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Uptone Audio Regen


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15 hours ago, thuandb said:

Hi Alex et al,

 

Sorry if the following question had been asked earlier.  Label me crazy, but I plan on using USB Regen to power one of 2 oMs that will arrive soon.  A DC cable with USB type A on one end and 5.5 / 2.1 one the other will connect USB Regen to the oM power input.  Does the USB Regen have enough juice to feed the oM?  The supplied MW 7.5V SMPS or ifi iPower 9v will power the USB Regen.

 

Thanks in advance for your thoughts.

 

that certainly isn't the design intent for the usb regen.  the power out from the regen was intended to provide the small amount of power a dac needs to negotiate the handshake with the usb source.

 

i would use an appropriate power supply

(1) holo audio red (hqp naa) > chord dave > luxman cl-38uc/mq-88uc > kef reference 1
(2) simaudio moon mind 2 > chord qutest > luxman sq-n150 > monitor audio gold gx100
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On 3/30/2020 at 7:40 PM, thuandb said:

Sorry if the following question had been asked earlier.  Label me crazy, but I plan on using USB Regen to power one of 2 oMs that will arrive soon.  A DC cable with USB type A on one end and 5.5 / 2.1 one the other will connect USB Regen to the oM power input.  Does the USB Regen have enough juice to feed the oM?  The supplied MW 7.5V SMPS or ifi iPower 9v will power the USB Regen.

 

Hi:  I am just now seeing your question (and the answers from other members). For some strange reason the forum dropped my "subscription" to this thread.

 

Actually, what you propose will work! :D

The 5VBUS regulator in the original USB REGEN is a 1-amp TI TPS7A4700.  We dedicated a 1A reg to VBUS because even though the USB 2.0 spec calls for devices not to draw more than 500mA (0.5A) each, there are some USB>S/PDIF converters and some portable DAC/headphone amps which go well over that (YellowTec and iFi Audio come to mind).

I do not know exactly how much current the opticalModule draws, but knowing the particular parts it is built with I am sure it is not more than about 700~800mA, likely less. So a USB REGEN should not have any problem powering a Sonore opticalModule from its 5VBUS output.  

 

Now the TI TPS7A4700 is ultra-low-noise regulator, but it is not an ultra-ultra-low-noise reg like the LT3042/45 as used in the oM (and EtherREGEN, ISO REGEN, UltraCap LPS-1.2). Still, it could be a nice "pre-regulator" to the opticalModule and an easy, on-hand alternative to an SMPS.

 

One caveat: To keep the heat down, don't power a USB REGEN used for this purpose with a 9V supply! The 4V drop from 9V to 5V at say 800mA would result in the reg and board having to dissipate 3.2 watts of heat.  The same load with the 7.5V Mean Well will lower that to a perfectly manageable 2 watts.

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  • 6 months later...

Hey, guys, 

Vbus2 has a compatibility list, and any of my DACs are on it. 

If I am to add Uptone Regen to this, say: 

PC > Vbus2 > USB Cable > Uptone Regen > USPCB A>B Adapter > DAC (PS Audio)
will any DAC then be recognizable by the PC or that DAC still must be Compatible with Vbus2? 

Or could that be that DACs such as PS Audio (DS DAC or Gain Cell DAC) won't benefit from such 'tweak'? 

Thank you!
Sergey

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3 hours ago, Sergey_S said:

Hey, guys, 

Vbus2 has a compatibility list, and any of my DACs are on it. 

If I am to add Uptone Regen to this, say: 

 

Hi Sergey:

 

The Vbus2 from SBooster does nothing more than disconnect Pin 1 of the USB cable, thus turning off 5VBUS by not passing it through.  A piece of tape on Pin1 would do exactly the same thing.

 

For the chain you show, with our original USB REGEN, the Vbus2 would do nothing because the USB REGEN already does not use or connect Pin 1.  The USB ignores that 5VBUS and dedicates a 1 amp ultra-low-noise regulator to producing clean 5VBUS at its output for DACs that need it. (Your PS Audio DAC, while not using VBUS to power much, does need to see VBUS for its initial "handshake" connection.)

 

Actually, I will correct myself here:

Since you are running a USB cable of some length from you computer to the USB REGEN, using the Vbus2 at the computer end to disconnect VBUS might have a very small benefit. The possible benefit would be not having the voltage running along the wire and capacitively coupling to it.  So you can try it and see here.

 

One important note to others that may read this:

Disconnecting VBUS leading into an UpTone REGEN can only be done for the original USB REGEN (of which there are close to 4,000 in the field).  Our ISO REGEN does require a tiny amount (20mA) of 5VBUS to power the upstream side of its Silanna galvanic isolator chip (though we even go overboard there and dedicate an ultra-ultra-low noise LT3042 to turn 5V into 3.3V for the chip, skipping the Silanna's internal reg.).

 

Regards,

--Alex C.

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36 minutes ago, Superdad said:

 

Hi Sergey:

 

The Vbus2 from SBooster does nothing more than disconnect Pin 1 of the USB cable, thus turning off 5VBUS by not passing it through.  A piece of tape on Pin1 would do exactly the same thing.

