DC-1

[garbulky]

Feb 8, 2015 21:51:04 GMT -5 TheMachinist said:

I got the BigBear USB2ISO to use with DC-1, but am having problems running with it anything above 44KHz. the DC-1 is on USB 2.0 mode and the isolator is rated Full Speed so in theory should be able to hit 96KHz sampling.


Anyone using USB Isolator with good effect with DC-1, please share some info.

Not all ports are rated as USB 2. Restart the computer first (sometimes when there is an error, it resets to USB 1), then plug the DC-1 in (into a DIFFERENT USB slot).
Also....especially if you use a PC, you may only get 44.1 or 48khz output until you use WASAPI mode which is windows "bit perfect" mode. Without it windows likes to resample everything to a lower resolution.

[wiskers]

You can also use asio.

[TheMachinist]

Feb 8, 2015 22:03:22 GMT -5 garbulky said:

Not all ports are rated as USB 2. Restart the computer first (sometimes when there is an error, it resets to USB 1), then plug the DC-1 in (into a DIFFERENT USB slot).
Also....especially if you use a PC, you may only get 44.1 or 48khz output until you use WASAPI mode which is windows "bit perfect" mode. Without it windows likes to resample everything to a lower resolution.

Well I have already tried all that before, and with different PC/DAC got different results. With Audiolab 8200CD the BigBear isolator runs till 96KHz.
I am running Windows with FooBar2K and WASAPI. Without the isolator DC-1 can hit 192 and all frequencies in between with no issues. With the BigBear isolator it is limited to 44. So I wonder if the BigBear is incompatible with the DC-1, or as a matter all USB isolator base on ADuM4160 are incompatible.

The isolator works for me to remove ground loop hum, but due to limitation seeking anyone else on similar path  would recommend a USB isolator tried and tested with DC-1. Meanwhile, I may resample all audio to 44HZ on the fly in foobar using SoX resampler.

[garbulky]

Feb 8, 2015 23:25:38 GMT -5 TheMachinist said:

Feb 8, 2015 22:03:22 GMT -5 garbulky said:

Not all ports are rated as USB 2. Restart the computer first (sometimes when there is an error, it resets to USB 1), then plug the DC-1 in (into a DIFFERENT USB slot).
Also....especially if you use a PC, you may only get 44.1 or 48khz output until you use WASAPI mode which is windows "bit perfect" mode. Without it windows likes to resample everything to a lower resolution.

Well I have already tried all that before, and with different PC/DAC got different results. With Audiolab 8200CD the BigBear isolator runs till 96KHz.
I am running Windows with FooBar2K and WASAPI. Without the isolator DC-1 can hit 192 and all frequencies in between with no issues. With the BigBear isolator it is limited to 44. So I wonder if the BigBear is incompatible with the DC-1, or as a matter all USB isolator base on ADuM4160 are incompatible.

The isolator works for me to remove ground loop hum, but due to limitation seeking anyone else on similar path  would recommend a USB isolator tried and tested with DC-1. Meanwhile, I may resample all audio to 44HZ on the fly in foobar using SoX resampler.

You know that is a very curious error. You obviously have tried everything I would have. Are you by any chance having the DC-1 hooked into the USB isolator when you plug the isolator in? If so, you may want to plug the isolator in first and then wait a bit in case there's some sort of wierd driver that needs starting up and then plug in the dc-1. Hmmm.... No idea why it should be incompatible.
The DC-1 has an onscreen set up menu for USB one of the options on it says USB 1.1 which it may accidentally be set at limiting it to 44.1

[KeithL]

I'll get back to you guys on that tomorrow - I just happen to have a Big Bear isolator in my desk. I've used it to eliminate computer ground noise with dongle-DACs like the DragonFly, but those top out at 24/96 anyway - which the Big Bear can definitely do. So far I haven't run into a situation where isolating a DC-1 was actually necessary. However, as someone else already mentioned, the Big Bear supports USB 2.0 Full Speed (12 mBps) but not USB 2.0 High Speed (480 mBps), and I suspect that this may prevent it from handling any rates above that. (That is a limitation of the ADuM4160 isolator and, unfortunately, I'm not aware of any even reasonably inexpensive USB 2.0 Full Speed galvanic isolators.)

