Massdrop Sennheiser HD-6xx (aka. HD-650) $199

Thanks. Having read quite a few threads in multiple forums as well as a number of reviews, and not having had the opportunity yet to audition, indecision is most certainly where I’ve arrived at. It’s further complicated by the fact that in the discussion for just about any of the more popular options there’s at least a few people that mention they use it with their HD-6XX and are happy with it. I’ve thought about going to the CanJam in NYC (which is a day trip for me) in February to try to get my bearings better.

 

The THX AAA 789 is indeed a great amp, but I haven’t heard it with the 6xx. On a completely different note, I picked up a Darkvoice 336se tube amp lately and couldn’t be happier. It solves all the reservations I had about the 6xx: that it was dull, muffled and a little uneciting (but with great tonality). The Darkvoice really brings some life and verve to the Sennheisers!

 

I’ll second that last bit! I don’t know any area of audio where there’s more disagreement about even the basics than headphones and amps. Reviews and opinions can point you to things to try, but you’ll end up going in circles until you try out the equipment for yourself.

 

I bought one about a month ago. It sounds wonderful. People say it has just a touch of tube sweetness; I would say it’s very accurate and realistic-sounding, without any evident fake warmth distortion from the tube (which I think regulates the voltage on the input end). I’m extremely happy with the pairing with the HD6XX. I’ve not heard drum kits sound more realistic than this. The DAC is very good too.

Enjoy this thread:
Massdrop x Alex Cavalli Tube Hybrid Amp (CTH) - Dropping Monday

 

The link above goes directly to page 67, unfortunately. The thread begins with speculation about the new amp, and then people start receiving and reviewing them from Massdrop in the mid-teen pages. The amp and phones do require substantial burn-in.

Listening to the stereo mix of the Beach Boys’ Summer Days album on them now— whoa. Unbelievable clarity and seperation without any etched quality whatsoever. A huge, natural soundstage.

 

Thanks again! It sounds intriguing. I don't need the DAC, so I guess I'll have to wait longer until the DAC-less version comes up.

 

Hey, Action pact, I was reading about the Nobsound this morning and saw that the latest version on Amazon doesn't use the 6J9 tube but the 6J3. What version did you get and from where?

 

I bought mine from doukmall on eBay, and it has the 6J9's.
Nobsound Audio Mini Vacuum Tube Headphone Amplifier Stereo HiFi Earphone Amp New 372040340119 | eBay

 

F it. I am getting one. All the info for tube and op amp rolling is for the 6J9 model, so that's the one I want. If I end up listening to my cans all the time, I'll upgrade then. Thanks!

 

Yes, it's both interesting and challenging to sort through it all. I'm looking forward to being able to try some things out. For the time being I ordered a JDS Labs Atom AMP which has gotten a lot of praise as a budget option. At $99 I figured it's a low-risk way to get started and give me time to investigate better options. Then I can always sell it or use it in another room later. Ultimately I'd like to end up with two setups - something for the desktop computer in my home office, and then I have a comfy leather chair in another other room where I'd like to set up a listening station.

 

Going to a meet is the best way to get your bearings in this hobby/journey. Going to a big meet like a CanJam is even better because such a wide variety of gear and vendors will show up. Smaller local meets are also helpful, but since the variety and breadth of gear that shows up is more limited you will need to go to many of those meets to hear a variety of gear and systems.

I have a little saying that 3 minutes of listening to a headphone or amp at a meet is more helpful and more valuable than spending 3 months following every post and review in a head-fi thread about that headphone or amp.

Once you hear some of the popular headphones and amps you will be able to better relate to reviews. And better be able to weed out the reviews that are useless or plain wrong.

 

I've had the HD-6XX's for a about a week now, and have had maybe an hour a day with them, so they're still probably opening up. I haven't yet received the new tubes for the Nobsound, but I'm enjoying these headphones quite a bit.

Some observations:

• They're warm/smooth but not slow, dull or rolled off.
• The top end is present and clear, but not exaggerated; it's delicate. I can understand why in some systems it coud be perceived as veiled. I happen to like their presentation.
• Bass extension is better than I was expected. No disappointment with the low end heft.
Imaging is spacious, extending beyond my head. I was actually startled a few times, thinking a sound came from within my room.

