[Frihed89]

  How many companies actually produced U52 tubes back them? I have done some research and in the end it seems all U52 were made by OSRAM. Was Marconi any different?

GEC and some others i have seen and forgotten, or haven't seen, but forgot!  Some French made brand, I think.

 

[m17xr2b]

As far as I know Gec, Osram, Brimar, Mullard, Marconi and Mwt are the same tube made in the same MOV factory. There are some variations with the gec u52 made in a different factory with a different plate construction.
There ia also an Mwt u52 which ia acually an rca 5u4g.
The one that everybody wants has the plates like the brimar in the picture

 

[drheadphone]

Just got my pair of WE275's. I can confirm the impressions discussed about this tube are very accurate. So friggin transparent and halographic with the HD800. Wish it had a little more low end grunt for modern music. I guess I'll keep the Shuguang Nature Sounds for that type of stuff. Great find guys!

Updated impressions: Experimenting with rectifiers with the WE275. Definitely prefer the EML Meshplate 5U4G most. I sense a midrange dip with the U52 and the Raytheon VT-244 just doesn't have enough bass or clarity.

 

[adamaley]

  I think you have answered the question yourself, with the EML tubes being more taut in bass and less lush sounding. I will enjoy the Shuguang Natural sound tubes with HE1000 if I never hear the EML mesh/solid plates as they are very lush and musical. However, IMO, the EML plates complements HE1000 better as the HE1000 does lack the bite at times compared to other headphones. With the EML tubes, the vocal of HE1000 is cleaner/clearer, more realistic in tonality and the bass is tighter, yet still remains very musical.

 
Have you compared the EML meshes to the solid plates? What would you say is the biggest deviating attribute? With the HE1K in mind, how did you decide on your preference?

 

[Bigsecret]

Just got my pair of WE275's. I can confirm the impressions discussed about this tube are very accurate. So friggin transparent and halographic with the HD800. Wish it had a little more low end grunt for modern music. I guess I'll keep the Shuguang Nature Sounds for that type of stuff. Great find guys!

Updated impressions: Experimenting with rectifiers with the WE275. Definitely prefer the EML Meshplate 5U4G most. I sense a midrange dip with the U52 and the Raytheon VT-244 just doesn't have enough bass or clarity.

I go back and forth between the EML Mesh 5U4G and the U52 with WE275. Both are very musical and engaging in different ways. You may want to try the Novosibirsk box plate 6N1P as driver. Maybe too airy for the HD800 but they have good punch and attack. One of the more affordable tube rolling options at about $20.

 

[vc1187]

Just got my pair of WE275's. I can confirm the impressions discussed about this tube are very accurate. So friggin transparent and halographic with the HD800. Wish it had a little more low end grunt for modern music. I guess I'll keep the Shuguang Nature Sounds for that type of stuff. Great find guys!

Updated impressions: Experimenting with rectifiers with the WE275. Definitely prefer the EML Meshplate 5U4G most. I sense a midrange dip with the U52 and the Raytheon VT-244 just doesn't have enough bass or clarity.

I noticed that the U52 does better with more forward sounding tube pairings.  Upon a lot of listening recently and comparisons to my other tube amps, I think the Shuguang Nature Sounds and the U52 are a bit too polite of a pairing.  The Shuguang Nature Sounds are more on the lush/warm side rather than neutral, so the U52 makes it too mushy.  I thought it sounded great at first because I was strictly listening at loud volumes to orchestral passages that would normally be overly bright and sharp.
 
I swapped back in an RCA 5U4GB and was rewarded with more presence in vocals as well as a much heftier mid-bass.  
 
The U52 seems to pair better with the stock Shuguang 2A3Bs to my ears.  That being said, the U52 works wonders with the Glenn OTL and HD800, since it's a more forward sounding amp than the Stratus.
 
I guess there really is no accounting for personal taste in this hobby.  Tube rolling is addictive though!

