[zoneykid]

  Zoney...the two tubes you are looking at are awesome (especially the first GE Holland 6AQ8)
 
If you go for number two, pick the one that reads
~~12166/12640 umhos
 
Closest balance to both sides
 
I have both, both sound great but the 6AQ8 is amazing...

I ended up getting the GE, it finally arrived today and I have to say, it does sound quite amazing. It still sounds open and clear like the EH tube but now it feels like all the lower frequencies I didn't realize were missing are there again.
I totally recommend this tube to anyone that has a pair of Beyer DT990s in 250ohm.
 
Only issue now is there's a hair in the driver of my DT990s which causes a vibrating noise on low frequencies, and with this tube it's much more apparent now due to the full bass. Guess it's time to send these in for repair finally.

 

[MrEleventy]

Is it in the driver or on the driver? It's an easy fix.

 

[zoneykid]

In the driver it would seem from what I've read in other posts, there's a paper covering on it and I don't want to void my warranty.

 

[arcorob]

  Here is what my tube seller said about my possible CCa:
 
 
 
By A9 he is talking about on the internal shield seen here:
 

Great to see...CCa's were made for military equipment use...but of course found their way elsewhere. Much like the GE and RCA JG's, WA's ...

 

[MrEleventy]

In the driver it would seem from what I've read in other posts, there's a paper covering on it and I don't want to void my warranty.

That's on the driver, it's easy to get to but if have a warranty, take advantage of it.

 

[NCSUZoSo]

Guys I don't know who had the bright idea of 25mm of height space, but it isn't true.  I would say you have more like 20mm, here is how I got my caps to fit:
 

 

[arcorob]

  Never mind ...here you go...form mouser...these are your specs, right ?
 
http://www.mouser.com/ProductDetail/Nichicon/URZ1E332MHD/?qs=sGAEpiMZZMtZ1n0r9vR22cavfLNkWkbI9aMB5dF6xM0%3d

Wasn't me..I gave you the 20mm spec
 

 

[NCSUZoSo]

Anyway initial impressions on replacing everything but the last coupling caps on the headphone PCB;
 
The first thing that you notice is the sound stage is wider, seems much wider.  Also even with a Siemens A9 6992 (possible CCa), the clarity is even more detailed than before, at first it seems like you lost a bit off bass, but then you realize it's just less boomy and tighter instead.

 

[arcorob]

  Anyway initial impressions on replacing everything but the last coupling caps on the headphone PCB;
 
The first thing that you notice is the sound stage is wider, seems much wider.  Also even with a Siemens A9 6992 (possible CCa), the clarity is even more detailed than before, at first it seems like you lost a bit off bass, but then you realize it's just less boomy and tighter instead.

You'll get your bass back. People don't always believe (two schools of thought) but caps DO need break-in....they'll be a little hyperdetailed at first ..then they will smooth out...give it a good 8 hour burn in ...then a few days...watch the transformation...
 
A recent recap of my main amp scared the daylights out of me...sounded awful...till after a few hours ..then it was beautiful...

 

[Salvatore]

  Here we go again. I love when people speak in explicit's ..but are not correct.

 
Not cool.

 

[Salvatore]

Amperex, Mullard, Philips, and Valvo Tube Codes
 

Most Amperex, Mullard, Philips and Valvo tubes are marked with a group of symbols which contain coded information relating to the type, place of manufacture or country of origin, and the date of manufacture. Apart from the interest of knowing when and where a tube was made, the code group can still provide useful type identification when the commercial markings have become illegible.

 
There were two types of code formats that used the same tube type codes, which were in use from 1948 until these companies stopped the manufacture of standard receiving tubes. The code format changed about 1955 or 1956. There are some deviations to this rule, and in certain manufacturing plants not all of the code protocol was followed exactly, with every batch of tubes. Prior to 1955, Mullard used a purely numerical code for encoding the tube type, but then adopted the code change as listed here after that. Therefore, for tubes made after 1955 by all three of these large European manufacturers, the code is fairly uniform and straightforward to decipher using these code lists. Of course, as mentioned above, there are deviations in the code that vary from factory to factory and from year to year. This list is presented as found on original Philips documentation. Brent Jessee Recording makes no claims as to accuracy, and presents this information for your use "as is" and "as found".
 
THE ELEMENTS OF THE TUBE CODE:
The digits are often found near the bottom of the glass on the side of the tube. They consist of two or three lines of numbers, letters, and sometimes symbols. They will nearly all use the following convention, from left to right, top to bottom of the code group:
 
TUBE TYPE:
This may be one, two, or three alphanumerics or symbols. For example, the code GA means the tube is a type ECC88, which is also a 6DJ8. These codes will be listed later in this webpage. Pretty straightforward, huh? Take notes, it gets stranger from this point on......

 

[Salvatore]

With all the fakes and relabels I'd be very interested of those codes. I wouldn't buy any of those expensive tubes without proper etching.

 

[arcorob]

  With all the fakes and relabels I'd be very interested of those codes. I wouldn't buy any of those expensive tubes without proper etching.

Salvatore, that is copied from Brent Jesse.  Nowhere does he say these codes are etched. He is just explaining how the codes work. Period.
 
Lets just leave it like LWRS said. Many European tubes have etched codes. Most American do not.

 

[Salvatore]

 
Salvatore, that is copied from Brent Jesse.  Nowhere does he say these codes are etched. He is just explaining how the codes work. Period.
 
Lets just leave it like LWRS said. Many European tubes have etched codes. Most American do not.

 
Yes those who have been reading my posts know that I've been quoting Brent Jessee several times before. It also says Brent Jessee in the text so I'm not claiming it to be my own text. Not all tubes have visible factory codes I know, but for what I know also at least some of american Amperexes should have codes. What I'm trying to say is that there are lots of beginners out here and it's important that they know how to interpret codes and look for them. If tubes are not identified by codes you should at least tell people about the triodes, getters, supports, shields etc. I wouldn't encourage beginners to buy expensive tubes based only on painted text even though many of the best tubes might only have such. If Coil has room for improvement in his expression of thoughts so does you. Lets not try to constantly troll or diss people about their impressions or opinions.

 

[NCSUZoSo]

Yea Coil, I hope so too and mine doesn't sound sterile, just a lack of the original bass.
 
my caps are as follows:
 
ELNA SILMIC II 330uF (x2)
Nichicon FW 3300uF (x2)
ELNA Cerafine 470uF (x2)
 
 
If you look at the picture I posted:
 

 
 
The black cap in the left (SILMIC II) at the top of the picture, I had to actually add the leads back to..  This is because I thought they were going to fit and it was so close I couldn't find out without putting the bottom on, which I didn't do until I soldered it.  Do running these long leads or in my case soldering the leads back on the cap with only a few millimeters left on the cap affect the values?  Or is that just the guitarist in me trying to make an issue out of everything?