I'm not quite sure if the raw bit rate at 24/192 falls just under or just over that 12 mBps limit, but I'll check it for you guys tomorrow and let you know.

[TheMachinist]

Feb 8, 2015 23:40:44 GMT -5 garbulky said:

You know that is a very curious error. You obviously have tried everything I would have. Are you by any chance having the DC-1 hooked into the USB isolator when you plug the isolator in? If so, you may want to plug the isolator in first and then wait a bit in case there's some sort of wierd driver that needs starting up and then plug in the dc-1. Hmmm.... No idea why it should be incompatible.
The DC-1 has an onscreen set up menu for USB one of the options on it says USB 1.1 which it may accidentally be set at limiting it to 44.1

The isolator is invisible to the OS. It needs no drivers. However I tried both ways with and without DC-1 plugged into the isolator, and various other combinations. The DC-1 is running in USB 2.0 mode.

Big Bear have listed many DACs incompatible on their support page here., so I suspect DC-1 could also be incompatible.

[unsound]

Feb 9, 2015 2:05:19 GMT -5 TheMachinist said:

Feb 8, 2015 23:40:44 GMT -5 garbulky said:

You know that is a very curious error. You obviously have tried everything I would have. Are you by any chance having the DC-1 hooked into the USB isolator when you plug the isolator in? If so, you may want to plug the isolator in first and then wait a bit in case there's some sort of wierd driver that needs starting up and then plug in the dc-1. Hmmm.... No idea why it should be incompatible.
The DC-1 has an onscreen set up menu for USB one of the options on it says USB 1.1 which it may accidentally be set at limiting it to 44.1

The isolator is invisible to the OS. It needs no drivers. However I tried both ways with and without DC-1 plugged into the isolator, and various other combinations. The DC-1 is running in USB 2.0 mode.

Big Bear have listed many DACs incompatible on their support page here., so I suspect DC-1 could also be incompatible.

I've used it with the DC-1 at 96/24 several months back. I wasn't having any issues with hum, so I took it out of the chain and seem to have misplaced it. If I find it, I'll verify and let you know.

[KeithL]

I just tried mine (Big Bear USB isolator) this morning with my XMC-1 (which uses the same USB interface as the DC-1) and wasn't able to get it to work at all. (With my Amazon Basics 3 meter USB able, which is what I normally use on my desk, and my Dell desktop machine, I was unable to get ANY sample rates to work - and it appeared as if the driver wasn't loading correctly.) As I think I mentioned in another post, I've used the Big Bear plenty of times before to eliminate computer ground noise with various USB-powered "dongle DACs" like the DragonFly, and it always worked great, but those were all UAC1 (24/96 / driverless) devices. However, since I've never had ground noise issues with an AC-powered USB DAC, I don't honestly recall whether I've ever tried the Big Bear with a DC-1 or XDA-2 before.

As has also been mentioned, since the Big Bear supports "USB 2.0 Full Speed" but NOT "USB 2.0 High Speed" it is NOT technically fully compliant with USB 2.0 . Because of this, it may have compatibility issues with certain devices, or with certain combinations of USB ports and cables, or even with specific versions of the driver or specific driver modes, and may not work properly with all of them. I don't think this is a "bit rate" issue so much as a "compatibility" issue. Unfortunately, galvanic isolators that ARE fully USB 2.0 compliant are few and far between - and aren't cheap. (If I'm right and it is a compatibility issue, then other isolators that only support USB 2.0 Full Speed may work just fine - or they may not. There are a few out there that use different isolator chips; if anyone finds one that works consistently at all sample rates, do please let us know )

I would say that the Big Bear can be trusted to work with UAC1 devices (like the XDA-1), but I would consider it to be "try it at your own risk" with the XDA-2g2, the DC-1, and the XMC-1.

Feb 9, 2015 3:10:56 GMT -5 unsound said:

Feb 9, 2015 2:05:19 GMT -5 TheMachinist said:

The isolator is invisible to the OS. It needs no drivers. However I tried both ways with and without DC-1 plugged into the isolator, and various other combinations. The DC-1 is running in USB 2.0 mode.

