[Arniesb]

Sorry, didn't mean to say that the A20 was bad or anything, but if you ask for an amp for the HD-650 on this thread most would suggest a tube OTL amp due to better synergy with the HD-650, many would say that the HD-650 and BH Crack were made for each other.  A benefit of tube amps is you can tune the sound by using different tubes.  The BH Crack is not veiled, bassy or slow, but this is also something that your choice of tubes will affect.
I didn't only try the HD-650 with the BH Crack but with other amps such as Asgard2, Lyr2, Project Ember, UD-301 headphone output, Magni, WA7d, Gustard H-10, and a few others that I can't remember, still the BH Crack was the best pairing with the HD-650, HD-800, T1 and DT-990 premium 250ohm for an amp under $500, maybe even under $1000.
As for the sound from the BH Crack, its clear, dynamic and full, tames the some times harsh highs of T1 and HD-800, depending on tubes used the bass extends low and is never muddy, mids are smooth and full.

I don't have skills to build crack, and if i dont like A20 with other cans i then whould buy other amp. And doesn't A20 and crack supposed to have similar sound?

 

[DavidA]

I don't have skills to build crack, and if i dont like A20 with other cans i then whould buy other amp. And doesn't A20 and crack supposed to have similar sound?

I never got to use the A20 so I can't say that it would sound like the BH Crack, also haven't seen it mentioned much on the threads that I follow.
As for building the BH Crack its actually a lot easier that I was expecting, took me a night to build, about 8-9 hours of actual work time but I was drinking wine and talking with my GF when I was building it so it took from 4pm to 7am.  If you really don't want to build then there are many for sale in the "for sale" thread, many are custom job and look really nice. 

 

[Music Path]

  Back in the day it used to be the norm to partner warm sounding components with colder sounding ones in an attempt to achieve some neutrality. Since I bought my HD 650's this has went out the window and the only thing that works for me are tube amps. Why? No idea. In theory, a warm headphone paired with a warm amp (which the vast majority of tube designs are) should result in an overly warm, dark tonality. It just doesn't seem to work out like that with the HD 650.

I read that tubes create distortions in the music which usally makes the music sound better. The reason is unknown though. That may explain in part why tubes are still popular today.

 

[Youth]

I prefer hybrids over tubes. Anyone in here heard the Liquid Glass? 

 

[gefski]

I read that tubes create distortions in the music which usally makes the music sound better. The reason is unknown though. That may explain in part why tubes are still popular today.

Tubes, transistors, chips, all circuits damage the music signal. Some distortions may be less offensive to the ear/brain than others. Lots of ink has been spilled on even vs. odd order harmonic distortion, for example.

 

[ButtUglyJeff]

  I prefer hybrids over tubes. Anyone in here heard the Liquid Glass? 

 
Mother of all tube hybrids....

 

[Franklin]

Is there any good replacement earpads that will fit my HD650, other than official ones from Sennheiser?

My ears always brush up against the foam covers over the drivers. It's only slightly annoying and I can usually fidget with the fit a bit to make it go away.

Brainwavz HM5 earpads, using mounting rings from old hd600/650 earpads.

http://www.head-fi.org/t/197776/sennheiser-hd650-impressions-thread/18045#post_10652370

 

[Music Path]

  I prefer hybrids over tubes. Anyone in here heard the Liquid Glass? 

A hybrid has the same effect of the tube amps. You simply have the advantages of the SS to. You combine the best of the two worlds, solid state and tubes.

 

[penmarker]

Tube buffered SS amp? You do get the tube flavour, but not the voltage swing.

 

[Music Path]

Tube buffered SS amp? You do get the tube flavour, but not the voltage swing.

Yeah i know it is not quite the same. But in my statement i was referring more about having the tube flavour too. The other reason is that one might prefer hybrids over tubes, but hybrids still imply the need of using tubes. I mean in the case you don´t like tube rolling. 
 

 

[penmarker]

I got a tube buffered dac Aune T1 and I love it very much. Though it only runs on a single tube instead of a matched pair. Tube rolling works very well, I got 3 different tubes with distinct sound signatures.

Though I do believe whether an amp is slow/fast, warm/cold, bright/dark, or distorted/clean depends on the implementation itself, not the type.

 

[smy1]

is there a huge difference between the 650 and the fidelo x1 i may be planning to upgrade my fidelo in the future and my only amp is the nx1. Can the nx1 even power the 650 at all?

 

[DavidA]

  is there a huge difference between the 650 and the fidelo x1 i may be planning to upgrade my fidelo in the future and my only amp is the nx1. Can the nx1 even power the 650 at all?

They is a noticeable difference between the HD-650 and Fidelio X1, the HD-650 is a little brighter, the X1 has more bass but its not as tight as the HD-650, and mids are much smoother on the HD-650.
As for your question with the NX1 driving the HD-650 I don't know, but the HD-650 is much harder to drive properly than the X1.  The X1 will sound good out of a phone or DAP while the HD-650 sounds better the higher up the ladder you go with the source and amp.  Hopefully some one else can chime in on the NX1 amp.

 

[retskrad]

What the hell, Is there a headphone out there that has the same good mids and vocals as the hd650, but has better bass and not so much treble?

I feel like the hd650 does the best with vocals, it's so smooth and not artificial, unfortunately the bass is quite bad.

 

[Sal1950]

 unfortunately the bass is quite bad.

That's a pretty harsh statement that I find totally undeserved. They may not have the best bass available, but quite bad?  IMHO I'd call it quite good.