[Cornan]

  Just a clarification:  
 
I'm sure that when you wrote...
 

 Blocking the power AFTER the USB Regen is just as important.

 
... you meant:   
 
Blocking the power AFTER the USB Regen is just as important when using a DAC that is self-powered - that does not require 5V power from the USB cable.

Yes of course! It just gets so monotonous writing "that does´nt need 5v power and/or handshake" in every other sentence. Thanks for making it clear for everyone!

 

[zilch0md]

^ I thought I would "head them off at the pass."

 

[rb2013]

 
Well the REGEN ignores the pin-1 5VBUS line anyway (it provides very clean and quiet VBUS out using the best-in-class 1A TI TPS7A4700 regulator and a few caps), so neither the iPurifier2 or the iUSB ever see any draw from their VBUS line.
 
In fact, when using a REGEN (n its correct/best place as the last item before the DAC), unless you put the iUSB before the iPurifier2, then the iUSB really is not doing ANYTHING for your chain.  When you look at the iUSB board, you can see the data lines going straight from input to output--nothing but jacks and traces.  And while the iUSB may produce a very clean 5VBUS voltage (hopefully better than the REGEN given all the room and circuitry they have), it is ignored by the REGEN--and you don't even run it since you say you don't connect the power leg of your Gemini cable out of the iUSB.
 
Just sayin'...

My thinking is the iPurifier2 should be at least as accurate as far as impedence as the Regen adpater - not like a USB cable.  And it may add additional benefits from it's reclocking (anyone have any idea on the clocks they use?) and filter functions.  Or maybe not - so the ears will tell the story.
 

  Since the USB Regen is blocking ALL power coming in from the USB source there is actually no point using ANY power before the Regen. Due to the capacitive coupling inside the USB cable (negative interference between power and data since they all being very close to each other) there is however a good point having NO power before the USB Regen. Any improvements (if any) with iUSB and iPurifier2 in front of the Regen would be in the data and ground lines only. A short USB cable is also important. The only way for you to tell if it is beneficial or not for your sound is to try it your self. The outcome very much depends on your system and your own sound preferences.
 
Blocking the power AFTER the USB Regen is just as important. The reason is still the same, ie capacitive coupling. However, judging by the sound improvement by removing the supplied short adapter (which should have minimal capacitive coupling) I guess that it in some way also reduces the capacitative coupling inside the USB Regen itself as well. Please understand that this is my assumption only. All I know is that here is definitely a great improvement blocking the power in the USB cable AFTER the Regen as well. However, when you receive your Konvertible Lite 160 you will find out the SQ difference your self. I personally love that cable!
 
I would recommend that you start simple with Gemini (no power leg)>USB Regen>K-Lite160>DAC and after you have listen to familiar tracks you add the iUSB>iPurifier2>Mercury and listen to the very same tracks. Choose what you think sounds the best in your system. However, I am not sure if Gemini have the GND wire together with power or together with data wires? If Gemini have the ground wires together with the power wires you will not be able to do the simple setup since GND is needed for the handshake....and no GND is not beneficial for the sound unless you are using a star ground and unshielded USB cables (K-Lite is unshielded but Gemini/Mercury is not).

Yes - that capacitive coupling issue maybe why I'm getting good results by using a VBUS blocker modded Jitterbug at the PC USB for the data line feed on the 2G split cable. 

 

[Cornan]

Since I have'nt been clear enough in some details I want to clear out any issues so no one new to this thread missunderstand my points:

1. USB Regen ignores any power coming in and do not need any incoming power what so ever since it supplies the USB power needed for the DAC. No need to worry about anything. Any DAC will work with a USB cable without 5v power before the USB Regen. Removing 5v power is a great improvement for any DAC and works for everyone.