Big Bear have listed many DACs incompatible on their support page here., so I suspect DC-1 could also be incompatible.

I've used it with the DC-1 at 96/24 several months back. I wasn't having any issues with hum, so I took it out of the chain and seem to have misplaced it. If I find it, I'll verify and let you know.

[TheMachinist]

Thanks Keith for clarifying. You are always there to set things right.

As I mention with the Big Bear the DC-1 max out at 44KHz, which is still not a bad thing as it does cover my CD rips which is major part of my music collection, and gives a background devoid of ground loop noise.

[unsound]

Feb 9, 2015 11:51:22 GMT -5 TheMachinist said:

Thanks Keith for clarifying. You are always there to set things right.

As I mention with the Big Bear the DC-1 max out at 44KHz, which is still not a bad thing as it does cover my CD rips which is major part of my music collection, and gives a background devoid of ground loop noise.

I did find my Big Bear and I can confirm that 44/16 is the max I can get out of it to the DC-1. Like Keith, I had trouble getting the PC to even recognize the DC-1 with the Big Bear in place.

[rckt]

I read about the big bear here, got it and reported the issue a while back (I guess it was on that thread).
I'm now using the schiit wyrd "decrapifier" and it works perfectly well and does not cost that much.

[TheMachinist]

Feb 21, 2015 18:39:45 GMT -5 rckt said:

I read about the big bear here, got it and reported the issue a while back (I guess it was on that thread).
I'm now using the schiit wyrd "decrapifier" and it works perfectly well and does not cost that much.

That is good news. It seems to be a voltage regulator, DC isolator to provide ground loop and a signal reclocker. The later would be same function as ASRC in the DC-1, and the DC-1 would do without the usb 5V so a voltage regulator may not be absolutely necessary ? It's only the galvanic isolation that would benefit the DC-1. I dun know I could be wrong, just taking a analytical dig at it.

Head Fi details the internals:
USB repeater chip (SMSC USB2412) with internal crystal oscillator for timing (24MHz, +- 350ppm), and a voltage regulator (UA723C, aka LM723) with a low tested output noise voltage (2.5uV). But the USB repeater chip is actually using a external even lower jitter 20ppm master clock instead of internal 350ppm.

Source : www.head-fi.org/t/724519/schiit-decrapifier-released-usb-power-isolator/30#post_10721198

This would make my Paul Pang V2 usb card redundant which is using a 24MHz TCXO to reclock the USB bus data.

[Tungx2]

Hello,

Sorry for the newbie question.

I'm new to the headphone world and I don't know where to begin.

I got a DC-1, it's on its way actually. It's mostly for late night movies and sometimes music.

I'm wondering what equipment do I need? My sources won't be very good at the moment. Mostly consist of HD versions of songs I downloaded online, I don't have much flac content. So the music source will be Airplay to Marantz SR6009 from an iphone using wifi/bluetooth. For movies, it'll be coming out of my PS3.

Also, I currently have Marantz SR6009. Based on the reviews on DC-1, I should probably bypass Marantz SR6009 and plug the DC-1 straight into the optical out of my ps3? (I'll maintain my HDMI connection from ps3 to the receiver, just that I know the optical out will be 2 channel.)

Headphones - I was looking at Sennheiser HD 598 at $150. Good bang for the buck, but hey, if I got a DC-1, why not go wild and go for HD 700 (waiting for $600 deal) or HD 800 (HD 800 is a bit crazy, even at $1200 discounted price at the moment)

Also, does it require and external amp to drive those? Or can I just plug in most headphones and the DC-1 can drive them to most headphone's potential?

Thanks in advance.

[moovtune]

The headphone output on the DC-1 should drive your phones very well - it sounds great.

[garbulky]

Feb 23, 2015 16:55:13 GMT -5 Tungx2 said:

Hello,

Sorry for the newbie question.

I'm new to the headphone world and I don't know where to begin.

I got a DC-1, it's on its way actually. It's mostly for late night movies and sometimes music.

