Y cable Tweak for the USB powered DAC

[vijwilso]

Just wanted to post my recent experiment with the Y-Cable and External power.

The idea is to provide the clean power to the DAC , bypassing the power from the PC .

In the Y-Cable , Only Data is transmitted from the computer and the power is from the external battery , 5V .

I manually covered the +ve and -ve lines of the USB pins on the computer side with the insulation tape ( it is not hard as it looks ) so that it will transmit only the data.

Attached a picture of the arrangement .
Note ::: I dont use MAC for as the source My source is windows Desktop PC .

 

[vijwilso]

BTW , if anyone wanted to try , the battery is cheap ~600 Rs which is a mobile backup battery pack from Reliance Digital , 'rconnect' is the name of the product . The battery spec is 5V , 1Amps lithium ion, so it should be able to provide enough current for most of the USB powered DACs. If you don't see improvement in sound , you can use the battery for the mobile backup. It is worth the try.

 

[gobble]

I am looking for a similar mobile battery source as is available in most stores but one that can supply 2 to 3 amps of current for 3 hours. Any ideas which brand model?

Purpose is same - to power the cubox music source and usb-spdif convertor for listening.

G0bble

 

[vijwilso]

Is your device requires 2-3 Amps current ? The batter pack designed for tablets might provide 2-3 amps , but they are expensive

 

[all4music]

won't the powered USB hub provide the similar effect? one does not have to worry about charging the battery either..

 

[Thad E Ginathom]

I am powering my ODAC from a USB hub. I have no idea of it makes things better or worse. It's just a plain, cheap, 4-port hub: I wonder what the quality of the power is?

In an ideal world, we would not only take the USB power from a clean sourse, we would also isolate the signal cables. By the time we've done all this it might have been easier and cheaper to buy a different DAC

I have tried the HiFiMeDIY isolator, as I was ordering a DAC and the extra cost was minimal. It is a failure. It severely compromises the sound: not so much drawing a veil across it, more like obstructing it with a concrete wall!

I'm tempted to try this ifi unit but at SGD269, again, the answer might be just buy another DAC.

The ifi iDSD Micro has all sorts of fancy power stuff built in to it, but at SGD649 is whole step or two up the budget ladder.

(Prices, Singapore Dollars, from Stereo, Singapore, but ifi do have an Indian dealer... there is a thread here)

 

[vijwilso]

won't the powered USB hub provide the similar effect? one does not have to worry about charging the battery either..

I tried once with a powered USB house , there was a audible noice with that power source, it depends on the quality of the power supply of the USB hub. Battery is pure power source for the cheaper price.

 

[vijwilso]

In an ideal world, we would not only take the USB power from a clean sourse, we would also isolate the signal cables.

I can understand isolation of the power . Can you elaborate the isolation of the signal , why it is required and what it does . What do we isolate in the signals , isn't just the stream of data correct ?

 

[Thad E Ginathom]

Not sure, vijwilso. In fact I might even be getting a touch of audiophile paranoia here --- browsing too many audio forums :lol:

The stream of data should, indeed be correct. I suppose there is a chance of interference from the source entering the cable and being carried to the destination. I don't know how this works, or doesn't work, which is, of course, always a starting point for paranoia .

The other side of that coin is that there is always a chance that there isn't any noise on the USB cable.

There is no audible sound from my USB ODAC when not playing music, not even at full time. I don't think there was before the hub either. I put the hub because of a strange thing where switching on the powered speaker would cause some sort of voltage drop and the PC would "loose" the ODAC.

 

[vijwilso]

Not sure, vijwilso. In fact I might even be getting a touch of audiophile paranoia here --- browsing too many audio forums :lol:

The stream of data should, indeed be correct. I suppose there is a chance of interference from the source entering the cable and being carried to the destination. I don't know how this works, or doesn't work, which is, of course, always a starting point for paranoia .

The other side of that coin is that there is always a chance that there isn't any noise on the USB cable.

There is no audible sound from my USB ODAC when not playing music, not even at full time. I don't think there was before the hub either. I put the hub because of a strange thing where switching on the powered speaker would cause some sort of voltage drop and the PC would "loose" the ODAC.

