is "floating phase" system having proper safety gnd potential ?
I resume not ..... it's more likely "nulled" ( which is term for tying neutral and safety gnd in home electrical installation) ?
if that is the case ...... that's just dummy safety gnd , having some safety virtues but certainly not working as proper drain of mains related nuisances
I resume not ..... it's more likely "nulled" ( which is term for tying neutral and safety gnd in home electrical installation) ?
if that is the case ...... that's just dummy safety gnd , having some safety virtues but certainly not working as proper drain of mains related nuisances
Zen:
They say it should be safe.......
The earth is floating between the two phases. When the difference in the 230 V system is more than 12 V in both directions / more than 127 V on one phase to earth, then it is a earth-error in the system who need to be fixed (fig 2)
They say it should be safe.......
The earth is floating between the two phases. When the difference in the 230 V system is more than 12 V in both directions / more than 127 V on one phase to earth, then it is a earth-error in the system who need to be fixed (fig 2)
Do we know how signal ground is connected to chassis ground in the XA30.5?
ZM, check your schematic. 😉
ZM, check your schematic. 😉
NTC
which schematic , MR ?
I don't have any
I'm one of rare Greedy Boyz not behaving badly , at PL SM underground
which schematic , MR ?
I don't have any
I'm one of rare Greedy Boyz not behaving badly , at PL SM underground
It is also some noise from other amplifiers. It could be something with my electrical supply to my house. Well, more investigations.....
did we established - is it hiss , or sort of buzz ?
hiss is , someone already wrote , as upper part of noise from FM tuner between two stations
buzz is much lower - and considering that PL factory amps are in question , gnd issues are out of question ..... but some mains related dirt is possible .......
is that single phase power grid , or multi-phase ?
if later , did you tried other phases , for amp(s) feed ?
hiss is , someone already wrote , as upper part of noise from FM tuner between two stations
buzz is much lower - and considering that PL factory amps are in question , gnd issues are out of question ..... but some mains related dirt is possible .......
is that single phase power grid , or multi-phase ?
if later , did you tried other phases , for amp(s) feed ?
aha , I found it
did you hear same buzz , mechanical , from amp cases ?
disconnect speakers for that
maybe you need DC blocker ........
In the tweeter horn it is hiss. In midrange it is hiss and a little buzz. I can hear it from my listening chair 230 cm away.
I am not sure if i understand your Q but i Norway we have 230 volt with two phase (L & N) and floating earth.
I am not sure if i understand your Q but i Norway we have 230 volt with two phase (L & N) and floating earth.
regarding AC from wall , that's same everywhere - if anything else , having pure AC is a dream
often there is also some DC , riding all around AC , mostly residue from modern switching appliances , refrigerators etc.
if that's the case , toroid trannies will sweat much more then old EI ones .... most probably passing through at least some of that trouble to secondary side
there is no other way to test that then either try to observe mains with scope , measure with DVM ( set to DC) or simply making quick and simple DC blocker (DC block filter) and try with it ( you can make it as mock-up , on wood or plastic platform , as part of short extension cord ; be careful - mains voltage ! ........ if it helps ........ make nice box , with several of these , each feeding one precious apparatus )
look at pic
often there is also some DC , riding all around AC , mostly residue from modern switching appliances , refrigerators etc.
if that's the case , toroid trannies will sweat much more then old EI ones .... most probably passing through at least some of that trouble to secondary side
there is no other way to test that then either try to observe mains with scope , measure with DVM ( set to DC) or simply making quick and simple DC blocker (DC block filter) and try with it ( you can make it as mock-up , on wood or plastic platform , as part of short extension cord ; be careful - mains voltage ! ........ if it helps ........ make nice box , with several of these , each feeding one precious apparatus )
look at pic
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superlian, I have a similar setup, just not as pretty. 😉
I had a buzz and a hum. Tried cheater plugs one at a time. Made a small different in lowering the noise, but it also affected the sound some how. It was dry. Best I can describe.
System had an interconnect that was not shielded from XO to bass amp. Installed a shielded ICs on XO to bass amp and the noise was almost all but gone in the full range amps, but not the bass amp. The hum is a bit lower in the bass amp. Almost tolerable, but still wish it were gone.
Have you tried different ICs? Just a thought.
Vince
I had a buzz and a hum. Tried cheater plugs one at a time. Made a small different in lowering the noise, but it also affected the sound some how. It was dry. Best I can describe.
System had an interconnect that was not shielded from XO to bass amp. Installed a shielded ICs on XO to bass amp and the noise was almost all but gone in the full range amps, but not the bass amp. The hum is a bit lower in the bass amp. Almost tolerable, but still wish it were gone.
Have you tried different ICs? Just a thought.
Vince
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Here's the spectrum of that noise from the midrange section:
Makes sense if your line frequency is 50 Hz in Norway.
What's interesting is that it is barely audible from the woofer section, which I would expect to be strongest around 100 Hz.
I'm doubting any of this is amp related.
Also, based on the clip with the microphone close to the speakers, it doesn't seem terribly bad really, but worth continued experimentation if only for fun and education.
A lovely setup, by the way. 🙂
Edit: Do you know the frequency response of your microphone? Just wondering if that's why I can't hear the woofer section.
Makes sense if your line frequency is 50 Hz in Norway.
What's interesting is that it is barely audible from the woofer section, which I would expect to be strongest around 100 Hz.
I'm doubting any of this is amp related.
Also, based on the clip with the microphone close to the speakers, it doesn't seem terribly bad really, but worth continued experimentation if only for fun and education.
A lovely setup, by the way. 🙂
Edit: Do you know the frequency response of your microphone? Just wondering if that's why I can't hear the woofer section.
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I made a video with ipad. I think the noise here is easy to analyze:
https://www.youtube.com/watch?v=7d4AgwQkC5A
https://www.youtube.com/watch?v=7d4AgwQkC5A
Yes. 🙂
It looks like the iPad microphone is down 12 dB at 100 Hz. Would you say the buzz coming from the woofer section is louder than the midrange section? Would you say twice as loud?
It looks like the iPad microphone is down 12 dB at 100 Hz. Would you say the buzz coming from the woofer section is louder than the midrange section? Would you say twice as loud?
So, let's say you're getting 54dB from .1 meters away from one speaker, that's 32dB from two speakers at your listening chair, which is just above a whisper as you described. 32dB at your listening chair from 95dB speakers requires about a microwatt from each channel, which would take a couple of millivolts of noise to produce, which more closely matches your description of being tube amp-like. So whatever ground loop or other line related phenomenon is present, it is certainly above the intrinsic noise of the amps themselves. Which just means it's probably worth tracking down.
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Wow, you searched after me on YouTube 😉
But i dont understand, your post is ca 5 minutes earlier than the upload conformation from YouTube?
But i dont understand, your post is ca 5 minutes earlier than the upload conformation from YouTube?
I have spies 🙂
Actually, I got a notification that you subscribed to my channel. Thank you, BTW.
Actually, I got a notification that you subscribed to my channel. Thank you, BTW.
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