HD 650 made in 2013.
Setups I have tried HD 650 with
DIY Dac -> Beta22 3ch upgraded -> HD 650
DIY Dac -> Project Ember -> HD 650
Asus STX -> HD 650
Asus STX DAC -> Project Ember -> HD 650
Project Ember Settings
Input Capacitors Bypassed
Low Output Resistance
Tubes tried with Project Ember
RCA 12AT7 Black Plates NOS
Siemens 6922 NOS
RCA ClearTop 12AU7
Other Headphones I have listened to
Pioneer SE A1000
Other Amps I have listened to
Other DACs I have listened to
DIY dac Ad Labs
Brief Impressions of HD 650
It is a dark sounding, smooth, laid back yet high resolution headphone which is engaging enough to listen to hours at a time while being mid centric with a mid bass hump. The deep, tall and engaging soundstage is a good point as well.
5 - Excellent / Very Good
4 - Decent for the price/taste/sound signature
3 - Passable for the price/taste/sound signature
2 - Not acceptable for most
1- Horrible, deal breaker
Lush, crisp, slightly forward, reasonably articulate.
Really lush and sweet unless you try off the STX amp of course. Crisp with the Ember while being rich.
Bass Quantity 4
Needs heavy amping to get the right amount of bass. With a certain tube on Ember it is 4.5 and with Beta22 it is 5. Mid-fi amps don't do full justice but ensure an enjoyable experience.
Bass Quality 5
Ember and Beta22 both do a good job in getting out quality, tight bass.
There is less treble than what a neutral setup should have. However, it is acceptable considering LCD2 off Beta22 was worse as in darker! HD 598 is better in this respect but doesn't sound better overall.
Tonal Balance 3.5
I prefer the tonal balance of RS 180 as my perfect tonal balance, but the HD 650 is superior in all respects and I don't really miss the RS 180 too much though I still own it :) The sub bass is a bit less, mid bass needs heavy amping, and the headphone is dark instead of neutral like HD 600.
Soundstage Width 3
As we all know at this price, most other headphones have better soundstage width.
Soundstage Height 5
Better than the width. Better than the HD 598 I think.
Soundstage Depth 5
Much better than any other headphone I have tried except HD 800.
Soundstage Overall 4.5
Pretty nice for a yesteryear flagship.
Good, perhaps not as good as K702, not fully sure, but reasonably good, no issues here.
Comfortable for long hours after the initial opening up of the headphone.
Not sharp like a K702 but definitely better than HD 598.
Articulate enough for the price. Not as good as LCD2 but that is twice the price. HD 800 is a definite step up though.
Very engaging to listen to hours on an end.
The So Called Veil
I didn't find it on the Beta22 at all. On Ember I sometimes feel it, sometimes I don't. It is pretty good with Ember, though perhaps zero veil at all times, though. Not a deal breaker though. However, with a preamp phono with headphone out it did have a veil. So it does need heavy amping. Anything less than $200-500 on the amp and you will probably feel veil, and even then it won't disappear completely.
However, with Project Ember it is enjoyable and very often there is no veil.
With RCA Black Plates 12AT7 it is darker, so the veil seems more present. With brighter tubes like Telefunken 12AU7 or brighter still RCA Clear Top 12AU7, the veil is less present and the tonal balance is more neutral. On the other hand, it sounded the warmest/darkest with the Beta22 but with no trace of the veil.
I recommend a bright amp with the HD 650 or a ultra high end neutral Amp. So if you choose a tube amp make sure that it uses a bright tube.
Low Volume Listening
Not ideal for low volume listening, especially because of the slight veil and HD 650 nature. However, moderate and loud volumes are very enjoyable. However, when I say moderate, that is probably low for most people. So this isn't a deal breaker for anybody, trust me. You will be fine! :)
It is an all rounder headphone though some people may not like it because of its dark nature. However, with the right amping, most people will get used to it. It definitely scales very well with an amp.