I'm wondering what equipment do I need? My sources won't be very good at the moment. Mostly consist of HD versions of songs I downloaded online, I don't have much flac content. So the music source will be Airplay to Marantz SR6009 from an iphone using wifi/bluetooth. For movies, it'll be coming out of my PS3.

Also, I currently have Marantz SR6009. Based on the reviews on DC-1, I should probably bypass Marantz SR6009 and plug the DC-1 straight into the optical out of my ps3? (I'll maintain my HDMI connection from ps3 to the receiver, just that I know the optical out will be 2 channel.)

Headphones - I was looking at Sennheiser HD 598 at $150. Good bang for the buck, but hey, if I got a DC-1, why not go wild and go for HD 700 (waiting for $600 deal) or HD 800 (HD 800 is a bit crazy, even at $1200 discounted price at the moment)

Also, does it require and external amp to drive those? Or can I just plug in most headphones and the DC-1 can drive them to most headphone's potential?

Thanks in advance.

The DC-1 drives the sennheiser HD600's "decently". Basically what that means is that it's about as good as an entry level standalone headphone amp like the one I have for about $130. It definitely does it better than say an XDA-2. It should do allright with the HD800. But....the HD800's are one of the best headphones in the world. They shine with some really class amplification (read: amp with balls). But they'll do all right with the dc-1. But...the HD800's are ridiculously good, just saying.
A more appropriate pairing would be a schiit molnir or something similar maybe a level down $850
schiit.com/products/mjolnir

or one of these
www.littledot.net/forum/viewtopic.php?f=9&t=871&sid=25e4eedb0a9aaa4490093c07ece4d5a3

The lyr 2 (tube amp) $500
schiit.com/products/lyr-2

Little dot mkV solid state ($300) dual mono amp
www.littledot.net/forum/viewtopic.php?f=9&t=817&sid=f82b356bbbaafb6703ec3000d042313b

[TheMachinist]

Feb 22, 2015 23:58:17 GMT -5 TheMachinist said:

Feb 21, 2015 18:39:45 GMT -5 rckt said:

I read about the big bear here, got it and reported the issue a while back (I guess it was on that thread).
I'm now using the schiit wyrd "decrapifier" and it works perfectly well and does not cost that much.

That is good news. It seems to be a voltage regulator, DC isolator to provide ground loop and a signal reclocker. The later would be same function as ASRC in the DC-1, and the DC-1 would do without the usb 5V so a voltage regulator may not be absolutely necessary ? It's only the galvanic isolation that would benefit the DC-1. I dun know I could be wrong, just taking a analytical dig at it.

Update and Correction: The Schiit Wyrd does not do true galvanic isolation (here). It injects 5V but the ground plan is common across all. Also it reclocks the data signal. Big question: Isn't that same as ASRC on the DC-1 ??

When you tried the Schiit Wyrd is the DC-1 ASRC on ?

[KeithL]

The ASRC on the DC-1 acts to remove jitter from digital audio originating from ALL of the DC-1's inputs.

More or less independently of that, the asynchronous USB input on the DC-1 controls the clocking for the USB input, eliminating jitter on the USB input itself.
(Technically an asynchronous USB input doesn't "reclock" the data; the clocking on the USB port is controlled by the DAC instead of the computer to begin with. This is still the way it works, even if the ASRC is disabled.)

The Schiit Wyrd re-clocks and "buffers" the USB DATA PACKETS - before they even get to the USB input on the DAC.
(This does NOT ensure that the signal will be jitter free after it is converted into digital audio by the USB received circuitry.)
The Wyrd also cleans up the +5v DC supply that is part of the USB signal (it's a pin on the USB cable; on USB-powered DACs, this 5v is what powers the DAC, but not on AC-powered DACs like the DC-1.)

If you're concerned about galvanic isolation, you should also know that the Coax S/PDIF inputs on the DC-1 are galvanically isolated (by transformers), and ALL Toslink inputs on any device inherently provide perfect galvanic isolation.

