[wuyuaza]

First of all, thanks for coming in to help.
I read that audioquest's dragonfly red is a dac+amplifier. So does that mean I have to connect headphones to it but not amplifiers?
Trying to find an easy solution for pchifi. I would mostly appreciate it if anyone has an answer for the dragonfly thing or a better solution. I am using stax sr407 with srm-006ts.

 

[ProtegeManiac]

Consult the manual. If it has a "line out" mode then check how to activate that. AFAIK the Black has it. If you don't hear any noise then no problem, although AFAIK all the Red has is that it's got low enough noise that yo ucan use its headphone output as a preamp so your next problem is to figure out how to get 2V only, without noise, and then use the volume control on the amp.

If you haven't bought it yet and you already have an amp you have tons of choices that will be easier to use as a DAC than that. Like the Schiit Modi3. Or any DAC from JDS Labs.

 

[megabigeye]

Yes, Dragonfly Red can be connected to a separate amp. Just turn its volume all the way up and it enters DAC-only mode. Per the Dragonfly spec sheet:

When used as a line-level device (volume set to 100%), DF Red's 2.1 volts provide enough power to drive all preamplifier, integrated amplifier, or receiver inputs.

I use it that way and it sounds good.

 

[bzippy]

Yes, Dragonfly Red can be connected to a separate amp. Just turn its volume all the way up and it enters DAC-only mode. Per the Dragonfly spec sheet:


I use it that way and it sounds good.

As far as I know most USB DAC's work that way. I have three from HiFimeDIY that I keep in my car, bedroom and living room for use with my phone or laptop. Don't know what source you're using but they make a number of nice USB DAC's that even come with different pre-made connectors, such that you may not need a separate OTG cable when using an Android device (USB micro, USB C, etc.).

Also I should mention that with my HiFimeDIY DACs the line level output (highest phone volume) can be too hot for some of my amps (specifically my car stereo and portable speaker's aux inputs), and it distorts. This happens most often when running the music player app on my phone (with local music files), but it doesn't usually happen when streaming Spotify, which seems to be lower level for some reason. Anyway I usually reduce my phone's volume by one step in my car and when using my portable speaker to avoid this distortion. What I don't know is whether this kicks in the DAC's headphone amp mode. I'm guessing it does, but neither of these two problem systems are high end by any stretch so I'm not worried about any loss of quality that might come from double amping.

None of my higher quality amps exhibit this distortion issue when fed by my HiFimeDIY USB DACs. They all sound great!

Last point: I get the same distortion issue on those two cheap systems when feeding them with the line out of my FiiO X3 dap. So it's not like my USB DAC's are putting out an usually high line level or anything. I don't know if there is even such a thing as different line levels -- standardized maybe??

 

[FlavioWolff]

Yes, Dragonfly Red can be connected to a separate amp. Just turn its volume all the way up and it enters DAC-only mode. Per the Dragonfly spec sheet:


I use it that way and it sounds good.

There is no such thing as a "dac only" mode. It still uses the amp section. The same amp section that would be used otherwise. But the max voltage is around the same as a fixed line out (2v), so it won't matter much for the external amp. The output impedance is different from a regular line out, but it doesn't make much of a difference, it seems (i'd like more knowledge on this matter).

 

[megabigeye]

There is no such thing as a "dac only" mode. It still uses the amp section. The same amp section that would be used otherwise. But the max voltage is around the same as a fixed line out (2v), so it won't matter much for the external amp. The output impedance is different from a regular line out, but it doesn't make much of a difference, it seems (i'd like more knowledge on this matter).

You're right. I should have said "line-out mode" or something similar. The DFR does not bypass the amp section, but provides a constant 2.1V at max volume. It was a while ago, so I don't quite remember, but I probably meant that in "DAC only" mode you're not using it connected to headphones, but connected to another amplifier. Or maybe I was just being stupid.
As far as output impedance, as far as I understand it shouldn't matter since many (most? All?) amplifiers' input impedance is close to 10K Ohms.

 

[FlavioWolff]

You're right. I should have said "line-out mode" or something similar. The DFR does not bypass the amp section, but provides a constant 2.1V at max volume. It was a while ago, so I don't quite remember, but I probably meant that in "DAC only" mode you're not using it connected to headphones, but connected to another amplifier. Or maybe I was just being stupid.
As far as output impedance, as far as I understand it shouldn't matter since many (most? All?) amplifiers' input impedance is close to 10K Ohms.

