What do the wires between the dac and the amp look like? Are they single-shielded unbalanced coax? Is there a large area between the two coaxes or are they close together? Does moving around the wires change the noise at all?
Any idea where the EMI in the air is coming from? Light dimmers? Florescent lights? Start turning everything off in the room to see if you can track it down.
Any idea where the EMI in the air is coming from? Light dimmers? Florescent lights? Start turning everything off in the room to see if you can track it down.
It seems it is not coming from my computer, I don't have any neon , or cfls or any other wall wart.
I do have 2 ceiling cheap LED stuff but I don't use it much,
Thanks Markw4, I'll move the wires around.
They are cheap Belkin two strand of copper per wire, single ended but they connect into a SS amp with OPAMP balanced input, so the ground and (-) are linked at the connector, the connector is a 3 prong balanced (hifi which cost me a fortune)
I don't want to purchase a balanced DAC with new interconnects because I know this will be expensive.
The power amp is quiet if I disconnect it , or if the DAC is ON. I only need the USB disconnect which I will receive Monday to get rid of the computer noises.
I do have 2 ceiling cheap LED stuff but I don't use it much,
Thanks Markw4, I'll move the wires around.
They are cheap Belkin two strand of copper per wire, single ended but they connect into a SS amp with OPAMP balanced input, so the ground and (-) are linked at the connector, the connector is a 3 prong balanced (hifi which cost me a fortune)
I don't want to purchase a balanced DAC with new interconnects because I know this will be expensive.
The power amp is quiet if I disconnect it , or if the DAC is ON. I only need the USB disconnect which I will receive Monday to get rid of the computer noises.
That could be a problem. Just for test purposes you might move things closer together and try some shorter and better wires. You might also see if connecting the ground wire from the dac to the amplifier ground helps. It may or may not do anything good, but probably worth a check.
Playing with the grounds is impossible, there are also too many wires involved,
My dac is a huge box filled with 2 transformers, 2 huge chokes, tons of film caps and 3 tubes and the bare Emu0404 skeleton. what is left of it.
The wires to the amps are 1 m , so the amps are close to speakers, they each have their power supply on the floor, which are Switching... so I cant switch off the amps to see if the noise disappear LOL
My dac is a huge box filled with 2 transformers, 2 huge chokes, tons of film caps and 3 tubes and the bare Emu0404 skeleton. what is left of it.
The wires to the amps are 1 m , so the amps are close to speakers, they each have their power supply on the floor, which are Switching... so I cant switch off the amps to see if the noise disappear LOL
Have you ever considered running your DAC on a battery and keeping the cable runs short? Then you shouldn't have any EMI problems anymore.
It comes from my computer which is just there in the middle in part. It is a bit quieter when the computer is off.
But the mail contributor is that steel frame on the table.
I tried wiring the power modules through my Variac or the wall plug, no difference.
1, point to note: the variac is not happy feeding the SMD power supplies, it has bouts of ringing and humming for no apparent reasons.
So it is the quietest when:
1. Wires are disconnected from AMP (computer has no influence) (silent)
2. Wires are connected to DAC which is ON , computer is off, (very little noise)
3. Wires are connected to DAC which is ON , computer is ON, (a little bit more noise)
3. Wires are disconnected from DAC , but away from the metal table (slight noise)
4. Wires are disconnected from DAC , close to metal table, (noise is perceptible)
5. Wires are connected to DAC and dac OFF , computer is off (a lot of hum and noise)
6. Wires are connected to DAC and dac OFF , computer is on (multiple types of hum and noises)
What is very weird is that I have a lot of DAC power supply noise through computer in the TUBE amp when volume is up.
But it doesn't affect much my SS amp.
I cannot leave the DAC on all the time to get the noise to a lower level...
I don't think batteries would change anything to the AMP input wires catching noises.
But the mail contributor is that steel frame on the table.
I tried wiring the power modules through my Variac or the wall plug, no difference.
