They’re identical with the exception of the padding on the head band which doesnt really factor too much because the clamp is more essential for fitment
Also @joshua_g based on your tastes I think youd really enjoy the 58x 
I havent tried eq on the 600/650/6xx but the consensus seems to be it’s not ideal on these so I’d caution @Poi400i in that regard
Yeah, I like to know every bit of detail about everything. At least everything that interests me, like most audio related stuff.
I’m aware of that. The HD600 is available on the Sennheiser official site here in Brazil, but it is out of stock, I think exactly because of this change. Anyways I’m one of the people that found the new design more appealing in the end. I didn’t really like that old look. And I kind of care a lot for looks because I want to have a big and beautiful, unique collection, lol
That’s exactly how I feel. Nothing like months of research and still not being able to make a decision. That sucks. But in the end I think I might go with the 600 because of what I said before, plus I will be buying the AKG K371 that sound similar to 650’s. And since I listen to a lot of jazz the brighter signature of the 600 might be better for that than 650’s. They are also cheaper here in Brazil.
Even with all those factors I’m not exactly sure about my decision haha. And we’re o live I can’t audition absolutely anything. I think I will just have to buy it and see. But since I will buy the K371 first, maybe I can see if I like that signature more or not.
So… I have another question for you M0N. Do you think owning the Sundara and the DT1990 make any sense? Or are they too similar?
Because the Sundara is another available option here (not to replace anything, just adding to the collection)
I am curious to test this theory! 
I think if you like the sound signature of the 1990 but want something smoother and less harsh (but still bright) and the sound of planar they make sense imo
I have had the HD600’s for several years, and lots of other cans much more expensive…most of them have come and gone but the 600’s are still here…
They work wonderfully with a OTL tube amp like a Schiit Vahalla 2 or a Bottlehead Crack…dont know if you can get these where you are…
I cant state how well these work with these amps…or a really nice tube amp…
Alex
Well, I own a Little Bear P7. It’s not a hybrid, so I think it is OTL?
I think it uses Chinese tubes, Soo… Not the best, but they are pretty good with my DT1990. I think it may be good with the 600 aswell
As far a I can tell this amp is NOT an OTL amp, the circuit is a 1940’s SRPP design Series Regulated Push Pull design that runs in Class A…so its “HOT”…and they state to turn in off at 2 hours to give it a rest?? I would not buy an amp that states this???
Does this mean the designer of this amp is telling you something?? For the low cost its a great tempting purchase…but I would go the route of a $99 Schiit Magni 3+ or the Vali route if you really want a tube amp…
Alex
I thought SSRP was for Series Regulated Push Pull?
Yes!! My bad, mind is still reeling from a visit to the grocery store this morning!!
Series Push Pull, unregulated food fight!! Omg!!
Its crazy out there!!
Common Sense!
:>)
Alex
Also what do you think about the little dot mk2 since it’s a cheaper tube amp and you have experience with lots of tubes? I thought it was solid for the price if your on a budget imo
I never have had any LIttle Dot’s, they have been around for a long time and have quite a lineage…many of them out there and they have a pretty good track record so for an entry level tube amp they look ok IMO. (In the beginning of my headphone journey I was tempted to buy a l’dot, but when the LYR route, Vahalla 2 route, BH Crack route, BH Mainline Route, ECP T4, Hagerman Tuba etc…)
But from what I read its not the greatest below 100 ohms…having gone thru this many times buying an amp that works only wil hi or low impedance cans can double you eventual cost as you buy more cans with hi and low Z…
Some exceptions IMO are the BH Crack which ofr cans over 120 ohms like the 250 and 600 Beyers and Senns…are made for these cans and have an excellent track record and stellar results…but again they Low Z stuff is left hanging out…if you can afford this great is not then its a concern for sure.
The main issue I have with the Little Dot and all these low cost imports is quality of parts and construction. Many folks have no issues, and many do…take a look at the reports over at the Drop for the Little Dot Mk2…not the greatest.
Guess what I am saying is getting into this hobby, a decent tube amp is just going to cost abit more than a SS amp…and there are SS amps that sound “tubey” and work with hi and low Z cans…but at a slightly higher price…
Alex
Vali is only $149! 2 yr warranty!! and if it breaks u dont have to deal with overseas etc.
Yeah, I personally would only suggest a tube in the budget area if you have a headphone that takes exceptionally well to a tube, otherwise imo you can get a much higher quality solid state for similar or less cost than a budget otl. Although I’m not a fan of the cheaper tube hybrids as they don’t sound that great to me
Couldnt agree more!
Have you gotten to hear a monolith liquid spark? That’s a warmer toned solid state for a great price (that imo will accomplish what people want out of a cheap tube hybrid but more refined)
Uh… Understood. I am quite new to this tube world, so I don’t really know what an OTL Tube is. Is the darkvoice 336SE OTL?
I thought OTL were just the Non hybrid tubes. Would you mind to explain just a little bit? Haha
Nope havent heard this one either…for $99 its a steal for sure…
The Schiit Magni 3+ is quieter and produces more power than Liquid Spark.
IMO, you may get one of these and it works great forever, but IMO today a Vali ($149) or a Magni 3+ for $99 and a w yr warranty is a no brainer…
Some folks at the Drop dont think this amp is indeed a tube like amp…as often in this hobby it boils down to your ears at home with your headphones…
The good thing here is if you buy a $99 amp from Drop you can at least return it!
Alex
The liquid spark is tuned differently than the magni 3+, but the magni 3+ is also great
I would suggest you do some reading online…many places that describe what a OTL is and is not.
OTL = Output transformer less…
The other major type is a NON - OTL = Has output transformers…
The latter usually costs more…and works with a wider range of headphone impedances…
Hybrid amps usually have both SS and tubes in the overall design and how this is done is rocket sciene for this discussion…to really get this you need to go to school or have the ability to read or look at circuit diagrams and schematics…not easy to do unless you have some electronics or circuit theory classes under your belt.
People will from a simple explanation paint with broad strokes oh how these different designs work and sound…many, many opinions…
In the end your going to get what you pay for, but recently the cost of some really good stuff has dropped dramatically in price…some from Schitt ( yes I a Fanboy here)…but other folks like JDS Labs has good low cost offereing as well…
So do some googling and start reading and learning,its an amazing hobby!
ALex