I have an old Commodore 64 brick linear power supply. I measured it with a digital multimeter and it works great, regardless of age, so I decided to experiment. It works in Class A and gets quite hot all the time, regardless if there is a power user switched to it. It measures very stable 5V and 1.7A, which is good enough for USB 3.0 (5V, 1.5A).
I bought a powered USB hub and of course it came with a cheap generic phone charger. however, I used the Commodore 64 PSU to power the USB hub.
I used 2 small bits of tape to isolate the power and ground rails in the USB Type A plug that goes in the back of my PC. This means when I plug the USB hub to the PC, it only gets the 2 rails for data and is electrically isolated from the grounding and doesn't use the PC USB 5V that come from the nasty switching PSU.
Using a powered USB hub also helps maintain the integrity of the data signal sent through the data rails, which means you can use longer USB cables without getting intermitent signal. The USB hub works both as a repeater and power source in this case.
I then plug my USB powered DAC in the hub and it works. The hub receives 1.7A current if required by the DAC, which is nice with headphones and very peaky dynamic digital recordings.
Does it help?
Fortunatly the test is simple and doesn't require ABX. You listen with everything turned all the way up and without any music playing. The rubbish I could hear while the DAC was powered from my PC was not insignificant, like I was hearing AM radio. I plug it in the hub and I got less noise and louder + cleaner output.
Since the Commodore brick did a nice job, I decided to order a new LPSU at 5V and I'll see how that one works out. The brick is a bit fugly TBH. That vintage computer yellowish gray that used to be white...
Anyways, one quirk with this. It's recommended to have the LPSU powered by the UPS that you use for your PC to prevent shutdown during power outages. Remember we cut off the 5V rail from the PC USB source.
I bought a powered USB hub and of course it came with a cheap generic phone charger. however, I used the Commodore 64 PSU to power the USB hub.
I used 2 small bits of tape to isolate the power and ground rails in the USB Type A plug that goes in the back of my PC. This means when I plug the USB hub to the PC, it only gets the 2 rails for data and is electrically isolated from the grounding and doesn't use the PC USB 5V that come from the nasty switching PSU.
Using a powered USB hub also helps maintain the integrity of the data signal sent through the data rails, which means you can use longer USB cables without getting intermitent signal. The USB hub works both as a repeater and power source in this case.
I then plug my USB powered DAC in the hub and it works. The hub receives 1.7A current if required by the DAC, which is nice with headphones and very peaky dynamic digital recordings.
Does it help?
Fortunatly the test is simple and doesn't require ABX. You listen with everything turned all the way up and without any music playing. The rubbish I could hear while the DAC was powered from my PC was not insignificant, like I was hearing AM radio. I plug it in the hub and I got less noise and louder + cleaner output.
Since the Commodore brick did a nice job, I decided to order a new LPSU at 5V and I'll see how that one works out. The brick is a bit fugly TBH. That vintage computer yellowish gray that used to be white...
Anyways, one quirk with this. It's recommended to have the LPSU powered by the UPS that you use for your PC to prevent shutdown during power outages. Remember we cut off the 5V rail from the PC USB source.
Facebook
Twitter
Instagram