 

[RubyTiger]

Just my 2 cents; I prefer the EML 5U4G over the U52 with the WE275's. This is with the HD800's. I hear a reduction in high frequency information with the U52. I would call it a loss of ambience; the impression of acoustic space, such as the performing hall or venue in which a recoding was made. There's more reverb with the EML and a longer decay. The problem I experienced before between the EML and Naturals was a more edgy sound but not with the WE275's which are smoother. With the EML I still hear (like with the Naturals)  a strong presence within the 4kHz to 6kHz range or greater, meaning vocals and instruments sound closer and with great clarity. The EML and 275's seem to be a great combination with the HD800's.
 
The U52 and Naturals are a different story for me as well. I love that combination so as vc1187 say's, What works wonder's with one system might not fair so well in other's. But, I hope we can all agree the Psvane WE275's are really sweet sounding tubes.

 

[vc1187]

Yes, I think RubyTiger hits a key point when he says "What works wonder's with one system might not fair so well in other's" 
 
At a recent mini-meet that I hosted at my house, we had 2 pairs of HD800s: My completely stock HD800 and another member's HD800 modded with one of the newer mods that is supposed to go a level beyond the Anaxilus mod to reduce the painful treble spiking that the HD800 is notorious for.  The modded pair also had an aftermarket cable that was supposed to further reduce the brightness of the HD800.
 
At the end of that meet, the owner of the modded HD800 and the other members concluded that my pair of HD800 were simply superior in FR to the other HD800.  Even fully stock, my HD800 doesn't seem to exhibit as bad of a treble spike as the modded pair.  
To add onto this, my previous pair of HD800 sounded pretty bad with my ZD (same source, same DAC).  I couldn't believe that I bought into the hype and came out unsatisfied.  However, this pair of HD800 sounds excellent with the ZD!  My conclusion is that there is definitely noticeable variance in the HD800s.
 
To bring this back on topic of the Stratus and tube rolling, it may be why I find the Shuguang Nature Sounds and the U52 to be an overly smooth pairing with my particular HD800s.  I guess the next logical step is to check out the EML 5U4G, and then if my curiosity continues to get the better of me, the WE275s.

 

[Sorrodje]

@vc1187 : what kind of mod are you talking about ? Rugliner in the cups or something  "a la HD800S" ? 

 

[vc1187]

  @vc1187 : what kind of mod are you talking about ? Rugliner in the cups or something  "a la HD800S" ? 

I think it was close to this: 

 

[Sorrodje]

Ok rugliner mod ... measured but slight improvement in warmth especially in low mids . sssssssssix khz untouched  

 

[vc1187]

  Ok rugliner mod ... measured but slight improvement in warmth especially in low mids . sssssssssix khz untouched  

Ah ok, I did not know that, since I didn't actually read what the mod is supposed to do.  My experience with HD800 mods goes to the extent of the Anax mod that is posted on innerfidelity.  I performed it on my previous pair of HD800 and while it made a minor difference, that pair was still too bright and sharp for me.  The difference we heard at the mini-meet could only really be attributed to variance in the production of the HD800 since everything from source to amp was the same.
 
Anyway, so far with the Stratus, I still think the stock 2A3B tubes are the easiest to find a synergistic pairing of rectifier and driver tube for the HD800 that I own.  I'm having a hard time with the Nature Sound tubes, and still prefer the over all tonality of the 2A3B regardless of what rectifier and driver tube I try to pair the Nature Sounds with.

 

[froger]

Have you compared the EML meshes to the solid plates? What would you say is the biggest deviating attribute? With the HE1K in mind, how did you decide on your preference?

The solid plates have better imaging and a slightly tighter bass, which in my opinion, match HE-1000 better.

 

[adamaley]

Thanks @froger

 

[vc1187]

I just noticed that my findings regarding the U52 tube pairings and the stratus have been discussed by both drheadphone and froger on this thread in 2014. Better late to the game than never, I guess!

Time to hunt down a Ken Rad CKR 5u4g vt-244.