[2359glenn]

  Which setting for the switch on the back to use 6336? 6AS7 or 5998?

Tyrell is right use the 5998 position for lowest impedance and highest power output.
Just don't use a wimpy rectifier when running the 6336.

 

[gibosi]

Leeds Radio's Etsy store has a nice pair of 6336B for a good price:
 
https://www.etsy.com/listing/216655587/pair-ge-6336b-vacuum-tubes-graphite?ref=shop_home_active_4&ga_search_query=6336
 
And I agree with him. Even though labeled as 6336A, the construction clearly indicates that these are in fact 6336B.

 

[Groundzero]

 
Tyrell is right use the 5998 position for lowest impedance and highest power output.
Just don't use a wimpy rectifier when running the 6336.

Is a 596 sufficient? 

 

[Xcalibur255]

  Is a 596 sufficient? 

It should be, but you might be running it fairly hard.  The 3DG4 has more headroom (350ma vs. 275ma on the 596).

 

[gibosi]

Earlier, Glenn said that the Cossor 53KU (250ma) should be fine with the 6336 in the 5998 mode.
 
http://www.head-fi.org/t/600110/2359glenn-studio/12525#post_12176232
 
So it seems that any rectifier that can provide at least 250ma and up should be good to go.

 

[2359glenn]

  Earlier, Glenn said that the Cossor 53KU (250ma) should be fine with the 6336 in the 5998 mode.
 
http://www.head-fi.org/t/600110/2359glenn-studio/12525#post_12176232
 
So it seems that any rectifier that can provide at least 250ma and up should be good to go.

Yes the 53KU should be OK.
If you still have the 3DG4 with it's 350ma use that.

 

[vc1187]

Stratus has arrived!
 
Initial impressions vs. Glenn OTL (Using HD800): The Stratus is truly a beautiful sounding amp, but the Glenn OTL doesn't miss a beat and to my ears is an equal match for the big blue beast.  Glenn is configured with a Sylvania 3DG4, 2 GEC 6080, and Ken Rad 6SN7GT Black Glass. Stratus configured and tested with both stock tubes and EML Mesh 2A3s, with a few different 5U4G tubes in the rectifier position.
 
Stratus with HD800:
Offers a larger soundstage with great realism.  HD800 still sounds like a bright headphone and retains all of its great qualities while minimizing the things that people generally criticize it for.  Stunning performance all across the board and dead quiet.
 
Glenn OTL:
Vocals have great body and presence and it's immediately noticeable when moving from Stratus to Glenn.  While the soundstage is smaller and there is slightly less sense of realism compared to the Stratus, the sound I am hearing is the ultimate level of what one would call 'low level of fatigue' when describing the HD800.
 
More impressions to come as I do some tube rolling on both amps.  Here's an updated photo.  The Stratus is much larger than I expected!
 

 

[JoelT]

  Stratus has arrived!....

 
Thanks for the impressions! Appreciated.
 
Just a note: I would add that the Ken Rad VT-231 6SN7GT isn't a very transparent or open sounding tube with the Glenn. The two I have seem to lack treble extension and are very warm and colored. I can see where some would find this sound appealing with the HD800, but it lacked realism to my ears. As with anything YMMV, etc. But I just wanted to point out that there are more transparent driver tube options than the KR, if that's what one is after.

 

[whirlwind]

  Stratus has arrived!
 
Initial impressions vs. Glenn OTL (Using HD800): The Stratus is truly a beautiful sounding amp, but the Glenn OTL doesn't miss a beat and to my ears is an equal match for the big blue beast.  Glenn is configured with a Sylvania 3DG4, 2 GEC 6080, and Ken Rad 6SN7GT Black Glass. Stratus configured and tested with both stock tubes and EML Mesh 2A3s, with a few different 5U4G tubes in the rectifier position.
 
Stratus with HD800:
Offers a larger soundstage with great realism.  HD800 still sounds like a bright headphone and retains all of its great qualities while minimizing the things that people generally criticize it for.  Stunning performance all across the board and dead quiet.
 
Glenn OTL:
Vocals have great body and presence and it's immediately noticeable when moving from Stratus to Glenn.  While the soundstage is smaller and there is slightly less sense of realism compared to the Stratus, the sound I am hearing is the ultimate level of what one would call 'low level of fatigue' when describing the HD800.
 