Thad , My take is that as long as the receiving device is able interpret the incoming data , there is no issue with the noise in the data signal . We transfer files sized several GBs to the Pendrive over the USB . And without any error recovery/retransmission mechanism with the USB MSC , we never encounter any errors in the file transfer (like corrupted files, failed copy etc ) so far . the success rate should be more than 99.99%
So the audiophile grade DAC should be able interpret the incoming data with whatever noise in the signal . Honestly don't understand the ifi iPurifier product with their explanation/advantage on the noise reduction of signal.

I think the hub that i used was not a good one ( i remember it was from belkin )

Do i see improvement with the Battery tweak ? I think , yes , based on my memory, but that is very unreliable , need to do side-by-side comparison and i don't have the normal cable with me now . Exchanged the normal cable with the Ycable . Need to get a normal cable .

 

[Thad E Ginathom]

My take is that as long as the receiving device is able interpret the incoming data , there is no issue with the noise in the data signal

Now that's the sort of thing I usually say! I guess I'd better check out those cables in my head

 

[saheb11123]

Just wanted to post my recent experiment with the Y-Cable and External power.

The idea is to provide the clean power to the DAC , bypassing the power from the PC .

In the Y-Cable , Only Data is transmitted from the computer and the power is from the external battery , 5V .

I manually covered the +ve and -ve lines of the USB pins on the computer side with the insulation tape ( it is not hard as it looks ) so that it will transmit only the data.

Attached a picture of the arrangement .
Note ::: I dont use MAC for as the source My source is windows Desktop PC .

Did you find difference in sound quality, when you have plugged directly to usb taking power from usb vs when powering from the external battery?

 

[vijwilso]

Did you find difference in sound quality, when you have plugged directly to usb taking power from usb vs when powering from the external battery?

I think yes . There was improvement with the battery powered USB .

However i could not do extensive comparison on it and currently i have the stereo packedup in ward-robe due to construction activities

 

[Thad E Ginathom]

Couple of new [to me] things on the USB power front.

One is the Schiit Wyrd "USB Decrapifier." Schiit are careful not to make any claims at all, User reviews seem to indicate that it is implementation dependent. If you happen to have the problem it solves, it might well solve it. It is US$99

The other is the Olimex USB-ISO isolater. EURO-29.95 plus suitable power adapter if you need the USB power. It's designed purpose is to protect the PC from equipment that might carry high voltages but audio users have reported benefits. See: Link to head-fi

 

[gobble]

The general opinion amongst audiophiles is that If an isolator has a transformer, it will likely degrade the sound.

G

 

[dheerajin]

If any power conditioning circuit is incorporated in isolating device, then there may be chances of degradation of sound. If only transformer is used, then there is no chance of any degradation. Medical devices are more sensitive to any noise available in electrical signal. Thats why they are supplied power from isolation transformer. No medical hospital uses so called power conditioners.
However in this thread , nowhere there mentioned any transformer. USB is low powered device and suggested power isolaters are not based on transformers.

The general opinion amongst audiophiles is that If an isolator has a transformer, it will likely degrade the sound.

G

 

[gobble]

Some examples of audio devices with transformer for galvanic isolation of USB, and some without: www.thewelltemperedcomputer.com/HW/USB_SPDIF.htm

G

 

[hemantwaghe]

I am looking for a similar mobile battery source as is available in most stores but one that can supply 2 to 3 amps of current for 3 hours. Any ideas which brand model?

Purpose is same - to power the cubox music source and usb-spdif convertor for listening.

G0bble

Rahul how about Xiomi power bank 10400 mAh

Mi 10400 mAh Power Bank - Mi : Flipkart.com

check when it is available ..possibaly finest stuff available for 1 K , myself planning to buy 2-3 ( 2 for mobiles , 1 for audio) have seen it personally , phenomenal build!

Only issueneed to check availabality!

 

[gobble]

Rahul how about Xiomi power bank 10400 mAh

Mi 10400 mAh Power Bank - Mi : Flipkart.com

check when it is available ..possibaly finest stuff available for 1 K , myself planning to buy 2-3 ( 2 for mobiles , 1 for audio) have seen it personally , phenomenal build!

Only issueneed to check availabality!

Already using portronics 12000mah since a few months. Good improvement over PSU.

 

[Thad E Ginathom]

Here's another industrial-strength USB power supply. it has the advantage of 4 USB ports.

Vaunix Lab Brick

But at $199 it does not have the advantage of being cheap!