Headphone DAC/amp question

I have been a lifetime subscriber and happy roon user for some months now. I have moved away from my large CD collection to buying a NUC 8i3, a DigiOne Player, a Music Fidelity v-90 Dac that feeds into my old Denon amp (PMA 425r) and (old) Dynaudio Audience speakers. iPhone serves as the remote. Happy with this setup and the sound quality.

Now I bought Sennheiser HD 650 headphones, as I thought I could even enhance the SQ. My Denon amp has a headphones line-out, which I use. However, so far I am rather dissapointed by the sound of the headphones, I rather prefer the speakers. When I plug the headphones into my Dell XPS laptop, which I also use as a remote, the sound is pretty similar. I expected better seperation in the instruments, and piano sometimes sounds harsh.

My question:
Is SQ in my chain mainly deternined by the DAC, which I consider pretty decent? Or could the SQ be influenced negatively by the Denon Amp and the line out?

Should I consider a different Dac with a headphones line-out, which the the V-90 does not have? Do you have any recommendations?

Or should I rather consider a mobile solutions, such as a Dragonfly red/cobalt, Topping DX4 that I could plug into my iPhone? I considered this, but am not a big fan because of all the adapters etc.

Thanks for your advice.

Room, Amp, Speakers, Source/Mastering, DAC. That is the order of importance to SQ in my opinion. Speakers or Headphones, although Room doesn’t matter for Headphones.

So I should change the amp? All my music is in flac, so there should not be a problem there.

The amp is about 15 years old and was probably not more than 200€ at the time.

But does it really negatively affect SQ in my setup?

Add a headphone amp. Your Integrated AMP headphone amp is probably underpowered. Some inexpensive options can be found on Massdrop (drop.com). Depending on your budget, you could make a big jump for not a lot of money. Also check Schiit.com for factory direct options.

If you like the sound signature, the headphone amp would be a cost effective solution to address the headphones. Integrated AMP/AVR headphone amps tend to be an afterthought.


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I can’t answer about your setup.

But, yes, the amp is very determinant for how a speaker or headphones sound. Also, the section of the AMP that drives the speakers may not even be the same that drives the headphones.

Did you demo these cans with any particular headphone DAC/amp?

If so and you liked it enough to buy these cans, maybe get that same headphone DAC/amp?

Like many/most, I’ve made the mistake of buying based on online reviews… nothing beats a proper demo.

Home demo is ideal but even if you can’t do a home demo then a store demo is better than no demo.

If you didn’t demo the headphones, it may not be the Denon - it may be the headphones that don’t suit your personal taste/preference, even though they are well regarded in terms of reviews.

Would agree as I own a pair of HD650s and they need a lot of driving and are very neutral sounding hence why I only listen to vinyl with them. For Digital sources I have a pair of Sennheiser HD 598 Cs Around-Ear Closed Back Headphones which are much easier to drive and sound good " To me at least ".

Interesting that you place amp before speakers given the general belief is it’s the other way around. Colour me intrigued :slightly_smiling_face:

Thanks a lot for all the replies. That does not make it any easier;)
I may have to buy a headphone DAC/Amp. I am thinking about the topping DX3 Pro.

EDit: Massdrop and Schiit is not a good option, because I live in Europe.

Edit 2: And no, I didn’t demo the headphones, unfortunately. I went only by online reviews, which is a stupid thing to do. I know. It is like buying wine only by a description of words.

I agree that the amp, provided it has enough power for the speakers, belongs at the end of the line.
Room, speakers and source all belong well ahead of pre-amp and amp in order of importance.

The HD-650 are not easy to drive but sound wonderful with the proper amp. The headphone out of most receivers/amps is usually pretty bad sounding and/or underpowered (there are exceptions, such as Marantz units) and only added as an afterthought by the manufacturer. Get a dedicated headphone amp, such as the Topping you mentioned, and you will understand why the HD-650s are so highly rated. Also avoid the Pro-Ject Pre Box S2 Digital, which sounds great but does not have enough power to properly drive the HD-650s.

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Thanks for the reply. It is simply staggering how many headphone amps/dacs are out there… That does not make it easier to choose one

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Made even more difficult since you already have a decent DAC and so you need to look at both headphone amps and combination headphone amp/DACs.

Narrow your search by ability to drive to the HD-650s and then by price. You can also take a look at the recommendations for a good amp for the HD-650s over at Head-Fi

Good luck!

Can anyone share their thoughts on the (dis)advantages of a stationary or more portable headphone dac/amp?
It would be great using the headphones in different rooms. There are portable options such as the Dragonfly red/cobalt, or the Topping DX4 that I could use with my iphone.
But I am unsure if the Topping DX4 would have enough power to drive the sennheiser HD 650.

First off do you mean the Topping NX4?

Second, now you’re opening up another whole can of worms. I’m speaking from experience here since I own at least 20 sets of headphones and about 7 headphone amp/DACs, some portable and some not. Of the headphones I have high impedance over ear, such as the HD-650, low impedance over ear (commonly referred to as portable, such as the Beyerdynamic t5p, open back, closed back, Bluetooth, noise cancelling and everything in between. Plus a few sets of in ear monitors.

As far as portable amp versus a non-portable amp is concerned I suggest that you get a portable amp that works well with your iPhone and the HD-650 and leave it that for as long as you can resist scratching that upgrade itch. By the way, in case it wasn’t obvious from the above, I am always scratching that itch :laughing:

And please don’t forget to get a nice headphone stand

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My HD650 sound their best to me when driven by a Chord Mojo. (Bought here from @wakajazz :grinning:)

Hd650 (or drop hd6xx for that matter) generally need a good hp amp to drive them. The schiit Jotunheim is considered one of the better matches on headfi.

I myself am using a diy amp (dcg3) from diy-audio forum. Very pleased.

I’d also recommend you contact Sennheiser and inquire what the minimum recommended wattage is for the HD650. Then be sure to spec your purchase correctly, since the output power is different at different impedances. The HD 650 being 300 ohms.

I purchased two of the Audioquest Perch headphone stands. I really like them.

Well, it’s worth knowing that amirm on ASR uses the HD650 as a test headphone - the inexpensive JDS Labs Atom does pretty well there. I use mine with the Arcam rHead which also works well.

Ok, I narrowed it down to either JDS Atom plus Topping D10, or the Topping DX3 pro.

My next question is how to integrate the headphone amp/dac into my existing system.

Again, I have a NUC - ethernet - ALLO Digione Player - Coax - Music Fidelity V-90 Dac - Denon amp - Speakers

Would I have to buy a second Digione Player to connect my headphone dac to? Or does the Digione have several outputs?

Or could I attach the Topping DX3 Pro to my Laptop via USB?

THanks for your help

PS: The Music Fidelity Dac does only have one analogue output, just that you know.