2. USB Regen do supply the power after the USB Regen for any DAC that needs both power and handshake. Cutting the power is very beneficial after the USB Regen as well but there are a few things to keep in mind here:
* If your DAC needs the power
* If your DAC needs the handshake
The most simple to test if your DAC does'nt need any of these are to cover USB pin no 1 with electrical tape. If everything works your DAC does'nt need power or handshake. Great! Just go ahead and cut the USB power!

However, If your DAC does'nt work you will need to dig in a little deeper by checking threads about your perticular DAC and/or asking the manufacturer what is needed for your specific DAC.

Let us say that your DAC do not need the power but requires a handshake. Now you will need to know that both power and GND is needed for the handshake...but is just needed a brief moment during the handshake. The handshake is done when the driver is recognized by your computer/source. When the driver is recognized it is OK to remove the power from the USB cable for better SQ.

Now comes a problem. What cable to use? Right now there is only one cable that I know of that could do this for you unless you make a DIY cable. If you do not have DIY skills check out the Elijah Audio Konvertible Lite.

Last issue will be the GND (ground). Is there a way to connect just data wires between your computer/sourse and the Regen/DAC without GND? Yes there is...but it is fairly complicated. You will need to make sure that you have a proper star ground and unshielded cables between the computer/source and Regen/Dac. Before you try it out make sure to cover pin 4 on the USB cable to check if it works without the ground. However, it could work if you have a ground loop as well...so making sure that there is no ground loop present and that you have a proper star ground is essential for success here! If not properly done you will only experiance a bad sound...but with a proper setup you will have the best sound possible. Well worth a persue if you ask me. I am not there yet...but I am slowly heading there!

I hope this will help to clear things up a bit! Good luck!

 

[rb2013]

Since I have'nt been clear enough in some details I want to clear out any issues so no one new to this thread missunderstand my points:

1. USB Regen ignores any power coming in and do not need any incoming power what so ever since it supplies the USB power needed for the DAC. No need to worry about anything. Any DAC will work with a USB cable without 5v power before the USB Regen. Removing 5v power is a great improvement for any DAC and works for everyone.

2. USB Regen do supply the power after the USB Regen for any DAC that needs both power and handshake. Cutting the power is very beneficial after the USB Regen as well but there are a few things to keep in mind here:
* If your DAC needs the power
* If your DAC needs the handshake
The most simple to test if your DAC does'nt need any of these are to cover USB pin no 1 with electrical tape. If everything works your DAC does'nt need power or handshake. Great! Just go ahead and cut the USB power!

However, If your DAC does'nt work you will need to dig in a little deeper by checking threads about your perticular DAC and/or asking the manufacturer what is needed for your specific DAC.

Let us say that your DAC do not need the power but requires a handshake. Now you will need to know that both power and GND is needed for the handshake...but is just needed a brief moment during the handshake. The handshake is done when the driver is recognized by your computer/source. When the driver is recognized it is OK to remove the power from the USB cable for better SQ.

Now comes a problem. What cable to use? Right now there is only one cable that I know of that could do this for you unless you make a DIY cable. If you do not have DIY skills check out the Elijah Audio Konvertible Lite.

Last issue will be the GND (ground). Is there a way to connect just data wires between your computer/sourse and the Regen/DAC without GND? Yes there is...but it is fairly complicated. You will need to make sure that you have a proper star ground and unshielded cables between the computer/source and Regen/Dac. Before you try it out make sure to cover pin 4 on the USB cable to check if it works without the ground. However, it could work if you have a ground loop as well...so making sure that there is no ground loop present and that you have a proper star ground is essential for success here! If not properly done you will only experiance a bad sound...but with a proper setup you will have the best sound possible. Well worth a persue if you ask me. I am not there yet...but I am slowly heading there!

I hope this will help to clear things up a bit! Good luck!

I cut the VBUS +5VDC and the Ground leads on a Jitterbug USB output - so it acts as both a ground disconnect and a VBUS blocker.  $49 and a simple 15 min operation.  It works great and sounds amazing. 
 