 

My 2 month in observations:

Running the HD-6XX in my home office — driven by a Bottlehead Crack w/ Speedball upgrade. Tunes are coming via Spotify premium through an HRT Music Streamer II+ DAC.

I can't say enough good things about this setup...after swapping back and forth with my portable headphone setup (MassDrop Nuforce EDC3 + Audioquest Dragonfly Black) it's apparent how much more information and how much more even the Sennheisers are across the whole audio range. Great bass, outstanding mids, and a nice top end - yes, it's not quite as 'bright' as the IEMs, but I like it much better. For me, the sound signature is about perfect - it's pretty similar to my main system setup (Primaluna Prologue EL34 integrated + Harbeth C7 speakers)...slightly on the warmer side of neutral, wonderful midrange, detailed but super musical. It's just really, really honest. I am kicking Neurosis "Times of Grace" right now and it sounds like I'm sitting in the Electrical Audio space with them while they record it.

Great sound stage — as action pact mentioned above, more than once over these past months, I've turned around thinking my wife had opened the office door and was doing something in the room, only to realize the sound was coming from the headphones.

The Bottlehead amp seems like a great match for the 'phones, I can see why the two are often recommended together. I did pick up some cheap NOS tubes off ebay to swap in - an RCA Clear top 12ax7 and an RCA JAN 6as7g. Noticeable improvement over what was in there when I bought it off eBay.

Only wondering what a better DAC would do. Keeping an eye on the used market for an older MHDT to try, have read great things and based on the descriptions sounds like the sound signature I'd dig.

If you're on the fence about these, just pick them up, you won't be disappointed.

 

So I'm curious to know if my thinking is correct...

...a solid state (Class A) amp would make the HD 6XX (650) sound more analytical and scale back the warmth down a touch?
...a tube amp would make the HD 6XX (650) sound more warm than it already does?

 

Back to report EXCELLENT customer service from Sennheiser on this. Unit replaced....about 10 day total from my shipping to receiving replacement.

 

In the case of vast generalizations - yes this is correct. Amp pairing doesn't always line up with generalizations or even perfect spec alignment, but this is the accepted generalizations of solid state vs tube. The actual outcome with be case by case.

 

I’ve had the HD 6XX for about a month now. I love them! I prefer them to the HD 598, but not by much.

 

What are you using for the headphone amp? The quality of the headphone amp makes an important difference in how much the HD6xx will pull ahead of the HD59x series headphones. With a very good amp the HD6xx will be well ahead of the HD598.

 

Just the headphone jack on my stereo receiver, and a FiiO (?) portable headphone amp. Far, far from anything fantastic.

 

When you get a chance to try the HD6xx with a better amp you're in for a treat.

I find the HD6xx and HD59x headphones to be pretty close in preference when driven by something like a laptop. But once the HD6xx gets a good amp it pulls ahead while the HD59x hits a performance plateau and stays in the rear view mirror of the HD6xx.

 

That’s what I’ve heard! I’m hoping to get a good headphone amp soon.

 

A few weeks later, and the HD-6XX's are continuing to open up and improve. The above assessment still holds, but there's more of everything good now.

As an aside, I received the upgraded '60s USSR tubes for the Nobsound hybrid amp a week or so ago, and that was a noticeable upgrade. The tonal character became a lot more, uh, natural and uncolored, and imaging became a lot more 3D. For a little over $50 including the tube upgrade, these little amps offer a lot of value; no wonder the folks on headfi.org gave it a thumbs up. This amp will satisfy for a while until I'm ready for an upgrade.

 

Dumb question, but where does one acquire this amp and upgraded tubes? They sound great. Very interested.

 

Here's the amp:
Nobsound Audio Mini Vacuum Tube Headphone Amplifier Stereo HiFi Earphone Amp New 372040340119 | eBay

There are lots of eBay sellers in eastern Europe offering Soviet military 6J9 tubes for not much money:
6j9 tube | eBay

These are the tubes I bought:

 

Thanks!