[Bigsecret]

  As I look around this thread, I see more posts about tubes and headphones than I do the Stratus.  In fact, posts (never mind, threads) about headphones on head-fi.org dominate those about amplifiers.  Even Dacs get more attention than amps.  Does anyone else find this odd, or maybe interesting?  I am at a loss to explain it....unless all amps sound the same, but headphones don't.
 
The tube posts, at least with reference to the Stratus are right-on, IMO.  But, in my experience, the rectifier makes as much, or even more, difference to the sonics than the power tubes.  Moreover, moving to a "higher grade" 5U4G type improves the sonics no matter what power tubes you are using. If I were a new buyer and wanted to spend some extra cash on tubes, I'd roll into a better rectifier, before I started to buy new power tubes.  
 
Now let me get back to headphones. If one reads a sampling of the headphone posts on this thread, one thing stands out: many flagship headphones are fussy, fussy about amplifiers and fussy about tubes. A lot of you report that. What I don't see reported very often (if at all) is how many of these flagship headphones have users tried in their systems before they settled on one that worked for them?  
 
So, I have a radical idea.  Before people go out and plunk down $1000+ plus on the best-ever headphone, why not look for headphones that a) sound good no matter what combination of tubes you use or upgrades you make to caps, resistors, etc. and b) sound better to you (not worse) with better tubes and appropriate upgrades? Basically, what I am suggesting is that this process of tube, parts, and headphones doesn't have to be entirely a random walk, with learning in-between steps.
 
The first headphone amp I owned was a Single Power MPX-3 + goodies.  It was a wonderful-sounding amp. and I only sold it to buy the Stratus.  I started with a pair of HD650s and added K701s when they came out.  No matter what combination of tubes I used on that amp, no matter how many caps and resistors I replaced,  they always sounded better.  The same was true of my Blue Circle SBH, to which I added a custom power supply, cap pack and then main unit, the sound from these amps never changed in character, but just sounded better.  I also have a headphone amp adapter from Blue Circle to use with my tube SET and PP amps (5 of them!) and had the same experience.  This was not true of the HD800 or the Audeze LCD-2, which both proved to be exceptionally fussy.  Nor was it true of the newer Hifiman headphones I tried.  They were all over the place.  
 
Recently, my beloved K701s fell apart from extended use and i snagged a used pair of K7XX headphones.  They are basically K701s with exaggerated bass and a bit wider sound-stage/channel separation.  They also are not fussy.  The same for my new HD650s.
 
Luck (good and bad) and common sense got me here.  The common sense part was not starting at the top of the headphone price ladder.  The good luck part was finding headphones that appealed to my range of sonic preferences and weren't fussy. The bad luck part was buying spending  $2500 on headphones before I was able to try them in my system for an extended period.  And there also something (a lot of something) to be said for improving the sonics at the amplifier end of the chain, before "rolling" headphones, something I learned from my bad luck experiences with the HD800s and the Audeze LDC-2.
 
In summary, to new buyers:
1.  Don't buy anything or change anything internally before you have owned the Stratus long enough to break it in and learn its sonics.
2.  If you have a pair of headphones you already love, stick with them for a while.  You'll probably love them on the Stratus.  
3.  Roll the rectifier, first (even if it costs $500-$1,000), and listen on your old headphones for sonic differences.  Hopefully, you will hear the differences, and they will be better.
4. The same holds true for changing amplifier parts.
5.  If your old headphones + tube rolling, etc. doesn't get you what you want, then beware.
6.  If ,you can't audition new headphones in your system, you may get lucky, but (again) beware of reviews.  A recent Stereophile review raved about the newest Audeze cans, but already some listeners call them fatiguing!
 
The Stratus is an excellent amplifier, stock.  

+1 - especially the part about rectifier tube. If one can afford it, the U52 rectifiers, as expensive as they may be, may make a more noticeable sonic improvement than power tubes. 

 

[budx3385]

+2

 

[froger]

  As I look around this thread, I see more posts about tubes and headphones than I do the Stratus.  In fact, posts (never mind, threads) about headphones on head-fi.org dominate those about amplifiers.  Even Dacs get more attention than amps.  Does anyone else find this odd, or maybe interesting?  I am at a loss to explain it....unless all amps sound the same, but headphones don't.
 
The tube posts, at least with reference to the Stratus are right-on, IMO.  But, in my experience, the rectifier makes as much, or even more, difference to the sonics than the power tubes.  Moreover, moving to a "higher grade" 5U4G type improves the sonics no matter what power tubes you are using. If I were a new buyer and wanted to spend some extra cash on tubes, I'd roll into a better rectifier, before I started to buy new power tubes.  
 
Now let me get back to headphones. If one reads a sampling of the headphone posts on this thread, one thing stands out: many flagship headphones are fussy, fussy about amplifiers and fussy about tubes. A lot of you report that. What I don't see reported very often (if at all) is how many of these flagship headphones have users tried in their systems before they settled on one that worked for them?  
 