I just clipped the 1 and 4 pins on the out bound USB connector (the jitterbug needs power to function).  So only the data leads are active.  This works great with the 2g Split cable - and with or without the Regen.   Just run the data only line after the modded JB plugged in to the PC.  With the Regen it supplies the USB with power (if needed).  Or without the Regen just plug the power leg of the 2G into a Li Ion battery or LPS power source set for 5VDC.

 

[Cornan]

@rb2013 Thanks. I think you would be interested in this thread http://www.computeraudiophile.com/f10-music-servers/vbus-isolator-sbooster-26228/
Very interesting read about cutting the GND.

 

[Superdad]

  I cut the VBUS +5VDC and the Ground leads on a Jitterbug USB output - so it acts as both a ground disconnect and a VBUS blocker.  $49 and a simple 15 min operation.  It works great and sounds amazing. 

I just clipped the 1 and 4 pins on the out bound USB connector (the jitterbug needs power to function).  So only the data leads are active.  This works great with the 2g Split cable - and with or without the Regen.   Just run the data only line after the modded JB plugged in to the PC.  With the Regen it supplies the USB with power (if needed).  Or without the Regen just plug the power leg of the 2G into a Li Ion battery or LPS power source set for 5VDC.

 
Great, now you just need to cut out and jumper across the common-mode choke that the Jitterbug has on its data lines and it will sound even better.  Oh wait, after that and what you have already done to it, it will just be a USB A>A circuit board!

 

[rb2013]

   

I like the sound of the Jitterbug - I have a second unmodded in an open USB port .  They are not earth shattering - but add a bit of flow and ease to the proceedings.
 
I use them in both my WIN10 iCore 7 main system and my WIN7 iCore 5 office system to good effect.
 
So why would I want to cut their common mode filter for?????  I trust my ears and they Likey.

 

[paulchiu]

My Regen arrived about 12 hours ago.  I started testing it through my problematic chain of 2014 Macbook Pro 15" with 1TB internal flash card to Hugo to various headphones.
Listening to tracks I have heard over 200-300 times on Shure 846, Telos fujisan and HiFiman he1000.
 
Noticed right away, things are more quiet.  Heard on the hugo the lip parting of singers I get with Nagra HD DAC headamp.  A first time.
More importantly, I opened the bluetooth of the Macbook Pro and did numerous I/Os with NAS and other USB3 chains without any clicks, pops or booms.
 
So far, much better than the Audioquest Jitterbug in that regard. (alone in the picture)
 

 

[zilch0md]

I like the sound of the Jitterbug - I have a second unmodded in an open USB port .  They are not earth shattering - but add a bit of flow and ease to the proceedings.

I use them in both my WIN10 iCore 7 main system and my WIN7 iCore 5 office system to good effect.

So why would I want to cut their common mode filter for?????  I trust my ears and they Likey.

He was just kidding.

 

[guzmanatm]

I understand no jitterbugs, iPurifiers, or 'decrapifiers' should be placed between the Regen and DAC in order to receive the greatest benefits in terms of signal integrity and impedance matching that the Regen provides. With that in mind would connecting a Regen directly to the iFi Micro iDSD, which has iPurifier built in, defeat the purpose of using the Regen? Technically there would be no devices between the Regen and Micro iDSD, but does the fact that the iPurifier technology is still in the audio chain reduce or blunt the positive effects that the Regen is supposed to be providing?

 

[rb2013]

He was just kidding.

Well tongue in cheek.  OP are great guys and have excellent customer service.  But have a certain - 'attitude' shall we say. 
 
The cutting of the VBUS output pins on the Jitterbug in no way diminishes it's true purpose of reducing noise on the USB bus.  Using a modded one to also act as a VBUS block is just another benefit.  Certainly more elegant then his suggestion of taping over the pins.
 
Just sayn'
 
Now suggesting a JC-1 LPS (a fine unit - but $925) to power a $200-$400 USB bridge is well a little extravagant in my book. 
 
Or comparing a $59 new USB DDC (the Rui Yi Audio X1) to a $2800 one is well let's say apples and oranges.
 
