@taccodude
Are you using one SMPS for both channels?
Did you try to power 1 module and test?
Test both modules separately and report result.
The noise is always there, while the amplifier is ON? or only when shutting down the power?
The Noise from the Tweeter is always present ,you can hear it 5 Meters away .When shutdown is a different one.
taccodude do you have an oscilloscope to observe AC conditions on the rails and on the output of the amp? Is it HF hiss or 100 Hz transient peaks on tweeter present also with inputs shorted with wire? With linear PSU complete silence? Over the years I learned that I had less problem with SMPS than conventional PSU.
sorry no Oszilloscope, it sounds like cracklin when Welding ,if You know that(not that loud),
It is not totaly quiet now,but You have to be about 10cm away before you hear some Hiss.
It is not totaly quiet now,but You have to be about 10cm away before you hear some Hiss.
check your signal input I think bad connection
Taco, can you mail me to explain what exactly is wrong?
Taco, can you mail me to explain what exactly is wrong?
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Noise......
A noise from the amplifier when you shutdown the SMPS is 100% amplifier related, that's because the voltage will drop very quickly and the amplifier will get affected by that.
A continuous HF noise could be from anything, I would suggest that you test with different amplifier to spot out the problem.
* Also you didn't answer my previous questions..
Hope that helps.
A noise from the amplifier when you shutdown the SMPS is 100% amplifier related, that's because the voltage will drop very quickly and the amplifier will get affected by that.
A continuous HF noise could be from anything, I would suggest that you test with different amplifier to spot out the problem.
* Also you didn't answer my previous questions..
Hope that helps.
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Could the wiring making the connection between the psu and the amp be acting as an antenna? Not knowing what Taco is using for lead-in wires how about trying, if he hasn't, a pair of twisted lead wires or a shielded pair and see if this changes the level of noise?
Today I tested each Channel separat and moved SMPS in the Middle and than out of the box ,but it doesn`t matter.
Noise is alwas present.It gets more with DAC/Pre hooked up. Maybe I should put some tiny Wire on FO so that I can measure safe.Is that a good way to do it ?
Noise is alwas present.It gets more with DAC/Pre hooked up. Maybe I should put some tiny Wire on FO so that I can measure safe.Is that a good way to do it ?
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I would really like to get those two modules back to test if they'd be noisy here too, since that kind of noise conditions I can't reproduce even if I try hard.
LC,
Wouldn't you need to check with his actual power supply to see if that is where the problem really is coming from? He did make the comment that with a linear power supply the units were almost silent. I keep thinking some of this is the cabling he is using for connections.
Wouldn't you need to check with his actual power supply to see if that is where the problem really is coming from? He did make the comment that with a linear power supply the units were almost silent. I keep thinking some of this is the cabling he is using for connections.
Last Night I found the Problem ,I tried a lot and found out that FO with SMPS doesn`t like a Main Filter in Front. Every other Gear I got ,has no Problem with it,tried every Combination .Is that Normal ? I mean,I`m happy that I found it,but with the Filter in Front it sounds better ,even with that Noise.
taco,you always could use a pics nose at the power inlet and use a ferrite core at the DC output.
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Hi,
If my memory serves me well, I believe I read somewhere this SMPS should not be used with a mains filter. Sadly, quickly browsed through the docs and couldn't find it, but was very quick... Worth an eye perhaps?
What you can find though is that this SMPS "seems" to already incorporate mains filter, following to the block shematic found in its datasheet page 2. Perhaps you have 2 mains filters having odd effects against each other, although I perfectly understand it shouldn't really (unless silly values) if they are say purely passive... But then they aren't perhaps?
I also understand your set up sounds better with mains filter, despite the prob you described. I like good mains filters aswell. I wonder if that better sound is due to your additional mains filter being "really" in front of the SMPS / amp section. It sounds unlikely to me given the high frequencies of the SMPS. I mean, given many filters are both ways, is the better sound really coming from filtering IN, or rather to the fact you are filtering high frequencies OUT of the SMPS/amp and cleaning mains for other devices?
Would you better sound be identical by putting your filters in front of all the other music playing components and leave the amp alone? That could help you having the best of both worlds : better sound without the problem, although I understand it would involve quite a bit more mains filters but then if you have one you can play with you could, as a start try it in front of several music playing devices to find the most benefical location.
Good luck
Claude
If my memory serves me well, I believe I read somewhere this SMPS should not be used with a mains filter. Sadly, quickly browsed through the docs and couldn't find it, but was very quick... Worth an eye perhaps?
What you can find though is that this SMPS "seems" to already incorporate mains filter, following to the block shematic found in its datasheet page 2. Perhaps you have 2 mains filters having odd effects against each other, although I perfectly understand it shouldn't really (unless silly values) if they are say purely passive... But then they aren't perhaps?
I also understand your set up sounds better with mains filter, despite the prob you described. I like good mains filters aswell. I wonder if that better sound is due to your additional mains filter being "really" in front of the SMPS / amp section. It sounds unlikely to me given the high frequencies of the SMPS. I mean, given many filters are both ways, is the better sound really coming from filtering IN, or rather to the fact you are filtering high frequencies OUT of the SMPS/amp and cleaning mains for other devices?
Would you better sound be identical by putting your filters in front of all the other music playing components and leave the amp alone? That could help you having the best of both worlds : better sound without the problem, although I understand it would involve quite a bit more mains filters but then if you have one you can play with you could, as a start try it in front of several music playing devices to find the most benefical location.
Good luck
Claude
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Hi Claude ,do You think that is a general problem with all SMPS ? Just had a look at Hypex Datasheet,can`t find that Info.
Regards DT
Regards DT
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No clue about other SMPS sadly.
I couldn't find anything in their datasheet, but as I am following this thread and the one on Hypex amps since ages, I am quite sure somewhere, among the numerous pages, it has been made mention that mains filter could be detrimental. That rang a bell back then... As I use filters aswell.
Can't find it though and there are so many posts on both threads.
However, given the way the SMPS works (pumping fast?), it "could" make some sense that some device altering the current delivery / response speed at the input of the SMPS could possibly interfer.
I guess this filter bit is case by case and perhaps you are better off taking it out from the amp's input (as obviously it disturbs it) and just try to put it in front of your pre or source to see if you get a "better" sound again without troubling the amp's function.
MFG
Claude
I couldn't find anything in their datasheet, but as I am following this thread and the one on Hypex amps since ages, I am quite sure somewhere, among the numerous pages, it has been made mention that mains filter could be detrimental. That rang a bell back then... As I use filters aswell.
Can't find it though and there are so many posts on both threads.
However, given the way the SMPS works (pumping fast?), it "could" make some sense that some device altering the current delivery / response speed at the input of the SMPS could possibly interfer.
I guess this filter bit is case by case and perhaps you are better off taking it out from the amp's input (as obviously it disturbs it) and just try to put it in front of your pre or source to see if you get a "better" sound again without troubling the amp's function.
MFG
Claude
Its difficult to give a proper explanation of whats going on without some scope waves.
The "Sounds Better" with the filter, you mean better sounding, like better bass? more relaxed sound?
The "Sounds Better" with the filter, you mean better sounding, like better bass? more relaxed sound?