Article: New AudioQuest DragonFly Cobalt

[mansr]

A word of caution: after plugging it in, the first volume change makes it jump to max regardless of what was requested. Over headphones, that could get unpleasant. Clearly a firmware bug.

[lucretius]

4 hours ago, mansr said:

A word of caution: after plugging it in, the first volume change makes it jump to max regardless of what was requested. Over headphones, that could get unpleasant. Clearly a firmware bug.

 

I noticed something like this on my Android phone -- fixed it by uninstalling, reinstalling UAPP, changing the volume steps from the default 20 to 100 within UAPP, and making sure the master hardware volume level was set for less than half of full output. 

 

I had a similar problem with the Red on my Android phone (never had this problem with an iPod touch). The problem seemed to reappear every time I loaded a new version of Android on my phone. I just assumed it was a problem with Android or Samsung hardware.

[mansr]

7 hours ago, lucretius said:

I noticed something like this on my Android phone -- fixed it by uninstalling, reinstalling UAPP, changing the volume steps from the default 20 to 100 within UAPP, and making sure the master hardware volume level was set for less than half of full output. 

 

I had a similar problem with the Red on my Android phone (never had this problem with an iPod touch). The problem seemed to reappear every time I loaded a new version of Android on my phone. I just assumed it was a problem with Android or Samsung hardware.

My PC does not run Android.

[lucretius]

20 minutes ago, mansr said:

My PC does not run Android.

 

I also tried on Windows.  However, I did not have my phones to my ears, when first plugging in the Cobalt. I did notice that it played loud and I just thought the volume control was too high.  I lowered the Windows volume control and all was fine.  Rebooting and/or reinsertions of the Dragonfly did not bring back the experience of jumping to full volume.

 

OTH,  the volume range of the Dragonfly Cobalt appears to map to a Windows volume range of 1 - 10 and not 1- 100. (That was similar for the Red as well.) That should be fixed in the Cobalt's firmware.

[mansr]

Just now, lucretius said:

I also tried on Windows.  However, I did not have my phones to my ears, when first plugging in the Cobalt.

 

I did notice that it played loud and I just thought the volume control was too high.  I lowered the Windows volume control and all was fine.  Rebooting and/or reinsertions of the Dragonfly did not bring back the experience of jumping to full volume.

 

OTH,  the volume range of the Dragonfly Cobalt appears to map to a Windows volume range of 1 - 10 and not 1- 100. (That was similar for the Red as well.) That should be fixed in the Cobalt's firmware.

The hardware range is 0-64. Software may choose to map that onto a different scale.

[lucretius]

12 minutes ago, mansr said:

The hardware range is 0-64. Software may choose to map that onto a different scale.

Yes.  Could it be that the firmware implements a linear control when that should be logarythmic?

[mansr]

44 minutes ago, lucretius said:

Yes.  Could it be that the firmware implements a linear control when that should be logarythmic?

It's a dB scale. That's easy to verify by measuring the output level.

[mansr]

OK, here's the proof it's a firmware bug. I connected a logic analyser to the USB and I2C ports. Then I sent a command to set the volume to the minimum of -64 dB (zero on the 0-64 scale). The volume control registers in the ESS DAC are coded as attenuation from max in half-dB steps. The requested volume thus corresponds to a value of 128. This is what actually happened:

 

 

The ESS volume control is first set to the correct value (80 hex = 128 decimal). Then it is immediately set to zero, which is maximum volume. The USB traffic is easier to see in a table view:

 

 

The highlighted line show the correct value being requested (C0 interpreted as a signed 8-bit value is -64). The remainder is the DAC indicating that it doesn't want to return any data to the host.

[mansr]

The max value is written to the volume control register after a somewhat random delay. In the capture above, it happened almost immediately. Sometimes it takes a few milliseconds.

[lucretius]

On 7/16/2019 at 9:35 AM, mansr said:

The max value is written to the volume control register after a somewhat random delay. In the capture above, it happened almost immediately. Sometimes it takes a few milliseconds.

 

You said earlier that this happens after plugging in the device and making the first volume change.  I assume that subsequent volume changes are fine (seems to be the case with my testing).  However, I still noticed that at a volume of about 10 or 11 or 12  in Windows, the actual volume was insanely loud and it was hard to notice any difference when moving the Windows system fader among the higher values. So I am assuming there is another issue in addition to the firmware issue you pointed out.

[rando]

The particular audio codec your mb uses?  Worth seeing if there is an updated driver or documentation.

[Gus141]

Anyone else not getting a magenta color on the LED for 96kHz music? My LED is white for 96kHz. I get all the other colors as described in the manual but 96kHz tracks make the Cobalt’s LED show white. Now, maybe it’s just a really faded magenta, but I’ve changed out enough printer cartridges to know what magenta looks like. Just thought I’d ask. I’ll post in other forums as well and report back.

 

Cheers

Gus 

[mansr]

4 hours ago, Gus141 said:

Anyone else not getting a magenta color on the LED for 96kHz music? My LED is white for 96kHz. I get all the other colors as described in the manual but 96kHz tracks make the Cobalt’s LED show white. Now, maybe it’s just a really faded magenta, but I’ve changed out enough printer cartridges to know what magenta looks like. Just thought I’d ask. I’ll post in other forums as well and report back.

I get white or possibly pale blue. The colour for 88.2 kHz is something I'd describe as yellow rather than amber, but I guess that's close enough.

[mansr]

6 hours ago, lucretius said:

You said earlier that this happens after plugging in the device and making the first volume change.  I assume that subsequent volume changes are fine (seems to be the case with my testing).

The first volume change after plugging in causes the glitch. After that it's fine.