I would love to read some clarification on what would differ between, say, 1 ohm output impedance (headphone amp) vs 400 ohm output impedance (common line outs) when driving a separate amp. I can't find anything by googling (maybe I suck at googling).

I know both sound fine, but I'm still curious

 

[megabigeye]

There is an amp impedance thread in the Sound Science forum. You could probably ask there, or start a new thread if that thread doesn't seem appropriate.

 

[GoodEnoughGear]

I would love to read some clarification on what would differ between, say, 1 ohm output impedance (headphone amp) vs 400 ohm output impedance (common line outs) when driving a separate amp. I can't find anything by googling (maybe I suck at googling).

I know both sound fine, but I'm still curious

You want your input impedance on the target amp to be at least 10x (as a general rule) greater than the output impedance of the source. Therefor a low ZOut will generally assist in making sure you don't get impedance mismatches. Some amps (tube amps in particular) can have quite a low ZIn, as low as 600 Ohms which requires the source to have a high-current capability - not sure if the Dragonfly even with an OI of 1 Ohm would be able to not get the voltage drawn down by such an amp.

 

[FlavioWolff]

You want your input impedance on the target amp to be at least 10x (as a general rule) greater than the output impedance of the source. Therefor a low ZOut will generally assist in making sure you don't get impedance mismatches. Some amps (tube amps in particular) can have quite a low ZIn, as low as 600 Ohms which requires the source to have a high-current capability - not sure if the Dragonfly even with an OI of 1 Ohm would be able to not get the voltage drawn down by such an amp.

So, if I got it right, what is important is having an impedance ratio above 10x not having the load impedance too low as to draw too much current from the source?

So, in the case of a 25k input impedance amp (like the schiit magni 3+), all things being equal, there is no concerneable difference between driving it with a headphone amp delivering 2v/1 ohm output impedance and a line out delivering 2v/400ohm output impedance?

So, "double amping" (connecting headphone amp outs to line inputs) is not such a big deal at all

(edit: sorry for the three " so's ")

 

[GoodEnoughGear]

So, if I got it right, what is important is having an impedance ratio above 10x not having the load impedance too low as to draw too much current from the source?

So, in the case of a 25k input impedance amp (like the schiit magni 3+), all things being equal, there is no concerneable difference between driving it with a headphone amp delivering 2v/1 ohm output impedance and a line out delivering 2v/400ohm output impedance?

So, "double amping" (connecting headphone amp outs to line inputs) is not such a big deal at all

(edit: sorry for the three " so's ")

Yup, you got it. Also the issue in general with "double amping" is getting too hot a signal for the load - generally consumer gear is looking for 2 volts or less single ended and 4 volts balanced (Pro gear can range up to 14 volts or even more). Double-amping can result in the load clipping if voltage is too high.

And of course generally the less stuff a signal goes through the better.

 

[steady339]

I’m using my Dragonfly Red with a wired line connection to drive two JBL Xtremes. iTunes EQ set to reduced bass and mac utility program MIDI/setup set for 96k playback. The Xtremes run as powered monitors. Sounds very good and better and more satisfying sound from the Xtremes than with Bluetooth. No joke, makes the Xtremes sound like hi-fi speakers!

 

[Bassic Needs]

Old thread but related question: the Dragonfly Red outputs 2.1v and I want to use 3.5mm to RCA L/R converter cable and connect it to a Monoprice Monolith 7x 200W speaker amp's L & R RCA inputs to drive some speakers. The Monoprice manual says:

Input Sensitivity for Full Rated Power
RCA Input: 1.49 Volts
XLR Input: 1.67 Volts

Is it ok to connect the 2.1v DF Red at full volume or should I try to keep it at 75% or less?

 

[HiFiHawaii808]

Yes, Dragonfly Red can be connected to a separate amp. Just turn its volume all the way up and it enters DAC-only mode. Per the Dragonfly spec sheet:


I use it that way and it sounds good.

I tried it and it sounded horrible. Maybe I didn't have the volume set high enough on my PC or maybe the cheap cable I got from Amazon was the problem.

 

[megabigeye]

I tried it and it sounded horrible. Maybe I didn't have the volume set high enough on my PC or maybe the cheap cable I got from Amazon was the problem.

Hmm. Too bad. My DFR no longer works so I can't go back and figure out why it would sound bad. I used to use it this way semi-frequently and I always thought it sounded pretty good.
Or maybe your standards are just higher than mine!