 

For the chain you show, with our original USB REGEN, the Vbus2 would do nothing because the USB REGEN already does not use or connect Pin 1.  The USB ignores that 5VBUS and dedicates a 1 amp ultra-low-noise regulator to producing clean 5VBUS at its output for DACs that need it. (Your PS Audio DAC, while not using VBUS to power much, does need to see VBUS for its initial "handshake" connection.)

 

Actually, I will correct myself here:

Since you are running a USB cable of some length from you computer to the USB REGEN, using the Vbus2 at the computer end to disconnect VBUS might have a very small benefit. The possible benefit would be not having the voltage running along the wire and capacitively coupling to it.  So you can try it and see here.

 

One important note to others that may read this:

Disconnecting VBUS leading into an UpTone REGEN can only be done for the original USB REGEN (of which there are close to 4,000 in the field).  Our ISO REGEN does require a tiny amount (20mA) of 5VBUS to power the upstream side of its Silanna galvanic isolator chip (though we even go overboard there and dedicate an ultra-ultra-low noise LT3042 to turn 5V into 3.3V for the chip, skipping the Silanna's internal reg.).

 

Regards,

--Alex C.

Thank you so much, Alex!
Now it's much clearer. I just tried the tape stripe and my PC doesn't see the DAC! 

I accidentally 😬 bought that Vbus2 thing without looking at compatibility list first! (I think I confused it's description with Uptone Regen description where I just need to connect it to anything as I was looking at many things that night).

And "https://www.audioaffair.co.uk/" (where I purchased Vbus2) never replied in this regard, so I guess I'm stuck with this device. Good thing it's not expensive. 

Anyway, since I am stuck with it, I thought to find some use of it, that's why I was thinking about getting an Original Uptone Regen. Seems like it's available at http://www.vortexbox.co.uk/.

I saw a few images on the Internet with Vbus2 connected to Uptone Regen and thought that should be a good use of Vbus2, better isolation etc, etc.. but seems like it doesn't make any sense to connect this way. 

I'm not quite sure what that means:
"The possible benefit would be not having the voltage running along the wire and capacitively coupling to it."
Does this mean that Vbus2 should be just connected somewhere else in the chain?

Like, say: PC > USB cable > Vbus2 > Uptone Regen > USPCB > DAC? 

Sorry if those are silly questions, it's just that when I connected Chord Mojo to this same PC I've heard those crazy ground loop noises coming out of the speakers. It's completely silent with the same speakers when I use MacBook Pro or other things like iPod or Cell phone. I disconnected PC's ground pin from the plug and it was silent, so I figured it's that ground loop noise people talk about. 

I've never heard this noise before however, and with PS Audio DACs it's also silent. But I'm just thinking, if that noise is somehow in the signal that is coming from this PC, maybe it somehow affects the music? 

It sounds ok from this PC's USB, but MacBook Pro sounds better (to my hearing) for some reason with the same DAC and Speakers using same Audirvana. 

Also, I like the sound much more that direct USB using USB Bluetooth Transmitter (Avantree Leaf) from the PC and BT Receiver connecting (Audioengine B1) it with Toslink cable to the DAC. Could that something to do with complete isolation from 5VBUS?

So that also makes me wonder whether something is messing with that direct USB signal. It's bit perfect, when I test it with DS DAC, but too "dry" and "boring" comparing to MacBook Pro or Bluetooth Connection. 

Maybe it's even better to get USB to SPDIF converter?

Thank you again, really appreciate your responses. 
Sergey
 

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17 minutes ago, Sergey_S said:

Thank you so much, Alex!
Now it's much clearer. I just tried the tape stripe and my PC doesn't see the DAC! 

 

Well the only place you can do that in your chain is at the PC. Your DAC does need VBUS--from the USB REGEN in your case.

 

17 minutes ago, Sergey_S said:

I'm not quite sure what that means:
"The possible benefit would be not having the voltage running along the wire and capacitively coupling to it."
Does this mean that Vbus2 should be just connected somewhere else in the chain?

What I meant was that your originally proposed chain [PC > Vbus2 > USB Cable > Uptone Regen > USPCB A>B Adapter > DAC (PS Audio)] has the benefit of keeping 5V off  of the USB cable from your computer to the REGEN (and since USB REGEN ignores VBUS you can get away with that).

 

17 minutes ago, Sergey_S said:

Like, say: PC > USB cable > Vbus2 > Uptone Regen > USPCB > DAC? 

No, disconnecting the VBUS just before the USB REGEN will do nothing at all because USB REGEN does not even have Pin 1 connected! But as explained above, if you put the Vbus2 connector at the computer end it might give some tiny benefit from not having the 5V running down the cable at all.

 

17 minutes ago, Sergey_S said:

Sorry if those are silly questions, it's just that when I connected Chord Mojo to this same PC I've heard those crazy ground loop noises coming out of the speakers. It's completely silent with the same speakers when I use MacBook Pro or other things like iPod or Cell phone. I disconnected PC's ground pin from the plug and it was silent, so I figured it's that ground loop noise people talk about.

Sorry, but I can not begin to unravel the mysteries of the various portable Chord DACs and what they do with power and ground connections. 9_9

 

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