also, are the amps plugged directly into the mains or are they plugged into a power strip?
Finally, when testing, assuming you have the ground jumpers in the XLR connectors, have you tested with a shorting plugs in the RCA jacks?
Have you noticed if the noise increases or decreases at certain times of the day?
Also, are the amps plugged directly into the mains or are they plugged into a power strip?
Finally, when testing, assuming you have the ground jumpers in the XLR connectors, have you tested with a shorting plugs in the RCA jacks?
No, and i dont use a powerstrip. I have a lot of wall outlets.
It is ground jumpers is in the XLR yes. I haven't tested shorting plugs.
I think i am a little bit closer now.
1) my listening distance is close, ca 2,3 m
2) the room is 3,3 x 5,15 m and medium damped
3) the speakers sensitivity is 95 dB
I cant be too demanding, it will be some noise
Today i was at a friends place. I listened to the noise from his Aleph J via Autotech horn and JBL 2446. The connection was free of crossover components since he runs active x over. His noise level is ca equal with mine. But his sensitivity is 110 dB.
I also tested a Sonos ZP100 at my place now and the noise is ca the same, maybe a tiny bit more from XA30.5. In additon to the "sshhhhhhh" XA30.5 have a slightly trafo-hum from the midrange which Sonos doesnt have.
1) my listening distance is close, ca 2,3 m
2) the room is 3,3 x 5,15 m and medium damped
3) the speakers sensitivity is 95 dB
I cant be too demanding, it will be some noise
Today i was at a friends place. I listened to the noise from his Aleph J via Autotech horn and JBL 2446. The connection was free of crossover components since he runs active x over. His noise level is ca equal with mine. But his sensitivity is 110 dB.
I also tested a Sonos ZP100 at my place now and the noise is ca the same, maybe a tiny bit more from XA30.5. In additon to the "sshhhhhhh" XA30.5 have a slightly trafo-hum from the midrange which Sonos doesnt have.
I have a similar setup and am having a noise issue as well. I believe mine to be ground issue related to active x0ver. I'm running open baffle setup with x250.5 for the low xa30.5 for the high using a b5 crossover. I get a slight hum from the x250.5 at listening position and nothing audible from the xa30.5, for the most part I believe this to be normal operation. What's not normal is I get a sound best described as hearing the wind outside on a blustery night coming through the woofers only. After a bunch of investigating I stumbled on something, I have the top of the b5 off and if I touch the output wires to the low pass RCA's it creates the sound, if I push the wires to a different position the noise will stop. I'm at a bit of a loss to whats up. Again no problem on the high pass side and no audible noise from the xa30.5 with 94db efficient speakers. This leads me to believe you shouldnt be hearing your noise. I myself am going to try the cheater ground to see if that's causing my problem.
My B4 is not providing any extra noise.
I will check furter ground loop issues.
In Norway we have "floating phase" 230 V electrical power. It is only Norway and Albania who still have that "vintage" system. It causes often trouble and one thing i can try is to simply rotate the power cable plug!!
The Norwegian designer (Leif Ernstsen) of Dynamic Precision amplifiers* have a special method to reduce the Norvegian phase problems. I could maybee also try a separating transformer og a power cleaner like PS-Audio (expensive).
* who they use in f ex Abbey Road studios, 2L also use D.P.
One Q: is it dangerous to connect only one amp like i do now without ground? or will ground loops only be there with two or more components?
I will check furter ground loop issues.
In Norway we have "floating phase" 230 V electrical power. It is only Norway and Albania who still have that "vintage" system. It causes often trouble and one thing i can try is to simply rotate the power cable plug!!
The Norwegian designer (Leif Ernstsen) of Dynamic Precision amplifiers* have a special method to reduce the Norvegian phase problems. I could maybee also try a separating transformer og a power cleaner like PS-Audio (expensive).
* who they use in f ex Abbey Road studios, 2L also use D.P.
One Q: is it dangerous to connect only one amp like i do now without ground? or will ground loops only be there with two or more components?
The ground prong on your power cord connects your amplifier's chassis to earth ground, which is required for your safety in case your chassis accidentally becomes energized. It should not be defeated unless the chassis is connected to earth via some path.
If you are doing the single amplifier noise test described earlier with a defeated ground connection, stop and plug it in correctly.
If you are doing the single amplifier noise test described earlier with a defeated ground connection, stop and plug it in correctly.
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