Here it the new X1 using the latest XMOS processor the XU208 (twice the through put as the U8) and ultra low noise USB and audio clocks, 4 layer board, etc...
 

  Product Description:

   X-1 digital interface of our team to develop a high-performance USB digital audio interface, using the XMOS latest xCORE-200 series chips. X-1 is the rare Japanese KDS low jitter TCXO clock digital system interface. X-1 digital interface using standard USB2.0  input interface, while X-1 has a wealth of output interfaces, including coaxial RCA and I2S interfaces.

Features:

1, X-1 is the first use of XMOS latest xCORE-200 series USB interface digital products. New generation XMOS chip, using more advanced process technology, performance than the older U8 chip doubled, reaching 1000MIPS processing capabilities.

2 , it is known, the core of the algorithm is heavy digital audio. Our team in the field of digital audio work for many years, at the same time get XMOS FAE support team, we conducted a number of technical improvements and optimization algorithms on the basis of the original firmware.

Specifications:

Each output interface supports sample rates:

PCM: 44.1KHz, 48KHz, 88.2KHz, 96KHz,

    176.4KHz, 192KHz, 352.8KHz, 384KHz

    [ Wherein I2S out support full sample rate , S / PDIF supports up to 192KHz]

DSD: 2.8 MHz (DSD64) - DoP, native

    5.6 MHz (DSD128) - DoP, native

    11.2 MHz (DSD256) - native

    [ Wherein I2S out support all DSD format , S / PDIF and AES / EBU support DSD64 DOP mode ]

Bits wide: the highest 32 bit over I2S output

      The highest 24 bit over S / PDIF

Each interface electrical standards:

1 , USB input socket is a standard USB-B type female, USB power supply range 4.5V-5.1V ;

2 , RCA connector outputs standard S / PDIF  signal level is 550mV ( standard connection load ), the output impedance of 75 ohms; 

Design details:

1 , carry out electricity as the mother of the acoustic design concept, pay attention to the power supply circuit design, high-performance, low noise and fast response of the LDO as the main power source. The entire board using a 2 -way independent of the LDO power supply, wherein the clock even partially adopted ADI 's ultra low noise LDO , in order to ensure the ultimate output performance laid a solid foundation.

2 , PCB motherboard with 4 -layer circuit board design, make sure you have a complete ground plane and power planes, high-speed digital design methods to ensure signal integrity and power integrity of the entire board. The clock signal special treatment, the use of package design and precise impedance control, thereby ensuring the signal quality and increase the clock anti-jamming capability. Input and output signals are to follow standard design, especially USB high speed signals using a 90 ohm differential impedance control.

I ordered one to see how it sounds with or without the Regen.  $59 - is silly cheap.

 

[BernieK]

  Hi Bernie, I am arranging with a local Adelaide customer (using Curious link between Regen/DAC) to audition/compare a K-lite 160 and a K-lite 500( between PC/Regen) I will post his comments ASAP
Michael

 
Hi Michael,
 
Saw some preliminary comments about the Elijah Konvertible Lite vs the Curious Cables, but nothing solid since. How's the comparison going?
 
Cheers,
 
Bernie

 

[dmbr]

I understand no jitterbugs, iPurifiers, or 'decrapifiers' should be placed between the Regen and DAC in order to receive the greatest benefits in terms of signal integrity and impedance matching that the Regen provides. With that in mind would connecting a Regen directly to the iFi Micro iDSD, which has iPurifier built in, defeat the purpose of using the Regen? Technically there would be no devices between the Regen and Micro iDSD, but does the fact that the iPurifier technology is still in the audio chain reduce or blunt the positive effects that the Regen is supposed to be providing?

I'd be quite interested in the answer to this question myself.

But how do you "know" that no other cleaning devices should be added to the chain?

 

[Michael P]

Hi Bernie, nothing yet, but keeping my fingers crossed for a report by the end of this week