1, point to note: the variac is not happy feeding the SMD power supplies, it has bouts of ringing and humming for no apparent reasons.
So it is the quietest when:
1. Wires are disconnected from AMP (computer has no influence) (silent)
2. Wires are connected to DAC which is ON , computer is off, (very little noise)
3. Wires are connected to DAC which is ON , computer is ON, (a little bit more noise)
3. Wires are disconnected from DAC , but away from the metal table (slight noise)
4. Wires are disconnected from DAC , close to metal table, (noise is perceptible)
5. Wires are connected to DAC and dac OFF , computer is off (a lot of hum and noise)
6. Wires are connected to DAC and dac OFF , computer is on (multiple types of hum and noises)
What is very weird is that I have a lot of DAC power supply noise through computer in the TUBE amp when volume is up.
But it doesn't affect much my SS amp.
I cannot leave the DAC on all the time to get the noise to a lower level...
I don't think batteries would change anything to the AMP input wires catching noises.
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I decided not to power my power amps modules through the filtering which changes nothing to them. They have powerful switching power supplies.
So I instead placed the computer, the screen, the phono, the dac and the tube amp on the Variac ,
Again the DAC has another filter after just for itself.
So I instead placed the computer, the screen, the phono, the dac and the tube amp on the Variac ,
Again the DAC has another filter after just for itself.
I have now the adum 4166 + IT and chokes to intercept the computer USB out.
I could not hear any difference with the DAC connected or Disconnected from the computer.
Same with tube amp, it completely isolated the computer noise... it makes a subtle difference!!!
I could not hear any difference with the DAC connected or Disconnected from the computer.
Same with tube amp, it completely isolated the computer noise... it makes a subtle difference!!!
Maybe you should connect the PC to the DAC via an optical cable, then you have a perfect galvanic isolation, without noise
I would have to install a sound card with optical out in my PC, for now the adum 4166 works well, I will try with another amplifier which is more sensitive to amplify computer noise.
So far so good!!!
So far so good!!!
Sounds unbelievably good!!! before all it was was THD and noise before the filters and new amplifiers, new loudspeakers.
And this , probably the highest resolution recording which I ever had the chance to listen to:
The singers are here with me, it is more than enjoyable.
(I listen of course to the paid CC high resolution versions, links for suggestions)
I just tested tonight, the costly USB (DAC) isolator did nothing to filter computer noise ,
For some reasons it is amplified through the dac and only appears on the KT88 tube amplifier.
It comes from the computer through the DAC line, no idea how it goes through the dac , if it is by polluting the ground or in the DAC chip itself, it is impossible to tell without much help.
For some reasons it is amplified through the dac and only appears on the KT88 tube amplifier.
It comes from the computer through the DAC line, no idea how it goes through the dac , if it is by polluting the ground or in the DAC chip itself, it is impossible to tell without much help.
no its emu0404, it only does this problem in one amp...
the output are sent to tubes broskie unbalance, that is the biggest mod I did. I am sure it doesn't have anything to do with it.
I isolated that it comes from the CPU and Video card mostly, through the USB cable.
Then something happens in the dac and this signal is somewhat sent through everything ...
I causes the problem in the tube amp, the signal is an audible whining choke sound which coincides with screen activities or image movement in a game, etc.
It is very faint but i want to get rid of it.
(sorry for long post), actually the adum 4166 module just caused jitter and introduced weird low level rushing and beating noises, just audible close to loudspeakers when music plays softly
the output are sent to tubes broskie unbalance, that is the biggest mod I did. I am sure it doesn't have anything to do with it.
I isolated that it comes from the CPU and Video card mostly, through the USB cable.
Then something happens in the dac and this signal is somewhat sent through everything ...
I causes the problem in the tube amp, the signal is an audible whining choke sound which coincides with screen activities or image movement in a game, etc.
It is very faint but i want to get rid of it.