 

6 hours ago, lucretius said:

However, I still noticed that at a volume of about 10 or 11 or 12  in Windows, the actual volume was insanely loud and it was hard to notice any difference when moving the Windows system fader among the higher values. So I am assuming there is another issue in addition to the firmware issue you pointed out.

The volume control runs from max (no attenuation) to -64 dB in 1 dB steps for a total of 65 different levels. I have no idea how Windows maps those onto its scale. It might not even be a linear translation. Does it use a custom Windows driver or the built-in Audio Class support?

[lucretius]

2 hours ago, mansr said:

The first volume change after plugging in causes the glitch. After that it's fine.

 

The volume control runs from max (no attenuation) to -64 dB in 1 dB steps for a total of 65 different levels. I have no idea how Windows maps those onto its scale. It might not even be a linear translation. Does it use a custom Windows driver or the built-in Audio Class support?

 

There is no proprietary driver for the Dragonfly. When plugging in the device for the very first time, Windows sets up an endpoint configured to use WASAPI -- I don't think Windows has it's own customized driver for this device. 

 

Also, are you sure those are 1db steps (or is each step just a percentage of full volume)?

[lucretius]

7 hours ago, Gus141 said:

Anyone else not getting a magenta color on the LED for 96kHz music? My LED is white for 96kHz. I get all the other colors as described in the manual but 96kHz tracks make the Cobalt’s LED show white. Now, maybe it’s just a really faded magenta, but I’ve changed out enough printer cartridges to know what magenta looks like. Just thought I’d ask. I’ll post in other forums as well and report back.

 

Cheers

Gus 

 

I got the blue color on the LED for 48, 88.2 and 96.  I don't know if that was an isolated case (i.e. your's may be different) or not.

 

[mansr]

6 minutes ago, lucretius said:

There is no proprietary driver for the Dragonfly. When plugging in the device for the very first time, Windows sets up an endpoint configured to use WASAPI -- I don't think Windows has it's own customized driver for this device. 

 

Also, are you sure those are 1db steps (or is each step just a percentage of full volume)?

I'm sure. The values go straight into the ESS chip where they (supposedly) represent dB attenuation. Also, the measured output level agrees.

[Gus141]

Thanks @mansr and @lucretius for describing your LED colors. A person responded on a Head-Fi forum that he also sees LED behavior that doesn’t match the manual. At least I know it’s not a problem with my DFC.

 

As for the volume discussion, I’ve only tried the DFC on an iPad so far and have not encountered the problem there. Should I expect it on a MacBook Pro?

 

Cheers

Gus

[mansr]

24 minutes ago, Gus141 said:

As for the volume discussion, I’ve only tried the DFC on an iPad so far and have not encountered the problem there. Should I expect it on a MacBook Pro?

I'd say, be prepared for it anywhere.

[lucretius]

11 hours ago, mansr said:

Quote

However, I still noticed that at a volume of about 10 or 11 or 12  in Windows, the actual volume was insanely loud and it was hard to notice any difference when moving the Windows system fader among the higher values. So I am assuming there is another issue in addition to the firmware issue you pointed out.

The volume control runs from max (no attenuation) to -64 dB in 1 dB steps for a total of 65 different levels. I have no idea how Windows maps those onto its scale. It might not even be a linear translation. Does it use a custom Windows driver or the built-in Audio Class support? 

 

For my Dragonfly Red, the Windows volume control maxes out at about 30 to 35 (after 35 it's all full volume). I could live with that, since there's still enough room to make meaningful sound level adjustments; however, for the Dragonfly Colbalt I tested, the Windows volume control maxed out much sooner -- making meaning sound level adjustments much more difficult.

[mansr]

7 minutes ago, lucretius said:

For my Dragonfly Red, the Windows volume control maxes out at about 30 to 35 (after 35 it's all full volume). I could live with that, since there's still enough room to make meaningful sound level adjustments; however, for the Dragonfly Colbalt I tested, the Windows volume control maxed out much sooner -- making meaning sound level adjustments much more difficult.

Is that on a 0-100 scale? Guess I should hook it up to a Windows machine and see what's going on. The Windows driver could very well be doing something strange.

[lucretius]

1 hour ago, mansr said:

Is that on a 0-100 scale? Guess I should hook it up to a Windows machine and see what's going on. The Windows driver could very well be doing something strange.

 

Yes, the Windows fader is in a 0-100 scale.

[Graham Luke]

On 7/8/2019 at 11:17 PM, firedog said:

Everyone has had the same blurb today (sorry Chris) but I'd like to actually hear from someone who has heard it and compared it to the Red and other inexpensive DACs like iFi.

John Darko has auditioned one; great video available from Berlin.

[stuck limo]

On 7/12/2019 at 4:49 PM, lucretius said:

 

I believe the volume issue related only to Android phones -- Android was limiting the output. This has been corrected (at least for my phone) with updates.  There was never a problem with Windows 10, AFAIK.

 

The volume issue I'm referring to was for Windows for (at least) the Dragonfly Black. You'd get to literally volume level 2 or 3 and the DAC would be

MAX VOLUME

ANDALMOSTORCOMPLETELYBLOWOUTYOUREARDRUMSANDYOUREQUIPMENT.

[lucretius]

1 hour ago, stuck limo said:

 

The volume issue I'm referring to was for Windows for (at least) the Dragonfly Black. You'd get to literally volume level 2 or 3 and the DAC would be

MAX VOLUME

ANDALMOSTORCOMPLETELYBLOWOUTYOUREARDRUMSANDYOUREQUIPMENT.

 

Ouch!  Was the issue corrected later in firmware?  (E.g. With my Dragonfly Red, I could go up to about Windows volume 30-35 before hitting full volume.)