As for the Wyrd... IN THEORY:

* If you have the ASRC enabled on the DC-1, then audio from any of the inputs on the DC-1 is reclocked by the ASRC, and it should sound the same whether you use the USB or S/PDIF inputs on the DC-1 (and do or don't use the Wyrd).
* If you have the ASRC DISABLED, since a S/PDIF or Toslink source may or may not have a lot of jitter, and it isn't being removed by the DC-1, those sources could possibly sound different because of that jitter.
    However, even with the ASRC disabled, the USB input on the DC-1 is still asynchronous, and so clocks the USB data the DC-1 receives, and so should still be immune to jitter on USB audio inputs.
* Since the USB input on the DC-1 is asynchronous, and so is immune to jitter on the incoming data (regardless of whether the ASRC is enabled or not), and the DC-1 isn't powered by the 5v on the USB line, the Wyrd shouldn't make any difference whatsoever with the DC-1.

The main situations where you should expect the Wyrd to possibly make an audible difference would be: 

* USB-powered portable DACs that run off the +5v line in the USB connection (like the Modi 2 and the DragonFly) - because it provides a cleaner source of +5v power for them.
* DACs with USB inputs that are NOT asynchronous and DON'T have an ASRC or other method of eliminating jitter - because it's possible that buffering the packets will somehow enable the USB receiver circuitry to deliver a cleaner digital audio signal.
    (Not all DACs have asynchronous USB inputs... including a lot of low cost ones, and even - still - a few expensive ones. Some of those may be sensitive to a poor quality USB data signal, in which the Wyrd might deliver an improvement.)

Feb 24, 2015 8:58:53 GMT -5 TheMachinist said:

Feb 22, 2015 23:58:17 GMT -5 TheMachinist said:

That is good news. It seems to be a voltage regulator, DC isolator to provide ground loop and a signal reclocker. The later would be same function as ASRC in the DC-1, and the DC-1 would do without the usb 5V so a voltage regulator may not be absolutely necessary ? It's only the galvanic isolation that would benefit the DC-1. I dun know I could be wrong, just taking a analytical dig at it.

Update and Correction: The Schiit Wyrd does not do true galvanic isolation (here). It injects 5V but the ground plan is common across all. Also it reclocks the data signal. Big question: Isn't that same as ASRC on the DC-1 ??

When you tried the Schiit Wyrd is the DC-1 ASRC on ?

[TheMachinist]

Thanks Keith, that clarifies that in theory ASRC is the Schiit Wyrd reclocking equivalent. It just shows how much tech and features is packed within the DC-1.

I was somewhat unclear why we need ASRC on top of Async USB implementation if the later successfully kills all USB jitter. I got some informative explanations here and here explaining that USB receiver itself creates problems for the DAC clock. Its mind boggling.

Now I like to explore using a USB to SPDIF converter to tap the galvanic isolated inputs of the DC-1. Not sure if the cure will be worse than the disease. Options are to use a cheap XMOS/CM6631A based one off eBay, or get a MF V-Link 192 USB to spdif which  specifically does some degree of galvanic isolation (limited to low frequency level using Yuan Dean Scientific 30T-2521NL transformers) on all outputs including AES/EBU output. Using that with the DC-1 SPDIF inputs would mean double isolation at the MF SPDIF outs and DC-1 SPDIF inputs. That with ASRC Enabled to eliminate jitter could be a possible solution to solve ground loop hum and maintain jitter free.

[TheMachinist]

Feb 24, 2015 11:32:11 GMT -5 KeithL said:

If you're concerned about galvanic isolation, you should also know that the Coax S/PDIF inputs on the DC-1 are galvanically isolated (by transformers), and ALL Toslink inputs on any device inherently provide perfect galvanic isolation.

Does that include AES/EBU ?

[KeithL]

Yes, the AES/EBU input is transformer isolated....

Feb 25, 2015 7:48:07 GMT -5 TheMachinist said:

Feb 24, 2015 11:32:11 GMT -5 KeithL said:

If you're concerned about galvanic isolation, you should also know that the Coax S/PDIF inputs on the DC-1 are galvanically isolated (by transformers), and ALL Toslink inputs on any device inherently provide perfect galvanic isolation.

Does that include AES/EBU ?