So, I have a radical idea.  Before people go out and plunk down $1000+ plus on the best-ever headphone, why not look for headphones that a) sound good no matter what combination of tubes you use or upgrades you make to caps, resistors, etc. and b) sound better to you (not worse) with better tubes and appropriate upgrades? Basically, what I am suggesting is that this process of tube, parts, and headphones doesn't have to be entirely a random walk, with learning in-between steps.
 
The first headphone amp I owned was a Single Power MPX-3 + goodies.  It was a wonderful-sounding amp. and I only sold it to buy the Stratus.  I started with a pair of HD650s and added K701s when they came out.  No matter what combination of tubes I used on that amp, no matter how many caps and resistors I replaced,  they always sounded better.  The same was true of my Blue Circle SBH, to which I added a custom power supply, cap pack and then main unit, the sound from these amps never changed in character, but just sounded better.  I also have a headphone amp adapter from Blue Circle to use with my tube SET and PP amps (5 of them!) and had the same experience.  This was not true of the HD800 or the Audeze LCD-2, which both proved to be exceptionally fussy.  Nor was it true of the newer Hifiman headphones I tried.  They were all over the place.  
 
Recently, my beloved K701s fell apart from extended use and i snagged a used pair of K7XX headphones.  They are basically K701s with exaggerated bass and a bit wider sound-stage/channel separation.  They also are not fussy.  The same for my new HD650s.
 
Luck (good and bad) and common sense got me here.  The common sense part was not starting at the top of the headphone price ladder.  The good luck part was finding headphones that appealed to my range of sonic preferences and weren't fussy. The bad luck part was buying spending  $2500 on headphones before I was able to try them in my system for an extended period.  And there also something (a lot of something) to be said for improving the sonics at the amplifier end of the chain, before "rolling" headphones, something I learned from my bad luck experiences with the HD800s and the Audeze LDC-2.
 
In summary, to new buyers:
1.  Don't buy anything or change anything internally before you have owned the Stratus long enough to break it in and learn its sonics.
2.  If you have a pair of headphones you already love, stick with them for a while.  You'll probably love them on the Stratus.  
3.  Roll the rectifier, first (even if it costs $500-$1,000), and listen on your old headphones for sonic differences.  Hopefully, you will hear the differences, and they will be better.
4. The same holds true for changing amplifier parts.
5.  If your old headphones + tube rolling, etc. doesn't get you what you want, then beware.
6.  If ,you can't audition new headphones in your system, you may get lucky, but (again) beware of reviews.  A recent Stereophile review raved about the newest Audeze cans, but already some listeners call them fatiguing!
 
The Stratus is an excellent amplifier, stock.  

I have owned a number of rectifier tubes, EML mesh, WE274b, Ken Rad CKR, U52, but ended up using a relatively cheap RCA 5U4G with my HE1000. While I like the rest of the tubes with other headphones, I find it amusing to be using the cheapest rectifier tube for my preferred headphone after spending so much money on other rectifiers. Somehow, other rectifier tubes just do not synergize as well for the HE1000 in my system. Is there any "better" rectifier that you can recommend?

 

[Frihed89]

If your cans are sensitive to rectifier tubes and that is the sound you like, after trying many others, then you've done all you can, right?  I do find this odd.  But you might try a 5U4GB.  They swing more voltage.  They are not expensive.  I use 5U4GBs in a couple of other amps. Look for Raytheon black plates.  The "best" 5U4Gs are Japanese made Raytheons.  They have become very rare.  As I wrote, both my plebeian headphones react similarly to different rectifiers and power tubes. Or, have you tried a Brimar 5U4G, also rare? 

 

[froger]

Alright, will try to look around for your recommendations, thanks!

 

[vc1187]

I'm still a firm believer in tube combinations (i.e. tube synergy) with the Stratus rather than simply stating that rectifier x is better than rectifier y.  As previously mentioned, the HD650 will probably sound pretty decent with most tube combinations, but it certainly sounds better with particular tube combinations.  The same goes for any other headphone paired with the Stratus.
 
Certainly there are tubes that are considered better based on technicalities, but this doesn't account for the flavor added or personal taste for a specific sound signature that may match one pair of headphones better than another.  
For example, the Fostex TH-900, while easy to drive and generally sounds great even straight out of an iPhone, has a a recessed midrange, which can be seen from its FR.  Pair this with technically superb tubes like the U52 and EML 2A3 Mesh or AVVT 2A3 Mesh and you'll have an extremely hollow sounding midrange.  The synergy of these tubes, despite being 'better', just isn't there.  
 
Same idea with U52, KR Audio 2A3, and choice of driver as 6N1P-EV (specifically cryoset).  With the TH-900, this is on the clinical and cold side with a bright and harsh treble.  
 
Now if you change out the rectifier with a more intimate sounding one, like the RCA 5U4GB, you may experience better results due to the added warmth.  Yes, I'll admit I've tried these headphones and all of the tube combinations mentioned above, so this is my experience.
 
Most of the fun and part of being an audiophile for me at least is the ability to tinker with the sound and try different combinations in order to find what's optimal to my ears.  With this in mind, I believe my ears have become much pickier since I've had the options to tube roll in the Stratus.  Headphones that respond the most radically to tube changes are usually the most resolving and often will sound different based on changes to upstream equipment as well.

