AudioQuest DragonFly 24/96 Asynchronous USB DAC / Headphone Amp

[Wavelength]

AudioQuest worked extensively with Gordon Rankin from Wavelength Audio to develop the DragonFly. The DAC does not contain StreamLength code but nonetheless is an async design from Gordon.

 

Chris,

 

Yes of course this is Streamlength and yes only Class 1, but this makes it more compatible with all operating systems. Yes Linux is included in that as well as Windows without a driver and of course OSX.

 

The headphone amplifier is 125mw unit so it's pretty hefty for such a small size. Because of the power required for the amplifier/line + analog volume control we could not keep the current draw below the iPad minimum for use with the Camera Connection kit.

 

Thanks

Gordon

[Wavelength]

Gang,

 

Sorry, but for some reason I was not getting this thread?

 

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Volume control...

 

Many dacs do digital volume control for those work like this:

 

Interface (SPDIF, USB Firewire) --->DAC===> output

 

Here the Interface usually by means of what is called I2C or SPI controls variables in the dac chip to alter the output volume.

 

In the DragonFly like the Proton this is done in the analog domain as follows:

 

Interface--->DAC===>Output Driver + Volume===>

 

Here the Interface uses I2C to talk to the output driver + volume control to change the volume in the analog domain.

 

Above --- is I2S digital audio stream and === is analog voltage.

 

USB allows volume conditioning directly which is used here. This means the volume control is part of the system wide volume control located on the system tool bar and NOT in the application. While some direct interfaces do allow these two to be linked.