(sorry for long post), actually the adum 4166 module just caused jitter and introduced weird low level rushing and beating noises, just audible close to loudspeakers when music plays softly
Is there a ground loop through the amplifier from the PC power ground all the way to the amplifier ground? Does the power amp have a hum-breaker circuit?
Also, is everything in the system all connected to AC line power through one single power strip? If not, you might try that.
Also, is everything in the system all connected to AC line power through one single power strip? If not, you might try that.
mmm I have no clue how to check for ground loop beside disconnected the ground which is not very easy to do on commercial connections unless I hax things up...
The amp has no filter of anything, however ... it is on the same AC line but connects through this:
DC caps(diodes) // line break +/- then emf filters, then Variac power transfor ,
The Dac is connected through another set of DC caps etc...
So the green (ground) is the only wire which the power supplies are built upon as reference... but I doubt there is any loop.
I cannot make my power amp work without the ground reference, ahhh
The dac is NOT grounded but the tube output is referenced to ground.
= if I turn off the computer it goes away
= if I turn off the dac it goes away.
= If I disconnect the USB from either dac or computer it goes away.
its through that USB cable, mostly due to power, which I have no clue why the ADUM isn't breaking this.
I don't have the option of using another circuit breaker. I could use a huge power cord to try...
I doubt it is ground loops, no idea how it could form also.
I wonder if I convert the USB to I2S ...
I connected directly to the dac of my computer and it is horrible, the sound is plagued with all sorts of computer noises
its 20x more terrible than connected to the external emu dac
The amp has no filter of anything, however ... it is on the same AC line but connects through this:
DC caps(diodes) // line break +/- then emf filters, then Variac power transfor ,
The Dac is connected through another set of DC caps etc...
So the green (ground) is the only wire which the power supplies are built upon as reference... but I doubt there is any loop.
I cannot make my power amp work without the ground reference, ahhh
The dac is NOT grounded but the tube output is referenced to ground.
= if I turn off the computer it goes away
= if I turn off the dac it goes away.
= If I disconnect the USB from either dac or computer it goes away.
its through that USB cable, mostly due to power, which I have no clue why the ADUM isn't breaking this.
I don't have the option of using another circuit breaker. I could use a huge power cord to try...
I doubt it is ground loops, no idea how it could form also.
I wonder if I convert the USB to I2S ...
I connected directly to the dac of my computer and it is horrible, the sound is plagued with all sorts of computer noises
its 20x more terrible than connected to the external emu dac
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What happens if you hit pause on the playback? What if you stop playback? All it needs the dac powered up and receiving data? What if you leave the dac output ground connected to the power amp but disconnect the audio signal from going into the power amp? IOW, is it just noise coming out of the output signals when the dac is playing?
its the computer noise related to functioning of video and cpu.
I hear the cpu and video making noises through the dac , it can be 'software' disconnected it still plays the noise.
It is not related to playing music or silence.
i will try to disconnect the ground in just one RCA pulling it out slowly and just keeping the + pin in. if it is possible, or link it, just one channel.
I hear the cpu and video making noises through the dac , it can be 'software' disconnected it still plays the noise.
It is not related to playing music or silence.
i will try to disconnect the ground in just one RCA pulling it out slowly and just keeping the + pin in. if it is possible, or link it, just one channel.
Don't pull the ground. Pull the + signal only. Then if you still have noise its coming in on the ground.
If there is a ground loop, it will be through your USB cable, your audio cables, and back through the power amp AC line ground, through your house ground system, and back to the PC AC line ground. That's a BIG loop.
If there is a ground loop, it will be through your USB cable, your audio cables, and back through the power amp AC line ground, through your house ground system, and back to the PC AC line ground. That's a BIG loop.
Its not in the ground.
I disconnected the ground on one RCA , the noise was almost as high
Then I disconnected just one RCA completely noise is gone in that channel.
The connected channel has the noise.
I disconnected the ground on one RCA , the noise was almost as high
Then I disconnected just one RCA completely noise is gone in that channel.
The connected channel has the noise.