[Hun7er]

Hello,
 
I have noisy issue with my new amplifier, a Threshold SA30s. i use a Audio GD M7 DAC. My MCIntosh has also this issue but it is very very low.
I found that when I unplugged my laptop from the power cable I didn't have noise, it became just quiet.
 
So I'm thinking about buying a usb cleaner like aqvox or iusbpower. Other solution seems to go with a spdif/usb converter but my computer don't have optical connection and the newer dac will have better usb implementation.
 
Are these cleaner efficiently ? Which are the best ? There is more simpler and cheaper solution ?
 
All the best for new year

 

[arcorob]

It sounds like a ground noise issue. Are you using the laptop to feed the files ? But when you unplug it (battery power only ) the noise goes away ? That's a ground issue. You are going to want to isolate those lines , get the laptop into a different circuit.
 
USB cleaner is not going to fix that. What type of cable do you have ? A better grounded one may help BUT sounds like your power supply for the laptop is dirty. Try this...same setup but run a very long extension cord to a different cicuit in the house and run to the laptop, see if the ground noise is eliminated.

 

[Hun7er]

"Are you using the laptop to feed the files ?" YES
"But when you unplug it (battery power only ) the noise goes away ?"  YES. If I disconnect the USB câble I have the same result. The problem seems the USB that send interference.
 
"USB cleaner is not going to fix that. What type of cable do you have ?" usb cable from the DAC
 
"Try this...same setup but run a very long extension cord to a different cicuit in the house and run to the laptop ?" I tried on another electrical outlet but I have same problem.
 
 
"USB cleaner is not going to fix that." The problem isn't the 5 volts that are dirty ?
 
The previous owner didn't have the issue. He was using for the source a CD player. The amplifier was checked in 2012.

 

[Oklahoma]

The issue is where the interferience starts not what is transmitting it. If yiu unplug the usb cable and the interference stops that just means that cable is transmitting it not that it is causing it. Since the interference goes away when the laptop is ran on battery and not on the charger that shows it is coming from the wall power supply not the usb cable. Is the dac powered by usb or does the usb just transmit data? If it is just data you can try a cable that doesn't cary the 5v power and sometimes that can fix it, other times a beter cable can as well. Other than that you might want to try what you said with a usb to spdif adapter and run spdif into the dac as that cannot transmit the interference as it it optical.

Sent from my GT-N5110 using Tapatalk 4

 

[blitzxgene]

Try taping the 1 and 4 pins on the bit that plugs into laptop (the outer most pins) using electrical tape or whatever. They are the 5v and ground pins, which the Master 7 does not need. If that doesn't work, you could try something like the empirical audio short block which has filters for the data lines and also severs those pins too.
 
I'd tape those pins anyway as it has an improvement on sound quality, or at least it did for me.
 
(source, ref 10.32 and ears)

 

[conquerator2]

I'll try it.