 

~~~~~~~~

 

Halide HD and DragonFly

 

Companies who work with me to deliver USB dacs can have me design the unit totally or do everything except the interface themselves. Halide designs their own dac circuitry and output designs. I only work on the USB interface section with them. For the DargonFly I did all the design except for the enclosure. Acceptance was done as a team the way all AudioQuest products are designed.

 

There will be a "Dragon Tail" at some point which has the same look feel as the DragonFly it self and will look as an extension.

 

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Yes this will work with Linux...

 

30 PIN IOS is limited to 32/192 at this point but you would need special hardware and app to do that.

 

I think I answered everyone's questions.

 

Thanks

Gordon

[Wavelength]

Chris,

 

I am still not getting any notifications.

 

Answers...

 

Development on this was done over about 8 to 10 months. Kind of a funny story... I said lets do this and AQ wanted a dac with minimum phase filters. So we made a couple of dacs with the Wolfson 8741 and cap coupled and direct coupled and differential and single ended and if you don't know this every example costs about $10K to do. So we made up five different samples and they all were evaluated by the team and we were getting closer. I said look let me make what I originally suggested and I will pay for it if you don't like it. Well that is what is shipping! There are 107 components on a 0.6"x1.7" four layer board including a ton of regulators and expensive custom capacitors.

 

3.5mm Do understand that at AudioQuest it's all about the metal. Both the USB connector and the 3.5mm connector are custom one off pieces made with high audio grade silver contacts. If we would have put RCA connectors on these it would have been on wire and what kind of an upgrade path would that have had? nothing!!!!! If we would have put RCA connectors on the unit then it would have been bigger you have to put them at least 0.75" apart and nothing would have fit the model AudioQeust wanted.

 

I did a ton of work on the output stage to make it compatible with both line and headphone. I think it works really well with both as it has more drive than required for line and easily 2x more drive for headphones.

 

Flavors...

 

Look there are a lot of flavors of dacs out there. Everyone seems to be an expert but none of you have listened to all of them so really keep your mouth or fingers off the keyboard. None of us listen the same way or for the same purpose. It's like guitars... you don't hear musicians calling foul on guitars they just don't buy them. Audiophiles should be more like that and really go out an listen before you purchase or make comments.

 

Thanks

Gordon

[Wavelength]

I was wondering if Gordon or anyone could tell us the output impedance for this DAC- important for low impedance IEM headphones.

 

Tim,

It should work fine with IEM's low impedance, the spec sheet says 12ohms minimum load, but I think that is to keep their specs true. Most of the IEM's are greater than that anyways.

 

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Gang,

 

Look nobody is an expert at listening. Everyone does it differently and that is why talking about products is not as good as listening to them. I assume that some people buy and try and I have nothing against that. But I think you would be better served to go listen to something before you buy it.

 

Thanks

Gordon

[Wavelength]

What I would like to know is what is Gordon working on now that does go into my Vintage McIntosh amp?

 

Well the NAMM show is mid July so I am working on my iKodek 500 series 32 bit AD/DA converter. I am also going to show my new guitar amplifier series Dingo and V1.

 

 

Ed Robertson BNL back stage with his Dingo Combo Amplifier - Red Rocks, Colorado

 

As for dacs.... sorry have to keep that stuff private

 

Thanks

Gordon

[Wavelength]

Brandal,

 

The output impedance of the DragonFly is 0.8 ohms max.

 

You cannot determine this low of output impedance using a fluke meter!

 

Guys really????

 

Thanks

Gordon

[Wavelength]

Can Gordon or some please chime in on this?

 

My OCD tells me I will wear out the output jack if I plug and unplug the jack frequently. Since the DF can not be disassembled with screws to replace the jack, Is this a real concern?

 

Guys don't over think this. The DF connectors were made special just for the this reason. These are not off the shelf connectors they were specified by the AudioQuest team and are a significant upgrade.

 

Thanks

Gordon

[Wavelength]

So apologies to Gordon, our man at Head-fi found an error in his method which I'll repost:

 

MEA CULPA! (MY FAULT)

 

Hello guys.

I have to apologize for my measurment regarding the DF impedance output, yes I was wrong .

I've been reading a lot over the past days and today I discovered that my methodology was not 100% correct. Gonna explain. I was measuring the open circuit at its maximum Rms voltage and then loading it using a selected resistence. Here lies the problem, this works for amplifiers that are designed to be loaded using a specific impedance (lets say 8 Ohms). Heaphone amplifiers are designed to work in a impedance range.. see the problem?

 

So, lets for example use the JH16 pro specs to recalculate the DF output impedance:

Imput sensitivity: 118dB/1mW

Impedance: 18 Ohms

 

Using 110dB (really loud) as my reference @ 1KHz 0dBfs, I would need about 0.4Vrms to drive the JH16pro at 110dB levels. This math is accomplished by: Vrms = Antilog ( ( "how loud" – "imput sensitivity") / 20 )

 

So, I got the DF and adjusted its volume to about 0.404 Vrms in open circuit, and loaded it using a 17.9R, and as result got 0.400 Vrms.

Here is the math:

 

Zsource = Rload x ((Vo/Vl)-1)

Using the values I got 0.18 Ohms

 

Yes, thats correct 0.18 Ohms !

 

I repeated the same process for all the amps I had laying around, and Ive got almost the same measurement as stated in the specs.

 

So, if it not sounds good using high-sens. iems/ low impedance, it must be for another reason than output impedance.

 

Brandall,

 

I appreciate the response but this is still not the correct impedance or method for calculating the output impedance. As I stated above the output impedance is 0.8 ohms max (Prism dScope III) . John Atkinson tested this as well and came up with 0.65 ohms (AP27xx).

 

While there are methods to test the impedance using a DVM at one frequency, the above method is not correct, nor is your original one for tube amps. So the value you calculated at 0.18 is NOT correct.

 

Also do note that headphones do not load at the same frequencies anyways. So really folks, best bet is try it and see because this is all about taste and with headphones it's more so than with full systems.

 

Thanks

Gordon

[Wavelength]

I used the volume in Amarra Junior to vary the volume and didn't hear anything untoward.

 

BTW, it's got ample power to drive LCD-3s as loud as you'd ever want them.

 

Guys lets use some names... I hate answering directed posts to aliases.

 

You would be far better off to use the System Wide volume control which works in the analog domain. The Amara as well as other applications that don't effect the System Wide Volume control will be doing this in the digital domain which won't sound as good.

 

Correct, the DF volume control does not take effect in applications unless specifically stated that it is going to the hardware or system wide volume control.

 

Thanks

Gordon

[Wavelength]

Gang,

 

Let's clear up a few things....

 

Vista:

 

Really I have no idea why this is happening the Proton has exactly the same code and works fine. Microsoft is deep into Win8 so getting them to look at this is hard enough. Do note that we discovered for them that their async code for class 1 was wrong so hopefully that will be fixed. I asked about 88.2 in the control panel... AGAIN and who knows what will happen.

 

Volume Control:

 

Always use the hardware volume control inside the DragonFly for any adjustments. Yes AgentSmith (Guys how about some names!!!!) some applications like Decibel and Pure Music that take over the hardware device like the DragonFly will present the application volume control as it is linked to the system volume control and therefore is correct.

 

Thanks

Gordon