More impressions to come as I do some tube rolling on both amps.  Here's an updated photo.  The Stratus is much larger than I expected!
 

Wonderful gear there...just wonderful.

 

[ButtUglyJeff]

  ...The Stratus is much larger than I expected!
 
 

 
And I believe Don has a couple prototypes that are even larger...

 

[vc1187]

   
Thanks for the impressions! Appreciated.
 
Just a note: I would add that the Ken Rad VT-231 6SN7GT isn't a very transparent or open sounding tube with the Glenn. The two I have seem to lack treble extension and are very warm and colored. I can see where some would find this sound appealing with the HD800, but it lacked realism to my ears. As with anything YMMV, etc. But I just wanted to point out that there are more transparent driver tube options than the KR, if that's what one is after.

I agree with these impressions about the KR tube.  I actually hated this tube with the HD650, and much preferred a Tung Sol 6SN7GTB tube.  It made the HD650 sound closed in, dark, and veiled.  I guess I am just one of those people that doesn't find that detracting from the HD800's treble extension, soundstage, and causing it to be warmer to be a bad thing.  However, I do also appreciate the flip side where the HD800 benefits greatly from increased transparency without being overly ear-piercing in the highs.
 
I find the KR 6SN7GT in the Glenn OTL to make the HD800 a very pleasant pair of headphones to listen to.  Effects of tube rolling on the Glenn seem to have a larger impact than tube rolling on the Stratus when paired with the HD800.

 

[gibosi]

  More impressions to come as I do some tube rolling on both amps.  Here's an updated photo.
 

 
I second JoeIT's comments. IMHO, transparency is not a strength of the KR. Further, I don't find the Sylvania 3DG4 to be the most resolving rectifier either. So I look forward to hearing more about your impressions as you trial different tube combinations.
 
Currently, I am listening to the Cossor 53KU, Chatham/Tung-Sol 5998 (with the switch on) and a GEC B36. The big bass and warmth of the 5998s and the 53KU matched up with the characteristically airy and detailed GEC sound of the B36 is about as good as it gets, IMO.

 

[vc1187]

   
I second JoeIT's comments. IMHO, transparency is not a strength of the KR. Further, I don't find the Sylvania 3DG4 to be the most resolving rectifier either. So I look forward to hearing more about your impressions as you trial different tube combinations.
 
Currently, I am listening to the Cossor 53KU, Chatham/Tung-Sol 5998 (with the switch on) and a GEC B36. The big bass and warmth of the 5998s and the 53KU matched up with the characteristically airy and detailed GEC sound of the B36 is about as good as it gets, IMO.

Unless I am missing something, I don't know what switch you guys are talking about.  Perhaps mine doesn't have one?
 
Glenn, I have the same amp that Dubstep Girl reviewed earlier in this thread.  Does it have the switch mentioned and can it run 5998s?

 

[JoelT]

 
Unless I am missing something, I don't know what switch you guys are talking about.  Perhaps mine doesn't have one?
 
Glenn, I have the same amp that Dubstep Girl reviewed earlier in this thread.  Does it have the switch mentioned and can it run 5998s?

My amp doesn't have the 5998 bias switch either. I don't think the earlier builds did, from what I remember reading. It can still run 5998 tubes (I am currently using 5998 equiv), just not as optimally.

 

[whirlwind]

 

  More impressions to come as I do some tube rolling on both amps.  Here's an updated photo.
 

 
I second JoeIT's comments. IMHO, transparency is not a strength of the KR. Further, I don't find the Sylvania 3DG4 to be the most resolving rectifier either. So I look forward to hearing more about your impressions as you trial different tube combinations.
 
Currently, I am listening to the Cossor 53KU, Chatham/Tung-Sol 5998 (with the switch on) and a GEC B36. The big bass and warmth of the 5998s and the 53KU matched up with the characteristically airy and detailed GEC sound of the B36 is about as good as it gets, IMO.

I am enjoying the 5998 and B36 combo as well.....my rectifiers are PY500 and not the Cossor 53KU....but the signature is stunning.
 
Flac files...PS Audio Nuwave...HD800 is the rest of the chain.