 

[Bogart24]

Given I currently have LCD-X and HD-800, what would be a good headphone add to get the most out of the Stratus? I was thinking about upgrading the HD800s to HD800Ss, (I'd keep both for a while then decide which I preferred), but then I wondered if I'd be better off getting HE-1000s or TH-900s or waiting for Focal Elear. Any advice?

 

[third_eye]

Given I currently have LCD-X and HD-800, what would be a good headphone add to get the most out of the Stratus? I was thinking about upgrading the HD800s to HD800Ss, (I'd keep both for a while then decide which I preferred), but then I wondered if I'd be better off getting HE-1000s or TH-900s or waiting for Focal Elear. Any advice?

 
I would strongly consider waiting until you have an opportunity to audition the Elear and Utopia. I'm pairing the Utopia with the Stratus now and it's sublime. 

 

[Bogart24]

I would strongly consider waiting until you have an opportunity to audition the Elear and Utopia. I'm pairing the Utopia with the Stratus now and it's sublime. 

Thanks. Makes sense except for the "I want it NOW" factor.

Put in a pre-order for Elear. (60-day return).

 

[budx3385]

   
I would strongly consider waiting until you have an opportunity to audition the Elear and Utopia. I'm pairing the Utopia with the Stratus now and it's sublime. 

 
Oooh. That was weighty and motivating, third_eye. Thanks for sharing. Have you heard the new Ether Flow, too? with your Stratus perhaps? 

 

[songmic]

 
I would strongly consider waiting until you have an opportunity to audition the Elear and Utopia. I'm pairing the Utopia with the Stratus now and it's sublime. 

 
Would you take the Utopia over HD800(S) with Stratus? I always thought HD800(S) was the end-game headphone for Stratus.

 

[RubyTiger]

   
Would you take the Utopia over HD800(S) with Stratus? I always thought HD800(S) was the end-game headphone for Stratus.

 
Hmmm.. I believe it's the Stratus that's the endgame amp for the HD800's instead. That's how I built my system anyhow.

 

[third_eye]

   
Would you take the Utopia over HD800(S) with Stratus? I always thought HD800(S) was the end-game headphone for Stratus.

   
Hmmm.. I believe it's the Stratus that's the endgame amp for the HD800's instead. That's how I built my system anyhow.

 
I believe that the Stratus is an endgame amp for the HD800 and that's how I too built my system. The Utopia is a very special headphone and brings some advantages over the HD800 in terms of overall resolution, speed, and dynamic range which for some genres is more noticeable than others. On the other hand, the HD800 still absolutely excels with the Stratus and is the more relaxing headphone to listen to while not giving up much to the Utopia in terms of technicalities or engagement. I would definitely recommend Stratus owners to audition the Utopia (and Elear) if the opportunity arises.

 

[songmic]

 
I believe that the Stratus is an endgame amp for the HD800 and that's how I too built my system. The Utopia is a very special headphone and brings some advantages over the HD800 in terms of overall resolution, speed, and dynamic range which for some genres is more noticeable than others. On the other hand, the HD800 still absolutely excels with the Stratus and is the more relaxing headphone to listen to while not giving up much to the Utopia in terms of technicalities or engagement. I would definitely recommend Stratus owners to audition the Utopia (and Elear) if the opportunity arises.

 
Haha, I did mean that HD800(S) is the endgame headphone for Stratus, but not the other way around. For me, endgame for HD800(S) would be something like DNA Silver Stellaris or EC Studio amp. What I meant was: if Stratus were your fixed amp, then you can't get better than HD800(S) with it. The reason I'm saying HD800(S) is because I used to own the HD800 but now the HD800S.
 
Based on preliminary reviews, the Utopia seems to best the HD800(S) in many ways. However, this was often the case when both headphones were served by solid-state amps that are inferior to Stratus. While I believe the Utopia could outperform HD800(S) when driven by lesser amps--heck, even I would take HD600/650 over HD800(S) on lesser SS amps--the thing about the Stratus is that it is a very high-end, even considered endgame by many, tube amp that supposedly has an incredible synergy with HD800(S) that allows it to scale tremendously to stratospheric heights. Also, I've read that Utopia sounded better on a high-quality solid-state amp than a tube amp (both of which were $3-4K+).
 
I know for a fact that Utopia > HD800(S) with lesser amps, and especially SS amps. But the Stratus is an amazing tube amp that loves HD800(S) like a match made in heaven. So what I'm wondering is, despite Utopia's affinity to SS amps, and despite HD800(S)'s clear advantage over Utopia in terms of synergy with Stratus and how it well scales with it, the Utopia still bests the HD800(S) in many of the aspects you described above?

 

[stuart1927]

So ...after the disappointment of my first KR audio 2A3 tubes....some good news!
 
After many emails to the original supplier, I had no luck in getting anywhere in terms of replacement tubes....in fact I got no response at all.
 
Finally, I decided to write an email to KR audio directly, not really expecting anything. However, I'm very impressed with them. They immediately sent me two replacement tubes at no cost. That's customer service. 
 
So, I'm trying the KR audio tubes again...I hope this pair  turn out to be more reliable....fingers crossed!
 
Stuart