Advice for USB Headphone Amplifiers

So I’m going to have to live without hifi system for a couple of months, and instead I’ve picked up a pair of Sennheiser HD-6XX (a variant of the HD-650 for those that don’t know).

I’d like to drive it from my phone ideally, so likely to add in a USB adapter and plug in some kind of USB DAC / Headphone amp. the likes of the Audioquest Dragonfly, Meridian Explorer etc.

Anyone out there with real world experience of one that they’d like to share?


I have a Dragonfly Cobalt that I use with my iPhone 6S Plus and Sony headphones. I use a camera adapter that plugs into the lightning port on the phone and has USB for the Dragonfly and lightning in for power to the phone. It’s a nice very portable setup and sounds great IMHO. It is limited to 24/96 and does MQA.

I also just bought a used Meridian Prime that sounds great with my headphones. I will be receiving a lightning to 3.5mm cable today to try it with input from my iPhone. The Meridian Prime does 24/192 and MQA.

EDIT: I just tried the Meridian Prime from iPhone using a lightning to 3.5 mm jack plugged into the Prime. As best as I could tell, it was an analog signal and used the iPhone DAC. I am returning the cable to Amazon.

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ODAC+Objective2. Not portable, but :+1:

Do you use Android or iOS? This makes quite a lot of difference; Android resamples music to multiples of 48kHz, so bit-perfect playback options are limited. So a DAP rather than a DAC may be a better option for you if you’re not on iOS.

If you’re not interested in MQA I’d recommend the Chord Mojo which is a great portable DAC and headphone amplifier. Works brilliantly with iOS phones (and Android using USB Audio Player PRO) with the camera adaptor and some aftermarket cables including OTG cables for Android.

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I have a Meridian Explorer², Chord Mojo (and now Poly) and a Meridian Prime HP amp and LPSU.

Explorer² = Good, the best I have had from the Explorer has been when fed by a USBridge Sig. I find you have to drive this Explorer hard otherwise I could hear distortion on low/mid frequencies.

Chord Mojo = Much better, I would say this would be your best bet when being fed by a phone. I got the Mojo on special (there are rumours of Mojo 2 in the pipeline) and later on you can add the Poly for an even better set up.

As others have said you will need the iphone to USB adapter as the Explorer will need the extra power.

Personally my favourite set up is the Prime HP amp with LPSU but I have never tried this fed by an iPhone and I don’t even know if it is possible.

Jim, analog audio isn’t present on the iPhone lightning connector, there’s a cheap mini DAC in the cable. You want a lightning to USB adapter/cable for your Meridian Prime DAC.

Thanks Mike. Whatever it is, I’m returning it to Amazon tomorrow. Playing from the iPhone lightning port to the Meridian Prime 3.5 mm input #2 didn’t sound very good and didn’t light up any of the lights.

I do have a lightning to USB camera adapter I use with my Dragonfly that works very well. I tried that with the Meridian but couldn’t get it to work. Are you saying it should if I simply plug the Meridian USB cable into it where I would normally plug in the Dragonfly? Thanks.

I’ve just tried it here, it works via the usb camera adapter and sounds great…

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And on my iPhone too… I’m using the powered adapter, and if I disconnect the power, it dies. Perhaps this is your issue @Jim_F I’m using B&W PX headphones, and it definitely sounds much better than Bluetooth - probably no surprise there.

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OK, it’s working now. It just needed the power cable plugged into the camera adapter. Thanks for your help.


Beware the impedance of your Sennheisers , 300 ohm i guess

It may limit the output , depends how loud you like

The Cobalt and Red output 2.2 v which should be enough

I ll try on my ipad later, also i find Android quieter than iOS

Have you considered bluetooth , the Sony 1000 get rave reviews

I use my Sony for this. My Sennheisers are with my Oppo 203. The camera adapter works without the power cord with my Dragonfly because it doesn’t draw much power. I guess the Meridian needs the extra power. Thanks for helping me figure this out.

Well a friend is giving me some random Chinese usb dac and headphone amp that is self powered from mains. It’s free so I’ll see how it sounds first :wink:

Hmmm… As soon as you’ll do some equalisation and volume levelling , this might not be enough anymore…

I never do either of these things.

I use Bluetooth headphones (B&W P7 and PX) everyday while commuting, and they sound pretty good, but the whole BT codex compatibility thing is a bit confusing. aptX-HD is up to 24/48Khz (I believe), but iPhones don’t support it. In my tests (pics above), an external DAC and wired headphones really sound so much better, but it’s not very portable.

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As portability isn’t a concern, and I already have the HD6xx I’ll be sticking to solutions that include them.

Will try this cheapie Chinese headphone amp
Courtesy of my friend and then perhaps upgrade as needed.

You can pick up Musical Fidelity M1’s HPA for not too much money and they have USB dac built in

My Bluetooth listening is MP3 via a cheap Samsung cellphone at the gym Hardly the most discriminating of set ups

I was looking at the Momentum 3 Sennheisers but when I auditioned they sounded awful, guess i’m Spoiled by the HD800 s at home

Hi Fi news gives the Sony HW1000 rave reviews but I have yet to hear them.

I am shortly about to move house and may have to store my good stuff temporarily hence my interest

Indeed, I’m aware of their high impedance but also high sensitivity, which helps to counter that somewhat. I theory 2v is around the right ballpark and I’ve been automatically disregarding anything that can’t do at least 2v or 40+ mW into 300ohms.

Tempted to try a chord mojo as it seems to offer a healthy load into 300

Decided I was being an idiot and that even though I can’t transport my whole Hifi… I can transport my peachtree nova 125 amp.

It has a dedicated class A valve driven headphone stage capable of throwing 150mW into 300ohms.

It also has a 24/192 usb dac that will work from my phone without needing extra power.

So, yeah, I’ll use what I have!

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