 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
76.173.115.53
Appears Opticis usb extension cable is used by quite a few inmates. Short of spending $189, is there an affordable diy way to galvanically isolate the PC from one's usb dac?Context: My dac has a female type-b usb connector on the chassis that plugs into Doede's usb-to-i2s board. This board is powered by a seperate 18v power supply. Haven't yet decided how far the pc will be from rack; if it's in the other room, I'll get the opticis. But if PC is close to rack, don't need 3meter+ extension, but want the galvanic isolation. Any thoughts?
Follow Ups:
I isolate PC from DAC by using the S/PDIF output from USB chip through a tranny. Yes, I get a lot of grief for adding this extra step, which can possibly add jitter. But for me, I more prefer the isolation as a feature. Besides, I reclock the DAC anyway, so the extra conversion doesn't cause me the usual headaches. I get the best of both worlds, low jitter AND isolation.Another thing you can do is to wrap a the USB cable several turns through a ferrite core. This will act as a common mode balun and isolate at RF. Won't do anything for hum, but will remove spurious clock or other unrelated HF noise.
jh
and if I were taking i2s out of the usb receiver, would it be an option to route this into a transformer to isolate? I think the i2s interface uses 3 wires.
I had been using the Opticis with a battery power supply for my PC given that it was 65 feet from the USB Dac.Today I connected the Opticis to my MacBook Pro with a short Kimber USB cable. I used the Wavelength Crimson DAC.
There is a definite improvement using the Opticis. Without it, I could not get the total power of a big drum on several symphonic recordings. The soundstage increased slightly. A purer midrange and highs resulted with better definition.
The sound of the Crimson is amazing, but I could not understand why it would not deliver the power at the bottom octave. Insert the Opticis, and I'm home again.
Steve
Steve (Mercman) - forgive the dense question, but I'm battling a head cold now and my brain is a little foggy. I'm a little unclear as to how the Opticis is used. Did you mean to say you tried the Opticis with your MacBook Pro INSTEAD of the Kimber USB cable or IN ADDITION TO?In other words, does the Opticis connect directly to devices or does it still need another cable? And if your DAC or other USB sound device is self-powered, do you still need to supply power to the Opticis?
Thanks for any clarification!
Edward,The Opticis works like a USB hub. It comes with its own power supply, but I use a battery to power it. You have to plug a USB cable into the end of the Opticis to connect your Dac. The Opticis works with a PC or Mac.
Steve
It is possible using a couple of different isolation buffers, but none of the currently available USB DAC's do this to my knowledge. I believe the problem might be the bidirectionality of the USB bus. If the lines were unidirectional, this would be easy, but they are not. The drivers are transceivers.Steve N.
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
